bluuebunny/crossref_metadata_2025 huggingface dataset:
Stimulus and Potassium-Induced Epileptiform Activity in the Human Dentate Gyrus from Patients with and without Hippocampal Sclerosis
Authors: Gabriel Siegrun , Njunting Marleisje , Pomper Joern K. , Merschhemke Martin , Sanabria Emilio R. G. , Eilers Alexander , Kivi Anatol , Zeller Melanie , Meencke Heinz-Joachim , Cavalheiro Esper A. , Heinemann Uwe , Lehmann Thomas-Nicolas
Published: November 2004

Hippocampal specimens resected to cure medically intractable temporal lobe epilepsy (TLE) provide a unique possibility to study functional consequences of morphological alterations. One intriguing alteration predominantly observed in cases of hippocampal sclerosis is an uncommon network of granule cells monosynaptically interconnected via aberrant supragranular mossy fibers. We investigated whether granule cell populations in slices from sclerotic and nonsclerotic hippocampi would develop ictaform activity when challenged by low-frequency hilar stimulation in the presence of elevated extracellular potassium concentration (10 and 12 mm) and whether the experimental activity differs according to the presence of aberrant mossy fibers.

We found that ictaform activity could be evoked in slices from sclerotic and nonsclerotic hippocampi (27 of 40 slices, 14 of 20 patients; and 11 of 22 slices, 6 of 12 patients, respectively). However, the two patient groups differed with respect to the pattern of ictaform discharges and the potassium concentration mandatory for its induction. Seizure-like events were already induced with 10 mmK+. They exclusively occurred in slices from sclerotic hippocampi, of which 80% displayed stimulus-induced oscillatory population responses (250-300 Hz). In slices from nonsclerotic hippocampi, atypical negative field potential shifts were predominantly evoked with 12 mmK+. In both groups, the ictaform activity was sensitive to ionotropic glutamate receptor antagonists and lowering of [Ca2+]o.

Our results show that, in granule cell populations of hippocampal slices from TLE patients, high K+-induced seizure-like activity and ictal spiking coincide with basic electrophysiological abnormalities, hippocampal sclerosis, and mossy fiber sprouting, suggesting that network reorganization could play a crucial role in determining type and threshold of such activity.
State Anxiety Modulation of the Amygdala Response to Unattended Threat-Related Stimuli
Authors: Bishop Sonia J. , Duncan John , Lawrence Andrew D.
Published: November 2004

Findings from fear-conditioning studies in rats and functional neuroimaging with human volunteers have led to the suggestion that the amygdala is involved in the preattentive detection of threat-related stimuli. However, some neuroimaging findings point to attentional modulation of the amygdala response. The clinical-cognitive literature suggests that the extent to which the processing of threat-related stimuli is modulated by attention is crucially dependent on participants' anxiety levels. Here, we conducted a functional magnetic resonance imaging study with 27 healthy volunteers to examine whether amygdala responsivity to unattended threat-related stimuli varies with individual differences in state anxiety. Pairs of houses and faces (both fearful or neutral in expression) were presented, and participants attended to either the faces or the houses and matched these stimuli on identity. “Low-anxious” participants showed a reduced amygdala response to unattended versus attended fearful faces, but “high-anxious” participants showed no such reduction, having an increased amygdala response to fearful versus neutral faces regardless of attentional focus. These findings suggest that anxiety may interact with attentional focus to determine the magnitude of the amygdala response to threat-related stimuli.
“What” Becoming “Where”: Functional Magnetic Resonance Imaging Evidence for Pragmatic Relevance Driving Premotor Cortex
Authors: Wolfensteller Uta , Schubotz Ricarda I. , von Cramon D. Yves
Published: November 2004

Previous studies using the serial prediction task (SPT) have shown that attending to the locations of objects activates the dorsal part of premotor cortex more than attending to the sizes of objects. The opposite holds for the ventral part of the premotor cortex. The present study used functional magnetic resonance imaging to investigate whether the learning of arbitrary stimulus-response mappings influences this functional dissociation. One experimental group learned to assign stimuli to response buttons based on stimulus size; another group did so based on stimulus location. More specifically, one-half of the participants in both experimental groups learned to assign stimuli to finger movements of their right hand, whereas the other half assigned stimuli to finger movements of their left hand. During scanning, all participants performed both size SPT and location SPT. Thus, we investigated the effects of the attended stimulus property (size or location), the motor effector assigned to it (fingers of left or right hand), and the spatial arrangement of the targets (the same in all groups). As expected, without motor training, the dorsal premotor cortex was less activated during size SPT compared with location SPT. The opposite held for ventral premotor cortex. With motor training, however, this differential activity pattern vanished. Activity in dorsal premotor cortex reflected neither the attended stimulus property nor the motor effector assigned to it. Instead, its activity may be related to the spatial properties of the response targets once some object property, such as size, takes on the “pragmatic relevance” of a spatially directed response.
Fear-Potentiated Startle in Rats Is Mediated by Neurons in the Deep Layers of the Superior Colliculus/Deep Mesencephalic Nucleus of the Rostral Midbrain through the Glutamate Non-NMDA Receptors
Authors: Zhao Zuowei , Davis Michael
Published: November 2004

The amygdala sends heavy and broad projections to the rostral midbrain including the periaqueductal gray (PAG), the deep layers of the superior colliculus/deep mesencephalic nucleus (deep SC/DpMe), and the lateral mesencephalic reticular formation (MRF) that in turn project to the nucleus reticularis pontis caudalis (PnC), an obligatory relay in the primary acoustic startle circuit. Chemical lesions or inactivation of these areas blocked fear-potentiated startle, suggesting that these areas serve as a relay between the amygdala and the PnC. In the present study, we tried to determine more precisely which of these sites were critical for fear-potentiated startle and the role of glutamate receptors in this site in mediating fear-potentiated startle. Local infusion of the non-NMDA receptor antagonist 2,3-dihydroxy-6-nitro-7-sulfamoylbenzo(F)-quinoxaline (NBQX) dose-dependently blocked fear-potentiated startle when infused into the deep SC/DpMe before testing but had no effect on baseline startle amplitude. NBQX did not block fear-potentiated startle when infused before training. The same dose of NBQX infused into the dorsal/lateral PAG, the lateral MRF, or the superficial layers of the SC did not affect fear-potentiated startle. However, NBQX tended to reduce contextual freezing when infused into the dorsal/lateral PAG. These findings suggest that the deep SC/DpMe is the site that serves as a critical output relay between the amygdala and the PnC in mediating fear-potentiated startle and that glutamatergic transmission is required for this action.
Blockade of Nogo-66, Myelin-Associated Glycoprotein, and Oligodendrocyte Myelin Glycoprotein by Soluble Nogo-66 Receptor Promotes Axonal Sprouting and Recovery after Spinal Injury
Authors: Li Shuxin , Liu Betty P. , Budel Stephane , Li Mingwei , Ji Benxiu , Walus Lee , Li Weiwei , Jirik Adrienna , Rabacchi Sylvia , Choi Eugene , Worley Dane , Sah Dinah W. Y. , Pepinsky Blake , Lee Daniel , Relton Jane , Strittmatter Stephen M.
Published: November 2004

The growth of injured axons in the adult mammalian CNS is limited after injury. Three myelin proteins, Nogo, MAG (myelin-associated glycoprotein), and OMgp (oligodendrocyte myelin glycoprotein), bind to the Nogo-66 receptor (NgR) and inhibit axonal growthin vitro. Transgenic or viral blockade of NgR function allows axonal sproutingin vivo. Here, we administered the soluble function-blocking NgR ectodomain [aa 27-310; NgR(310)ecto] to spinal-injured rats. Purified NgR(310)ecto-Fc protein was delivered intrathecally after midthoracic dorsal over-hemisection. Axonal sprouting of corticospinal and raphespinal fibers in NgR(310)ecto-Fc-treated animals correlates with improved spinal cord electrical conduction and improved locomotion. The ability of soluble NgR(310)ecto to promote axon growth and locomotor recovery demonstrates a therapeutic potential for NgR antagonism in traumatic spinal cord injury.
Increased Expression of theDrosophilaVesicular Glutamate Transporter Leads to Excess Glutamate Release and a Compensatory Decrease in Quantal Content
Authors: Daniels Richard W. , Collins Catherine A. , Gelfand Maria V. , Dant Jaime , Brooks Elizabeth S. , Krantz David E. , DiAntonio Aaron
Published: November 2004

Quantal size is a fundamental parameter controlling the strength of synaptic transmission. The transmitter content of synaptic vesicles is one mechanism that can affect the physiological response to the release of a single vesicle. At glutamatergic synapses, vesicular glutamate transporters (VGLUTs) are responsible for filling synaptic vesicles with glutamate. To investigate how VGLUT expression can regulate synaptic strengthin vivo, we have identified theDrosophilavesicular glutamate transporter, which we name DVGLUT. DVGLUT mRNA is expressed in glutamatergic motoneurons and a large number of interneurons in theDrosophilaCNS. DVGLUT protein resides on synaptic vesicles and localizes to the presynaptic terminals of all known glutamatergic neuromuscular junctions as well as to synapses throughout the CNS neuropil. Increasing the expression of DVGLUT in motoneurons leads to an increase in quantal size that is accompanied by an increase in synaptic vesicle volume. At synapses confronted with increased glutamate release from each vesicle, there is a compensatory decrease in the number of synaptic vesicles released that maintains normal levels of synaptic excitation. These results demonstrate that (1) expression of DVGLUT determines the size and glutamate content of synaptic vesicles and (2) homeostatic mechanisms exist to attenuate the excitatory effects of excess glutamate release.
Orexin Neurons Function in an Efferent Pathway of a Food-Entrainable Circadian Oscillator in Eliciting Food-Anticipatory Activity and Wakefulness
Authors: Mieda Michihiro , Williams S. Clay , Sinton Christopher M. , Richardson James A. , Sakurai Takeshi , Yanagisawa Masashi
Published: November 2004

Temporal restriction of feeding can entrain circadian behavioral and physiological rhythms in mammals. Considering the critical functions of the hypothalamic orexin (hypocretin) neuropeptides in promoting wakefulness and locomotor activity, we examined the role of orexin neurons in the adaptation to restricted feeding. In orexin neuron-ablated transgenic mice, the food-entrained rhythmicity ofmPer2expression in the brain and liver, the reversal of the sleep-wake cycle, and the recovery of daily food intake were unaltered compared with wild-type littermates. In contrast, orexin neuron-ablated mice had a severe deficit in displaying the normal food-anticipatory increases in wakefulness and locomotor activity under restricted feeding. Moreover, activity of orexin neurons markedly increased during the food-anticipatory period under restricted feeding in wild-type mice. Orexin neurons thus convey an efferent signal from putative food-entrainable oscillator or oscillators to increase wakefulness and locomotor activity.
Vascular Endothelial Cells Promote Acute Plasticity in Ependymoglial Cells of the Neuroendocrine Brain
Authors: De Seranno Sandrine , Estrella Cecilia , Loyens Anne , Cornea Anda , Ojeda Sergio R. , Beauvillain Jean-Claude , Prevot Vincent
Published: November 2004

Glial and endothelial cells interact throughout the brain to define specific functional domains. Whether endothelial cells convey signals to glia in the mature brain is unknown but is amenable to examination in circumventricular organs. Here we report that purified endothelial cells of one of these organs, the median eminence of the hypothalamus, induce acute actin cytoskeleton remodeling in isolated ependymoglial cells and show that this plasticity is mediated by nitric oxide (NO), a diffusible factor. We found that both soluble guanylyl cyclase and cyclooxygenase products are involved in this endothelial-mediated control of ependymoglia cytoarchitecture. We also demonstrate by electron microscopy that activation of endogenous NO release in the median eminence induces rapid structural changes, allowing a direct access of neurosecretory axons containing gonadotropin-releasing hormone (GnRH) (the neuropeptide controlling reproductive function) to the portal vasculature. Localin vivoinhibition of NO synthesis disrupts reproductive cyclicity, a process that requires a pulsatile, coordinated delivery of GnRH into the hypothalamic-adenohypophyseal portal system. Our results identify a previously unknown function for endothelial cells in inducing neuroglial plasticity and raise the intriguing possibility that endothelial cells throughout the brain may use a similar signaling mechanism to regulate glial-neuronal interactions.
The Inner Schema of Borderline States and Its Correction During Psychotherapy: A Cognitive-Evolutionary Approach
Authors: Liotti Giovanni
Published: November 2004

A growing body of clinical reflections and empirical evidence supports the hypothesis that an inner interpersonal schema stemming from attachment disorganization underlies the borderline states. This article begins with a brief outline of attachment disorganization and a discussion of its relevance for the understanding of psychopathological developments in general. Then it offers a review of the evidence supporting the hypothesis of a specific link between attachment disorganization and borderline states. The relevance of evolutionary psychology for understanding the genesis of the inner schema related to attachment disorganization and its link to the clinical features of borderline patients is the next topic of the article. Finally, some consequences of this evolutionary approach in the treatment of borderline patients are outlined.
Group Cognitive-Behavioral Treatment of Depression and the Interaction of Demographic Variables
Authors: Gelhart Robert P. , Hand-Ronga Nancy , King Heather L.
Published: November 2004

Response levels of 92 depressed subjects with differing demographic profiles to a standardized small-group CBT intervention were examined. Findings were based on combined groups wherein adults participated in 12 two-hour skill-building sessions conducted in 8-week periods. Participants were assessed for levels of depression, hopelessness, anxiety, and social adjustment at pre- and post-test, and 1, 6, 12, 18, and 24 months following treatment. The intervention was effective in the treatment of unipolar depression for all groups, and demographic variables were found to have various significant functional relationships with treatment outcome. Gender combined with marital status, and the separate results of education level, employment status, and income level all indicate different treatment effects.
The Development of Depressogenic Cognitive Styles: The Role of Negative Childhood Life Events and Parental Inferential Feedback
Authors: Crossfield Alisa G. , Alloy Lauren B. , Gibb Brandon E. , Abramson Lyn Y.
Published: November 2004

This study examined the role of childhood negative life events and parental inferential feedback in the development of cognitive vulnerability to depression. Students with negative cognitive styles, previously shown to be at high cognitive risk for depression, were predicted to have a greater history of negative childhood life events and negative parental inferential feedback than were students at low cognitive risk for depression. It was further predicted that parental inferential feedback would moderate the relationship between negative childhood life events and cognitive risk for depression. Finally, the associations between subsets of childhood negative life events and cognitive risk for depression were examined. No significant main effects were found for childhood negative life events or parental inferential feedback. The interaction of these 2 variables was significantly associated with cognitive risk status. Specifically, high levels of negative childhood life events in combination with negative maternal inferential feedback were associated with students’ cognitive risk for depression. When the negative childhood life events were divided into subsets, no main effects or interactions were found.
Dysthymia and Major Depression: Distinct Conditions or Different Stages Along a One-Dimensional Continuum?
Authors: Pössel Patrick
Published: November 2004

Until recently researchers have discussed whether dysthymia and major depression represent distinct conditions or rather different stages along a one-dimensional continuum. This study addresses this question by examining the belief systems of normal, dysthymic, and depressed participants. We explored participants’ beliefs and differentiated between positive and negative as well as between core and peripheral beliefs. Normal participants showed fewer negative beliefs and negative peripheral beliefs than the dysthymic group, whereas normal participants had more positive beliefs and positive core beliefs as well as fewer negative core beliefs than the depressed group. The hypothesized one-dimensional continuum could not be demonstrated for the belief systems. Instead, the data point to the conclusion that our idea of a one-dimensional continuum reaching from normal to dysthymic to depressed was too simple. Apparently, the differences in the belief systems reported here are related to the chronic character and severity of the mood disorder.
The Relationship Between Core Beliefs and a History of Eating Disorders: An Examination of the Life Stories of University Students
Authors: Sarin Sabina , Abela John R. Z.
Published: November 2004

The goal of the current study was to examine the relationship between core beliefs and a history of eating disorders using a retrospective design. Sixty-three university students completed self-report measures assessing current depressive symptoms. They also completed a semistructured interview assessing current and past histories of eating disorders. The presence of core beliefs was identified through an examination of participants’ life stories. Core beliefs were associated with past histories of both anorexia and bulimia nervosa, even after controlling for current depressive symptoms and eating disorders. Further analyses revealed that core beliefs centering around themes of disconnection and rejection, other-directedness, and overvigilance and inhibition were associated with past histories of anorexia nervosa, whereas core beliefs centering around themes of disconnection and rejection, impaired limits, and overvigilance and inhibition were associated with past histories of bulimia nervosa. These findings provide preliminary support for recent theoretical models highlighting the potential importance of core beliefs in the etiology of eating disorders.
Group CBT for Clients With a First Episode of Schizophrenia
Authors: Lecomte Tania , Leclerc Claude , Wykes Til , Lecomte Jocelin
Published: November 2004

This article describes the rationale for and the content of a 24-session group cognitive-behavioral therapy (CBT) tailored to the needs of individuals following a first episode of psychosis. The CBT group approach aims to increase coping with psychotic symptoms as well as help clients deal with other clinical realities such as low self-esteem, stress, anxiety, depression, suicide and substance abuse. Qualitative results, regarding process and satisfaction with treatment, are promising and suggest further investigation of this group intervention.
The Infant Care Questionnaire: Assessment of Reliability and Validity in a Sample of Healthy Mothers
Authors: Secco Loretta
Published: November 2004

Few instruments are available to assess perceptions of competence in the specific maternal role function of infant care provider. This article reports on a methodological study of the development and evaluation of the Infant Care Questionnaire (ICQ), a self-report scale designed to measure the mother’s perceptions of her abilities and competence as an infant care provider. The sample consisted of healthy low-risk primiparous and multiparous mothers (N = 164) of term infants. Principal components factor analysis with a Varimax rotation produced a three factor solution that explained 42% of the total variance. The three factors were Mom&Baby, Emotionality, and Responsiveness with Cronbach alpha coefficients of .86, .79, and .58, respectively. Validity evidence included higher Mom&Baby scores for multiparous mothers, F (1, 139) = 10.78, p = .001; those with greater time in the mothering role, F (2, 138) = 21.78, p = .000; and a significant correlation with the similar Maternal Confidence Scale, r (155) = .48, p = .000. Acquisition of competence was shown in a greater proportion of mothers rated “competent” at five weeks compared with one week postnatal, χ2 (1, N = 156) = 22.77, p = .000. While the ICQ demonstrated adequate reliability and validity, establishment of clinical relevance and appropriateness with other groups is required.
An Introduction to Rasch Measurement for Scale Development and Person Assessment
Authors: Smith Everett V. , Conrad Karen M. , Chang Karen , Piazza Jo
Published: November 2004

This article: a) outlines some of the limitations of True Score Theory, b) discusses some advantages of Rasch measurement, and c) compares the results of Rasch and factor analytic techniques applied to a common data set. Using a mail survey, 206 female members of a national nursing association completed Ryckman’s (1982) Perceived Physical Ability Scale. Exploratory factor analysis identified one factor with a Cronbach alpha of .78. Rasch fit statistics also identified one dimension with a person reliability of .76. Rasch methods were also used to investigate the rating scale functioning, additional construct validity issues, and person diagnosis. Discrepancies between the two estimates of internal consistency are discussed and differences in the utility of the two methodologies are reviewed.
Infrared investigation of the sequestration of toluene vapor on clay minerals
Authors: Chang Meei-Ling , Wu Shian-Chee , Chen Pei-Jen , Cheng Shu-Chun
Published: November 2004

The Ca-exchanged clays were used to investigate the sorption of toluene under both high and low relative humidity conditions. According to the observed rates of sorption and desorption and the Fourier transform infrared (FTIR) spectra of sorbed toluene, the sorbate molecules on clays can be divided into three categories: labile (gaslike) phase, slow sorption (liquidlike) phase, and resistant-to-desorption phase with sorption/desorption time scales of less than 30 min, several hours, and several weeks, respectively. Aging changed the spectroscopic characteristics of the sorbed sorbates and contributed to the irreversibility of the sorption under both high and low relative humidity. Irreversibly sorbed portions of the sorbates and new characteristic peaks identified with FTIR spectrometry suggest the existence of chemical transformation of sorbed species under both high and low relative humidity conditions. It is suggested that the clay minerals, acting as catalysts, may contribute to abiotic natural attenuation of volatile organic aromatic hydrocarbons in soils.
Inheritance of mercury tolerance in the aquatic oligochaete Tubifex tubifex
Authors: Vidal Dora Elva , Horne Alex John
Published: November 2004

Resistance to contaminants is an important yet unmeasured factor in sediment toxicity tests. The rate at which mercury resistance develops and its genetic persistence in the oligochaete worm Tubifex tubifex were studied under laboratory conditions. Worms were raised for four generations under two different sediment treatments, one reference clean sediment, the other contaminated with mercury. Worms raised in mercury-contaminated sediment developed mercury tolerance that persisted even when the worms were raised for three subsequent generations in clean sediment. Mercury tolerance was determined by comparative water-only toxicity tests with mercury as the only stressor. Control worms had a mean lethal concentration (LC50) of 0.18 mg/L−1. Worms exposed to high levels of mercury in sediment had high mercury tolerance with a mean LC50 of 1.40 mg/L−1. When mercury-tolerant and control mercury-intolerant worms were crossed, their descendants also demonstrated mercury tolerance during lethal toxicity tests. The LC50 for worm descendants resulting from this cross was 1.39 mg/L−1. Adaptation to mercury exposures occurred rapidly in this group of worms and appears to be due to both phenotypic and genotypic mechanisms. Development of contaminant resistance and adaptation may be common phenomena in aquatic benthic invertebrates, which should be considered during the design and interpretation of toxicity tests.
Age and accumulation of persistent organochlorines: A study of arctic-breeding glaucous gulls (Larus hyperboreus)
Authors: Bustnes Jan Ove , Bakken Vidar , Skaare Janneche Utne , Erikstad Kjell Einar
Published: November 2004

We studied the relationship between increasing age and blood concentrations of four persistent organochlorines (OCs), hexachlorbenzene (HCB), oxychlordane, p,p′-dichlorodiphenyldichloroethylene (DDE), and 2,2′,4,4′,5,5′-hexachlorbiphenyl (PCB-153), in arctic-breeding glaucous gulls (Larus hyperboreus). We measured OC concentrations in 31 individuals of known age and took repeated blood samples of 64 individuals in different years, either one year apart or three or four years apart. The age of individuals was not related to the blood concentrations for any of the four compounds, and in birds whose values were measured repeatedly, there was no effect of the length of time (number of years) between sampling events on the relative change in OC concentration. This indicates that steady-state levels were reached before the age of first breeding. However, breeding area significantly influenced the changes in OC concentration between sampling events. In areas in which birds fed on prey from higher trophic levels, the OC concentrations showed large increases between sampling events; in areas in which birds fed at lower trophic levels, OC concentrations increased relatively little or not at all. This indicates that individual birds had different equilibrium concentrations, which are reached at different ages depending on the intake of OCs through the food. It also indicates that some individuals had not reached steady-state concentrations at the onset of reproduction. Changes in body condition and amount of blood lipids were of lesser importance than trophic level and influenced the concentrations of HCB and oxychlordane more strongly than DDE and PCB-153. In conclusion, this study indicates that steady-state concentrations of persistent OCs are reached early in life in most glaucous gulls, considering the long life span of the species.
Impact of the plant rhizosphere and augmentation on remediation of polychlorinated biphenyl contaminated soil
Authors: Singer Andrew C. , Smith Daniel , Jury William A. , Hathuc Khoiviet , Crowley David E.
Published: November 2004

This study investigated the interactive effects of bioaugmentation, biostimulation, and the rhizosphere during remediation of Aroclor 1242-contaminated soil. Treatments were repeatedly augmented with polychlorinated bipheny (PCB)-degrading bacteria, inducers (carvone and salicylic acid), surfactant (sorbitan trioleate), minimal salts medium in a 20-cm high soil column, or a combination of these elements. Soils containing a single Brassica nigra plant achieved 61% PCB removal in the 0 to 2 and 2 to 6 cm depths after 9 weeks of bioaugmentation, whereas only 43 and 14% PCB removal, respectively, was achieved in unplanted controls. Gas diffusion coefficients of 13.0 and 5.0 × 10−7 m2 s−1 were calculated from a methane diffusion assay for planted and unplanted soils respectively, indicating the positive effect of plant roots on gas diffusion into the soil. A second, modified column study removed 87, 73, 63, and 45% of PCB after 12 weeks in the 0 to 5, 5 to 11, 11 to 26, and 26 to 35 cm depths, respectively, in planted-bioaugmented soils, whereas 65, 54, 53, and 47% of PCB was removed from the planted-minimal salts treatment, respectively. Shifts in the soil microbial community structure were demonstrated by denaturing gradient gel electrophoresis of bacterial 16S ribosomal DNA. Results support that Brassica nigra directly contributed to accelerated PCB removal by increased oxygen diffusion, amendment infiltration, and microbial enrichment.
Anaerobic transformation of compounds of technical toxaphene. I. Regiospecific reaction of chlorobornanes with geminal chlorine atoms
Authors: Ruppe Steffen , Neumann Anke , Vetter Walter
Published: November 2004

Technical toxaphene (Melipax) and the single compounds of technical toxaphene (CTTs) 2,2,5-endo, 6-exo, 8,8,9,10- octachlorobornane (B8-806), 2,2,5-endo, 6-exo, 8,9,9,10-octachlorobornane (B8-809), 2,2,5,5,8,9,9,10,10-nonachlorobornane (B9- 1025), 2-endo, 3-exo, 5-endo, 6-exo, 8,8,9,10,10-nonochlorobornane (B9-1679), 2-endo, 3-exo, 5-endo, 6-exo, 8,9,10,10-octachlorobornane (B8-1414), 2-endo, 3-exo, 5-endo, 6-exo, 8,8,9,10-octachlorobornane (B8-1412), and 2-exo, 3-endo, 5-exo, 9,9,10,10-heptachlorobornane (B7-1453) were treated with suspensions of the anaerobic bacterium Dehalospirillum multivorans. After 7 d, more than 50% of technical toxaphene was transformed, and the relative amount of early eluting CTTs increased. After 16 d, only 2-exo, 3-endo, 6-exo, 8,9,10-hexachlorobornane (B6-923), 2-endo, 3-exo, 5-endo, 6-exo, 8,9,10-heptachlorobornane (B7-1001), and a few minor penta- and hexachloro-CTTs were detected in the samples. The result of the transformation was comparable with observations in naturally contaminated sediments and soil. However, the performance with D. multivorans was more simple and reproducible, as well as faster, than use of soil, sediment, or anaerobic sewage sludge. In agreement with reports in the literature, reductive dechlorination at geminal chlorine atoms (gem-Cls) was found to be the major CTT transformation pathway. Experiments conducted with CTTs and gem-Cls at both primary and secondary carbons clarified that the initial Cl -> H substitution takes place at the secondary carbon C2. Furthermore, the 2-endo-Cl position was preferably substituted with hydrogen. In the case of B8-806, the dechlorination at the secondary carbon C2 was approximately 20-fold faster than the subsequent, slow reduction at the primary carbon C8. The three different formerly unknown heptachloro-CTTs, 2-exo, 3-endo, 6-exo, 8,9,9,10-heptachlorobornane (B7-1473), 2-exo, 3-endo, 6-endo, 8,9,9,10-hepatchlorobornane (B7-1461), and 2-exo, 3-endo, 6-exo, 8,8,9,10-heptachlorobornane (B7-1470) were found as intermediates of the B8-806/809 transformation. Treatment of B9-1679 with D. multivorans indicated that gem-Cls on the bridge (C8 and C9) are dechlorinated faster than gem-Cls on the bridgehead (C10).
Effect of sperm cell density on measured toxicity from the sea urchin Tripneustes gratilla fertilization bioassay
Authors: Vazquez Lourdes C.
Published: November 2004

The sea urchin sperm fertilization bioassay is an approved U.S. Environmental Protection Agency (U.S. EPA) bio-monitoring tool for regulatory and compliance purposes. The method adapted for the Hawaiian species Tripneustes gratilla recommends a sperm-to-egg ratio of 2,500. Using a fixed ratio for all tests does not sufficiently account for seasonal and individual variabilities of this organism. Our studies showed that gametes must be present at specific concentrations, which are unique for each batch. Parallel experiments were conducted to compare tests using a constant 2,500 sperm-to-egg ratio with tests using an optimized sperm dosage determined prior to each analysis. The recommended 2,500 sperm-to-egg ratio often gave overfertilized controls and reduced toxicological response. The risks of oversperming and concomitant toxicity masking were minimized when the bioassays were performed with optimum sperm-to-egg ratio.
Modeling of mixing in internal mixers with long blade tips
Authors: Nassehi V. , Ghoreishy M. H. R.
Published: November 2004

It is well known that blade geometry significantly affects the performance and efficiency of partially filled internal mixers. Intermesh type blades with very long tips are regarded as effective alternatives to almond‐shaped blades used in more traditional tangential rotor mixers. However, using long tip blades results in the formation of long and very narrow sections between the chamber wall and the blade in these mixers. These narrow sections may act as bottlenecks, disrupting flow and mixing of highly viscous compounds in the mixing of elastomers with fillers. Therefore, to avoid costly and time‐consuming trial‐and‐error procedures, the design of long tip blades requires careful quantitative evaluation of their performance. In this article, a computer model, based on the finite element method for the simulation of mixing in twin‐blade intermesh type mixers, is presented. This model represents transient, nonisothermal, non‐Newtonian flow and mixing of a polymer–filler compound in a free surface regime consisting of incompressible and compressible parts. Mixing dependent variations of compound viscosity are also taken into account. To incorporate all of the described realistic aspects of the mixing process in the geometrically complex domain of intermesh type mixers, the developed model is based on a novel and robust solution algorithm. © 2001 John Wiley & Sons, Inc. Adv Polym Techn 20: 132–145, 2001
Leukocyte arylsulfatase A activity in patients with alcohol‐related cirrhosis
Authors: Alvarez‐Leal M. , Contreras‐Hernández D. , Chávez Altagracia , Diaz‐Contreras J.A. , Careaga‐Olivares J. , Zúñiga‐Charles M.A. , Reynoso M.C. , Hernández‐Téllez A.
Published: November 2004

Arylsulfatase (ASA) enzyme deficiency is associated with metachromatic leukodystrophy (MLD), which is a hereditary myelin metabolic disease. It has been proposed that in alcoholic subjects with abnormal ASA, the accumulation of sulfatides may lead to demyelinization and generalized cerebral atrophy. ASA may be diminished in subjects with alcoholic cirrhosis having encephalopathic manifestations. This idea has not been previously proposed. Leukocyte arylsulfatase A (ASA) activity was measured in 30 healthy male volunteers and 28 patients with alcohol‐related cirrhosis. The patients were divided into two groups: patients with alcohol‐related cirrhosis with hepatic encephalopathy history and patients with alcoholic cirrhosis without history of hepatic encephalopathy. Alcoholic cirrhotic patients with history of encephalopathy showed 58.21% (40.95 nmol/mg protein/h) less enzymatic activity than a control group (98.00 nmol/mg protein/h), whereas the group without history of encephalopathy showed an ASA value which was 38.2% (60.55 nmol/mg protein/h) less than the control group. The results suggest that the low ASA activity is a factor associated to the appearance of encephalopathy in patients with alcohol‐related cirrhosis. Am. J. Hum. Biol. 13:297–300, 2001. © 2001 Wiley‐Liss, Inc.
Longitudinal growth study of male Japanese junior high school athletes
Authors: Nariyama K. , Hauspie R.C. , Mino T.
Published: November 2004

The aim of this study was to establish the pattern of adolescent growth in height of male Japanese athletes, and to compare their growth with appropriate controls. The sample consisted of 126 baseball, 39 basketball, 83 soccer, and 53 volleyball players, and 36 nonathletes. The data were collected retrospectively in six public schools in Fukui Prefecture of Western Japan between 1970 and 1987. All subjects were measured at yearly intervals between the age of 6 and 18 years. The total number of measurement occasions for the 337 subjects amounted to 4,134. Athletes trained between 13 and 18 h/week. Individual growth patterns were determined by fitting Preece Baines model I to each individual's serial data. Various biological parameters were derived from the fitted curves. The results indicated that the average growth pattern of these adolescent athletes did not differ substantially from the control group. Volleyball players were significantly taller at 18 years (+3 cm) than the nonathletes (Student's t‐test, P < 0.05). Soccer players showed a slight tendency towards late maturation with age at take‐off and at peak velocity about half a year later than in nonathletes (Student's t‐test, P < 0.05). The 2.3 cm gain in body height due to the later onset of the pubertal growth spurt in soccer players was counterbalanced by a 0.7 cm smaller prepubertal height and a 0.9 cm smaller adolescent gain, so that they ended up slightly, but not significantly, taller than the controls (+0.7 cm). The small differences in growth pattern observed between the nonathletes and the various sports suggest that, in contrast with top‐level athletes, body size and maturation rate were not important selective factors in the various groups of athletes of the present study. Am. J. Hum. Biol. 13:356–364, 2001. © 2001 Wiley‐Liss, Inc.
Adolescent growth events in eight decades of Japanese cohort data: Sex differences
Authors: Ali MD. Ayub , Lestrel Pete E. , Ohtsuki Fumio
Published: November 2004

The presence of secular trends in sex differences for the onset or takeoff of the adolescent growth spurt and subsequent (adolescent) growth of Japanese boys and girls were investigated using data published in “The Statistical Report of the School Health Survey” of the Ministry of Education, Science, Sports and Culture, Japan. An optimum kernel regression method was used to derive the biological parameters of the adolescent growth curve. The six parameters derived from the regression analysis were age at takeoff (ATO), height at takeoff (HTO), velocity at takeoff (VTO), peak height velocity (PHV), age at PHV (APHV), and height at PHV (HPHV). The sex difference in age at PHV is about 2.1 years. The sex difference in age at takeoff was about 2.1 years starting with the birth year of 1943, but has become almost insignificant with the birth year of 1980. After 1960, the sex difference in mean HPHV varied within 12–13 cm, but the difference in HTO showed a decreasing trend. After the birth year of 1911, the rate of growth at HTO for girls has become markedly greater than for boys. In contrast, the rate of growth at HPHV for girls has become significantly smaller than for boys (P < 0.05). Sex differences in ATO, HTO and VTO were significantly and negatively correlated with differences in APHV and HPHV, but positively correlated with the difference in PHV. The sex difference in PHV had no relationship with the differences in APHV and HPHV. Am. J. Hum. Biol. 13:390–397, 2001. © 2001 Wiley‐Liss, Inc.
Age of pubertal onset affects the intensity and duration of pubertal growth peak but not final height
Authors: Vizmanos Barbara , Martí‐Henneberg Carlos , Clivillé Rosa , Moreno Aurelia , Fernández‐Ballart J.
Published: November 2004

This paper analyzed the intensity and duration of height growth during puberty in boys and girls in relation to rhythm of maturation. A longitudinal clinical follow‐up between ages of 10 and 20 years, was carried out in a sample of 251 children grouped according to age at pubertal onset: boys (genital stage 2) at the ages of 11 (n = 28), 12 (n = 38), 13 (n = 42), and 14 (n = 27); and girls (breast stage 2) at the ages of 10 (n = 37), 11 (n = 47), 12 (n = 19), and 13 (n = 13). Height was measured annually. Testicular volume and genital development were assessed in boys, and breast development was assessed in girls. There were significant differences (P < 0.001) in height at the age of pubertal onset among maturity groups. Late maturers were taller than early maturers (r = 0.49, P < 0.001 for girls; r = 0.38, P < 0.001 for boys). However, final heights did not differ according to age of onset in either sex. In boys, later onset of puberty was associated with a smaller pubertal height gain (r = −0.60, P < 0.001) and a shorter period of pubertal growth (r = −0.61, P < 0.001). Equally in girls, earlier onset of puberty was associated with a greater pubertal height gain (r = −0.68, P < 0.001) and a longer period of pubertal growth (r = −0.59, P < 0.001). In conclusion, age of pubertal onset does not affect final height attained in both sexes, since there is an inverse compensatory phenomenon in both sexes between height at pubertal onset and the intensity and duration of pubertal growth. Am. J. Hum. Biol. 13:409–416, 2001. © 2001 Wiley‐Liss, Inc.
New genetic data on Amerindians from the Paraguayan Chaco
Authors: Goicoechea A.S. , Carnese F.R. , Dejean C. , Avena S.A. , Weimer T.A. , Estalote A.C. , Simões M.L.M.S. , Palatnik M. , Salamoni S.P. , Salzano F.M. , Callegari‐Jacques S.M.
Published: November 2004

New data on 17 blood group and protein genetic systems obtained among the Ayoreo and Lengua Indians of Paraguay are presented. They include the first report on the red cell band‐3 protein investigated among South American Indians. This information was integrated with previous results available for these two and four other groups. Five of the six populations reside in the Chaco area, while the sixth was included as an outgroup living elsewhere in Paraguay. Four of the five Chaco tribes exhibit good genetic homogeneity, but the Ayoreo are somewhat different. The results confirm the Chaco as a distinct biological (as well as cultural and economic) region, which should be considered in evaluations of genetic variability among South American Indians. Am. J. Hum. Biol. 13:660–667, 2001. © 2001 Wiley‐Liss, Inc.
Plasma carnitine levels in children with down syndrome
Authors: Seven Mehmet , Cengiz Müjgan , Tüzgen Saffet , İscan >Mehmet Yaşar
Published: November 2004

Carnitine is responsible for several chemical processes, including lipid metabolism, nerve cell conduction, reduction in muscle hypotonia, and limitation in oxidative damage to cells. In patients with Down syndrome (DS), the process of growth is behind that of normal children and neuromuscular control is attained somewhat later. The purpose of this study was to assess variation in levels of carnitine in normal and DS children and the relationship between the amount of carnitine and age. The study involved 30 (15 girls, 15 boys) normal children and 40 (20 girls, 20 boys) DS patients of Turkish ancestry, 6 months to 13 years of age. Carnitine level was determined using Deufel's enzymatic method. Carnitine level was significantly lower in DS patients compared with normal children between 6 months to 5 years of age. Between 5 and 13 years of age, the level of carnitine was about the same in both the normal and DS groups. The results suggest that carnitine level shows a different pattern of age related increase in DS compared to normal children. Am. J. Hum. Biol. 13:721–725, 2001. Published 2001 Wiley‐Liss, Inc.
Brief communication: Neurotraumatological aspects of head injuries resulting from sharp and blunt force in the early medieval period of southwestern Germany
Authors: Weber Jochen , Czarnetzki Alfred
Published: November 2004

Approximately 10% (33 of 304) of the predominantly male skulls from the 6th through 8th centuries in southwestern Germany exhibit cranial fractures derived from blunt or sharp force trauma. No evidence of fracture healing characterizes 24% (n = 8) of these individuals. All nonhealed fractures were caused by sharp force, and four of these wounds cross the sagittal sinus. The lengths of these straight‐edged wounds, produced exclusively by sword blows, measure around 8.0 cm for fatal, and about 5.0 cm for nonfatal wounds. Seventy‐six percent (n = 25) of these skulls exhibit some healing, which indicates that these injuries did not lead to immediate death. In this group are all depressed fractures resulting from blunt force blows. Two thirds of the 45 cranial injuries noted on these 33 skulls are located on the left side of these individuals, with a concentration in the frontoparietal region. Bony indications of wound infection occur in four cases (12%). Three crania exhibit circular trepanations in association with fractures. These phenomena are discussed in the context of modern neurotraumatological knowledge. Am J Phys Anthropol 114:352–356, 2001. © 2001 Wiley‐Liss, Inc.
Adrenoleukodystrophy: Incidence, new mutation rate, and results of extended family screening
Authors: Bezman Lena , Moser Ann B. , Raymond Gerald V. , Piero Rinaldo  , Watkins Paul A. , Smith Kirby D. , Kass Nancy E. , Moser Hugo W.
Published: November 2004

Utilizing the plasma very long chain fatty acid assay, supplemented by mutation analysis and immunofluorescence assay, we determined the number of X‐linked adrenoleukodystrophy (X‐ALD) hemizygotes from the United States identified each year in the two laboratories that perform most of the assays in this country: the Kennedy Krieger Institute between 1981 and 1998 and the Mayo Clinic Rochester from 1996 to 1998. The minimum frequency of hemizygotes identified in the United States is estimated to be 1:42,000 and that of hemizygotes plus heterozygotes 1:16,800. Our studies involved 616 pedigrees with a total of 12,787 identified at‐risk members. Diagnostic assays were performed in 4,169 at‐risk persons (33%) and included members of the extended family. Only 5% of male probands and 1.7% of X‐ALD hemizygotes were found to have new mutations. The extended family testing led to the identification of 594 hemizygotes and 1,270 heterozygotes. Two hundred fifty of the newly identified hemizygotes were asymptomatic and represent the group in which therapy has the greatest chance of success. Identification of heterozygotes provides the opportunity for disease prevention through genetic counseling. Diagnostic tests should be offered to all at‐risk relatives of X‐ALD patients and should include members of the extended family. Ann Neurol 2001;49:512–517
Children with comorbid attention‐deficit‐hyperactivity disorder and tic disorder: Evidence for additive inhibitory deficits within the motor system
Authors: Moll Gunther H. , Heinrich Hartmut , Trott Götz‐Erik , Wirth Sigrun , Bock Nathalie , Rothenberger Aribert
Published: November 2004

For children with attention‐deficit‐hyperactivity disorder (ADHD) or tic disorder (TD), we recently reported deficient inhibitory mechanisms within the motor system by using transcranial magnetic stimulation. These deficits—stated as reduced intracortical inhibition in ADHD and shortened cortical silent period in TD—could be seen as neurophysiological correlates of motor hyperactivity and tics, respectively. To investigate neurophysiological aspects of comorbidity, we measured motor system excitability for the first time also in children with combined ADHD and TD. The findings of a reduced intracortical inhibition as well as a shortened cortical silent period in these comorbid children provide evidence for additive effects at the level of motor system excitability. Ann Neurol 2001;49:393–396