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The anatomy of co-morbid neuropsychiatric disorders based on cortico-limbic synaptic interactions.

Many brain disorders appear to involve dysfunctions of aminergic systems. Alterations in dopamine activity may underpin both schizophrenia and the establishment and maintenance of drug dependence while disruption of serotonergic signalling may be crucial in both depression and schizophrenia. The co-existence of nicotine and alcohol abuse with depression and schizophrenia is well-documented as is the particular vulnerability of adolescents. At the same time, a common group of brain structures is increasingly implicated in neuropathological studies. For example, depression may involve a lack of serotonin signalling, particularly in the prefrontal cortex, while in schizophrenia there is evidence for reduced dopamine signalling in the same brain region, co-existing with hyperactivity in the mesolimbic dopamine pathway. Increased dopamine release from the mesolimbic dopamine pathway is also a common factor of drugs of abuse. Furthermore, the control of motivational behaviour and dopamine release is apparently modified by hippocampal and amygdala activity, both brain regions showing pathological changes in schizophrenia and depression. Our work has focused on the intricate synaptic interactions of aminergic terminals and cortical and subcortical neurons in order to unravel the anatomical basis for these disorders and their treatments. We show convergence of dopamine and cortical inputs onto single neurons in the nucleus accumbens, and between different cortical inputs to individual neurons, providing a basis for the gating mechanisms attributed to these interactions. We have also examined local and extrinsic connections in the prefrontal cortex and the basis for regulation of both cortical neurons and midbrain dopamine neurons by serotonin from the raph é nucleus. Together with data concerning subcellular receptor distributions, this information provides a detailed synaptic framework for interpreting behavioural, pharmacological and physiological data and enhances our understanding of possible circuitry underlying comorbidity of disorders such as schizophrenia and depression with drug abuse, information invaluable in the introduction of enhanced therapies.

Animals↗

[Female migrants in the health care system. Health care utilisation, access barriers and health promotion strategies].

Due to the evident interaction between social factors and health, migrants are exposed to specific risk factors and access barriers to health services. Some examples are the lower education level, the low social position and/or the insufficient language skills. This concept is further elaborated in the multi-factorial impacts of health literacy. Female migrants often experience additional discrimination because of their gender. Despite the lack of representative data, consistent studies show that female migrants do not regularly take advantage of health care prevention and present themselves with higher degrees of stress. The current "inadequate health care" manifests itself in a lack of care in the areas of prevention and health education and an abundance in the context of medication and diagnostic procedures. To meet these demands and to further reduce barriers, in particular language barriers, specific strategies for this target group involving both politics and the health care system have to be developed. Besides the employment of interpreters with a native cultural background and the distribution of information booklets, it is an important strategy to reduce structural obstacles such as cultural diversity. To contact these women in their living environment should help to increase their self-determined health promotion. Selected models of good practice in Austria with regard to the themes of FGM (female genital mutilation), violence, heart disease and breast cancer are presented to highlight the specific health situation and risk factors of female migrants as well as successful strategies to confront them.

Adolescent↗

[Prevention of melanoma by sun protective measures in childhood. Temporal changes in awareness of parents].

Numerous epidemiological studies on risk factors of malignant melanoma confirm the etiologic role of excessive UV-exposure especially in childhood. Preventive educational campaigns directed to parents of pre-school children have been inaugurated in several countries. In Germany the information was distributed by the "Working group for Preventive Measures in Dermatology" in cooperation with different public health institutions and the media starting in 1993. To evaluate the influence of these efforts on the knowledge and behaviour of the parents, two successive cross-sectional studies at all 56 nursery schools using the same standardised questionnaire were performed. The first interview took place in spring 1993 (before the campaign) with 1341 evaluable questionnaires', the second in fall 1994 (after the campaign) with 1150 evaluable questionnaire. The knowledge of the parents on melanoma risk factors was significantly improved in the second interview. Also the parental behavior regarding sun-protective measures when their children were outdoor at the beach or in the garden definitely changed. In 1993 the best textile sun protection was used by 21% of the parents at the beach and 36% in the garden. These numbers rose to 34% (beach) and 57% (garden) by the second interview. The percentage of children with no sunburn recorded during the preceding summer rose from 39% to 51%. According to the child's gender the parental behavior was different between the sexes; boys were always better protected than girls. The design of this study with two cross-sectional surveys in the same populations does not provide a methodologically sound basis for attributing the observed positive changes to the campaign. Without any doubt it can be stated that the parental knowledge and their attention to sun protection in their children showed substantial improvement in the second survey after the campaign. Thus, these results provide some evidence for the success of the preventive activities and confirm the necessity to continue with such activities.

Child, Preschool↗

Differences in DDT and PCB residues between common and striped dolphins from the southwestern Mediterranean.

Organochlorine concentrations (OCs) and stable isotopes were investigated in the blubber of common dolphins (Delphinus delphis) and striped dolphins (Stenella coeruleoalba) from the southwestern Mediterranean. Samples were obtained from dolphins entangled in fishing nets during the 1992-1994 fishing season and from biopsies taken in 1992. Intrapopulation variations were studied, but because most of the dolphins were juveniles or calves (90%), no significant differences were found on the basis of reproductive condition or sex. Only mature male common dolphins showed significantly higher levels of most of the compounds studied than immature individuals did. There were quantitative and qualitative interspecific differences in organochlorine compounds profile. As compared to common dolphins, striped dolphins carried higher concentrations of organochlorine concentrations (OCs), their %DDE/tDDT and PCB/tDDT ratios were significantly higher, and recalcitrant PCB congeners were more abundant. Distribution and information on composition of stomach contents would in principle support a higher exposure to OCs in common dolphins as compared to striped dolphins, thus apparently contradicting the observed results. However, stable isotopes showed that striped dolphins exploit a higher trophic level, thus explaining observed differences. Interspecific dissimilarities in metabolic capacity to handle OCs may be an added factor. Although in the two species OC concentrations exceeded levels considered to be ineffective in marine mammals, pollution-induced effects on populations could not be properly assessed.

Adipose Tissue↗

Introducing inter-individual growth variability in the assessment of a cephalopod population: application to the English Channel squid Loligo forbesi.

A new approach is presented here to better take into account inter-individual growth variability in age-structured models used for stock assessment. Cohort analysis requires knowledge of the age structure of the catch, generally derived from an age-length key and length-structure information. Age distribution at length is estimated by applying conditional quantile regression to a data set of lengths and ages estimated from calcareous parts. A "stochastic" age-length key that describes the probability of age-at-length is applied to the English Channel squid Loligo forbesi. Age distribution at length from quantile regression proved to be considerably less biased than that resulting from both polymodal decomposition (PD) and two separate slicing methods. Both catch-at-age and stock size were underestimated using classical methods. Estimations of fishing mortalities from classical methods were higher causing underestimation in yield simulations. Quantile regression offers a more complete statistical analysis of the stochastic relationships among random variables than mean regression and PD.

Age Factors↗

A computer program for deriving the rate equations of enzyme catalysed reactions with unbranched mechanisms.

This paper describes a simple program for a desk-top computer which determines the relative concentrations of enzyme-containing intermediates appearing in an enzyme catalysed reaction where the intermediates lie in an unbranched sequence originating and terminating in one enzyme intermediate. This information, the distribution function, then gives the rate equation by the usual means (Wong and Hanes, 1962). The method is rapid and has the advantage that the distribution function may be presented in its complete form or in terms of its dependence on the concentration of the substrates and products. It is also possible to determine the effects of dead-end inhibition.

Computers↗

Selective characteristics of narrative discourse in head-injured and normal adults.

Much controversy surrounds the language production abilities of traumatically head-injured adults. In this study, the narrative skills of head-injured and normal adults are examined and compared on the amount, rate, and distribution of information in a picture description task. The head-injured adults, all of whom were at least six months postinjury, were found to be similar to the normals in the amount of pertinent content expressed, narrative length, and rate of speech in the given narrative task; however, they were found to be significantly slower in the rate of information imparted. This decreased efficiency of communication was related to the head-injured adults' lengthier and slower verbal outputs. They required relatively more words and time to convey the essential information. Finally, several clinical implications are raised concerning the use of narrative tasks in head-injured rehabilitation.

Adolescent↗

A human skin window technique using micropore membranes.

A skin window technique using micropore membranes is described. Eight micrometre pore-size membranes are placed on abrasions made with a dental stone and covered with moist filter paper and impermeable film: adhesive tape is placed overall. The assembly is unobtrusive and stable and may be worn during normal activities. For clinical studies, a series of membranes used over 4-5 h gives information on distribution of leucocyte emigration sites, numbers and types of emigrant cells, their rate of locomotion in the membrane (solely under the influence of endogenous factors) and any difference in form, surface phenotype or function between cells at the dermal surface and those which have traversed the membrane. This system, using a 3-dimensional labyrinthine structured membrane, avoids errors inherent in previous techniques, e.g., differential adhesiveness, competition for space, no quantification of locomotion after emergence or indication of the productive area of the abrasion. Incidental findings include no major change in the nature of the emigrating population over 24 h, the presence of monocytoid cells from the earliest phase in normal subjects, the origin of emigrating cells in discrete foci, and an even distribution of cells in a fully infiltrated membrane. The skin window technique is capable of greater clinical precision and experimental elaboration than hitherto realised.

Cell Movement↗

Spiders in Brazil.

Descriptions of the principal venomous spiders in Brazil, of the genera Phoneutria, Loxosceles, Latrodectus and Scaptocosa, are given, together with a list of species and their geographical distribution. Detailed information on their habitat, behaviour and venom quantity, symptomatology of human accidents and epidemiology is given and recommendations are made for the prevention of accidents. General observations are made on the most common mygalomorph spiders.

Animals↗

Data dissemination for the population census.

"Recent developments in the data-dissemination system for census of population statistics are reviewed, with particular reference to Great Britain. Key issues discussed include: the expansion of census output and the need for summaries of census results; the significance of consultation with census users; the development and functions of guides for census users; the emergence of data-dissemination centres and archives offering new services; the functions of area typologies as a new type of census by-product; the demand for Public Use Samples and the problem of confidentiality; and the emergence of large-scale surveys as alternatives to the census."

Censuses↗

The projection from the motor cortex to the inferior olive in the cat. An experimental study using axonal transport techniques.

The cortico-olivary projection has been investigated in the cat with the methods of retrograde transport of horseradish peroxidase and wheat-germ agglutinin conjugated with horseradish peroxidase as well as autoradiographic techniques using tritium-labelled amino acids. The projection arises from cells in cortical layer V and terminates mainly ipsilaterally and less densely contralaterally. The strongest termination site is in the caudal medial accessory olive adjacent to subnucleus beta. Projections to that area originate in the medial portions of areas 4 and 6 rostral to the cruciate sulcus. Regions of the motor cortex related to axial back and neck, proximal forelimb and face musculature plus the frontal eye field are represented in largely overlapping areas of the caudal medial accessory olive. A second zone of termination is present in the rostral olive at the junction of the ventral lamella of the principal olive and the medial border of the dorsal accessory olive. Projections to that area arise from a central portion of area 4 at the border between the anterior sigmoid gyrus and the presylvian gyrus. This area contains portions of the representation of the muscle groups controlling the neck and proximal forelimb (shoulder and elbow) only. The frontal eye field, which in the cat influences both extraocular and neck musculature, is also an important direct source of input to this portion of the inferior olive. Contralateral terminations are distributed symmetrically. Combining this information with the olivocerebellar distribution, cerebellar cortical areas corresponding to this direct cortical input are defined. Taking into account that the cortico-olivary fibers appear to arise only from those portions of the motor cortex involved in the control of axial and proximal forelimb muscles, it is suggested that the cortico-olivo-cerebellar projections play a preponderant role in the cerebellar control of posture.

Animals↗

Spinal lamina I projection neurons in the rat: collateral innervation of parabrachial area and thalamus.

A major ascending nociceptive pathway from spinal lamina I to the mesencephalon has previously been reported in the cat, rat and monkey. In the present paper, we have used single and double retrograde labeling techniques to describe this projection system and its collateralization to the thalamus in the rat. Injections of wheat germ agglutinin-horseradish peroxidase into the pontomesencephalic parabrachial area labeled cell bodies bilaterally in lamina I and deeper laminae of the spinal cord. Bilateral lesions of the dorsolateral funiculi at thoracic levels reduced labeling of lamina I neurons caudal to the lesions. Combined injections of fluorescent retrograde tracers into the lateral thalamus and parabrachial area resulted in double labeling of projection neurons in lamina I, lamina IV VIII and the lateral spinal nucleus of the cervical and lumbar enlargements. Double-labeled neurons were especially abundant in lamina I. Thus, we have demonstrated a major lamina I projection through the dorsolateral funiculi to the parabrachial area with significant collateralization to the thalamus. Moreover, since more than 80% of retrogradely labeled lamina I spinothalamic tract cells had collaterals to the parabrachial area we have indirectly demonstrated the presence of a dorsolateral funicular pathway for lamina I spinothalamic neurons in the rat. More lamina I neurons were retrogradely labeled from midbrain injections as compared to thalamic injections. The significance of these findings rest on previous work in this and other laboratories and concerns the understanding of spinal nociceptive mechanisms. Lamina I projection neurons are primarily nociceptive-specific in their response properties and have been shown to project to both the midbrain and thalamus via the dorsolateral funiculus in a number of species. The role of this projection system in nociceptive transmission may lie in its ability to distribute precise information to multiple brain stem sites which in turn activate autonomic or affective responses or descending pain modulatory mechanisms.

Animals↗

Perception of words and non-words in the upper and lower visual fields.

The findings of previous investigations into word perception in the upper and the lower visual field (VF) are variable and may have incurred non-perceptual biases caused by the asymmetric distribution of information within a word, an advantage for saccadic eye-movements to targets in the upper VF and the possibility that stimuli were not projected to the correct retinal locations. The present study used the Reicher-Wheeler task and an eye-tracker to show that, using stringent methodology, a right over left VF advantage is observed for word recognition, but that no differences were found between the upper and the lower VF for either word or non-word recognition. The results are discussed in terms of the neuroanatomy and perceptual abilities of the upper and the lower VF and implications for other studies of letter-string perception in the upper and the lower VF are presented.

Analysis of Variance↗

She2p is a novel RNA binding protein with a basic helical hairpin motif.

Selective transport of mRNAs in ribonucleoprotein particles (mRNP) ensures asymmetric distribution of information within and among eukaryotic cells. Actin-dependent transport of ASH1 mRNA in yeast represents one of the best-characterized examples of mRNP translocation. Formation of the ASH1 mRNP requires recognition of zip code elements by the RNA binding protein She2p. We determined the X-ray structure of She2p at 1.95 A resolution. She2p is a member of a previously unknown class of nucleic acid binding proteins, composed of a single globular domain with a five alpha helix bundle that forms a symmetric homodimer. After demonstrating potent, dimer-dependent RNA binding in vitro, we mapped the RNA binding surface of She2p to a basic helical hairpin in vitro and in vivo and present a mechanism for mRNA-dependent initiation of ASH1 mRNP complex assembly.

Amino Acid Sequence↗

Characterization of stable aluminium-citrate species as reference substances for aluminium speciation by ion chromatography.

Well-defined anionic aluminium-citrate species are accessible from crystalline aluminium complexes. The solution chemistry of those species can be investigated using ion chromatography as a powerful tool for aluminium speciation in aqueous samples. The separation of three anionic aluminium-citrate complexes by anion exchange chromatography is possible within 5 min using isocratic conditions. The element specific detection was done by online coupled ICP-AES. The remaining charge of the complexes after dissolution can be determined by ion chromatography using a retention model. Time-dependent monitoring of the species distribution gave information about the species stabilities and the decomposition pathways. With citric acid as an aluminium chelator partially very stable anionic species are observed. These complexes are important components in biological systems. An example for the practical use of the separation method and the well-defined standards is given for plant sap, which showed two species with similar behavior compared to the investigated stable aluminium-citrate complexes.

Aluminum↗

New drugs of abuse in North America.

The term "drugs of abuse" usually brings to mind traditional street drugs, such as cocaine, heroin, marijuana, and methamphetamine. The drug scene, however, is constantly evolving. As various law enforcement agencies pursue and dismantle distribution and pro-duction organizations of the usual drugs of abuse, dealers and users are turning to less known, more accessible, and often currently licit substances. The widespread growth of the Internet with its vast distribution of information has increased the accessibility ofa host of substances and facilitated synthesis and production of various substances by individuals. This article discusses several new and emerging abused substances, including new synthetic variations, plants, and pharmaceuticals diverted for abuse.

Humans↗