Cellular localization of angiotensin type 1 receptor and angiotensinogen mRNAs in the subfornical organ of the rat brain

The cellular localization of angiotensin type 1 receptor (AT 1) and angiotensinogen mRNA expression in the subfornical organ (SFO) of the rat brain has been studied by means of non-radioactive in situ hybridization combined with immunocytochemistry for glial fibrillary acidic protein (GFAP) and Neutral red staining. The AT 1 receptor mRNA expression is shown to be within putative nerve cells without any association with the glial fibrillary acidic protein (GFAP)-immunoreactive (IR) cells. In contrast the angiotensinogen cRNA expression is associated predominantly with GFAP-IR cells. The results demonstrate that a neuronal AT 1 receptor mediates the actions of circulating angiotensin II on the SFO and that the angiotensinogen mRNA is predominantly expressed in the SFO astroglial cells.     

Engineering embryonic stem cell derived glia for adenosine delivery

Based on the anticonvulsant and neuroprotective properties of adenosine, and based on the long-term survival potential of stem cell derived brain implants, adenosine releasing stem cells may constitute a novel tool for the treatment of epilepsy. Pluripotency and unlimited self-renewal make embryonic stem (ES) cells a particularly versatile donor source for cell transplantation. With the aim to test the feasibility of a stem cell-based delivery system for adenosine, both alleles of adenosine kinase (ADK), the major adenosine-metabolizing enzyme, were disrupted by homologous recombination in ES cells. Adk^−/− ES cells were subjected to a glial differentiation protocol and, as a result, gave rise to proliferating glial precursors, which could be further differentiated into mature astrocytes and oligodendrocytes. Thus, a lack of ADK does not compromise the glial differentiation potential of ES cells. The Adk^−/− ES cells yielded glial populations with an adenosine release of up to 40.1 ± 6.0 ng per 10⁵ cells per hour, an amount considered to be sufficient for seizure suppression. Our findings indicate that Adk^−/− ES cells constitute a potential source for therapeutic adenosine releasing grafts.     

Integrated and sequence-ordered BAC- and YAC-based physical maps for the rat genome

As part of the effort to sequence the genome of Rattus norvegicus, we constructed a physical map comprised of fingerprinted bacterial artificial chromosome (BAC) clones from the CHORI-230 BAC library. These BAC clones provide ~13-fold redundant coverage of the genome and have been assembled into 376 fingerprint contigs. A yeast artificial chromosome (YAC) map was also constructed and aligned with the BAC map via fingerprinted BAC and P1 artificial chromosome clones (PACs) sharing interspersed repetitive sequence markers with the YAC-based physical map. We have annotated 95% of the fingerprint map clones in contigs with coordinates on the version 3.1 rat genome sequence assembly, using BAC-end sequences and in silico mapping methods. These coordinates have allowed anchoring 358 of the 376 fingerprint map contigs onto the sequence assembly. Of these, 324 contigs are anchored to rat genome sequences localized to chromosomes, and 34 contigs are anchored to unlocalized portions of the rat sequence assembly. The remaining 18 contigs, containing 54 clones, still require placement. The fingerprint map is a high-resolution integrative data resource that provides genome-ordered associations among BAC, YAC, and PAC clones and the assembled sequence of the rat genome.     

The measurement of change in endogenous affective disorders

Summary Psychopathological syndromes, as originally revealed by clinical observation, can also be detected by multivariate statistical analyses of symptom ratings. Changes in the course of psychiatric syndromes may be rated simply by improvement scales or by consecutive quantifications of symptoms and their comparison in chronological order. For the latter approach, which is less liable to bias, clinical ratings of psychopathology by staff members, self-ratings by the patients, analyses of patients' overt behavior (including video and speech records), or objective measurements of psychological and/or physiological variables can be used. Advantages and limitations of these different methods are discussed and illustrated by examples from ongoing clinical research in affective disorders. Generally, the combined use of different rating procedures is recommended. Self-ratings are economical, but they may represent aspects of psychopathology other than clinical ratings. In endogenous depression, mood scales are valid (supplementary) tools for the quantification of long-term as well as short-term changes, including diurnal variations. In severe conditions of mania, however, clinical rating has been—until now—the only valid basis for quantifying the degree of psychopathology and its changes with time. Precise evaluation of changes in psychopathology is essential in longitudinal investigations of endogenous affective disorders, since psychopathology up to now seems to have been the most sensitive and the most specific indicator of the hypothetical underlying abnormalities of cerebral functioning.Paper presented at a symposium on The Measurement of Change in Psychopathology at the VI World Congress of Psychiatry, Honolulu, USA, August 1977     

Entwicklung eines Meßinstrumentes zur Bestimmung der Aufmerksamkeit bei Patienten mit cerebralen Läsionen und Funktionsstörungen

Zusammenfassung 58 aufmerksamkeitsgestörte Patienten mit verschiedenen neurologisch-internistischen Grundleiden und 12 Patienten ohne Aufmerksamkeitsstörung wurden untersucht. Ziel der Untersuchung war es, ein standardisiertes Untersuchungsinstrument zur Messung klinisch faßbarer Aufmerksamkeitsstörungen zu erstellen. Es wurde eine additive, 4stufige Skala der Stimulierbarkeit (Guttman-Skala) aus mehreren heterogenen Reizen entwickelt. Auf der anderen Seite wurde eine 4stufige, additive Skala der Reaktivität aus einem Katalog definierter Reaktionen aufgebaut. Mit diesen beiden Skalen wurden Stimulierbarkeit und Reaktivität aufmerksamkeitsgestörter Patienten gemessen. Stimulierbarkeit und Reaktivität der Patienten verhalten sich proportional zueinander. Die Transformation von Stimulierbarkeit in Reaktivität leistet ein internes System, das der gesuchten Aufmerksamkeitsdimension zugeordnet wird.

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Development of a method of measuring the attention of patients with cerebral lesions

Summary 58 patients with various underlying neurological diseases, who had an impairment of attention, were examined. 12 patients without clinically evident disorders of attention were examined as a control group. The aim of the study was the development of a standardized procedure for the assessment of impaired attention. An additive, 4 step scale of the susceptibility to stimulation (Guttman scale) was constructed out of several, heterogeneous stimuli. In addition, an additive 4 step scale of reactivity was constructed out of a catalogue of defined reactions. The two scales permitted the assessment of reactivity and susceptibility to stimulation, the degree of which could be demonstrated as being proportional to one another. The transformation of susceptibility to stimulation into reactivity is thought to be performed by an internal system which is attributed to attention.

     

cAMP-independent responses of olfactory neurons in Xenopus laevis tadpoles and their projection onto olfactory bulb neurons

We report on responses of olfactory receptor neurons (ORNs) upon application of amino acids and forskolin using a novel slice preparation of the olfactory epithelium of Xenopus laevis tadpoles. Responses were measured using the patch-clamp technique. Both amino acids and forskolin proved to be potent stimuli. Interestingly, a number of ORNs that responded to amino acids did not respond to forskolin. This suggests that some amino acids activate transduction pathways other than the well-known cAMP-mediated one. The differential processing of cAMP-mediated stimuli on the one hand and amino acid stimuli on the other was further elucidated by calcium-imaging of olfactory bulb neurons using a novel nose-olfactory bulb preparation of Xenopus laevis tadpoles. The projection pattern of amino acid-sensitive ORNs to olfactory bulb neurons differed markedly from the projection pattern of forskolin-sensitive ORNs. Olfactory bulb neurons activated by amino acids were located laterally compared to those activated by forskolin, and only a small proportion responded to both stimuli. The ensemble of neurons activated by forskolin was also activated by the phosphodiesterase inhibitor 3-isobutyl-1-methylxanthine (IBMX) and the membrane-permeant cAMP analogue 8-(4-chlorophenylthio)adenosine 3',5'-cyclic monophosphate (pCPT-cAMP). We therefore conclude that sensory transduction of a number of amino acids is cAMP independent, and amino acid- and cAMP-mediated responses are processed differentially at the level of the olfactory bulb.     

Cyclic Ladder Polymers by Polycondensation of Silylated Tetrahydroxy‐tetramethylspirobisindane with 1,4‐Dicyanotetrafluorobenzene

Summary: 5,5′,6,6′‐Tetra(trimethylsiloxy)‐4,4,4,4′‐tetramethyl‐1,1‐spirobisindane was polycondensed with 1,4‐dicyanotetrafluorobenzene under variation of solvent temperature, time, and feed ratio. Under optimized reaction conditions, all products detectable by MALDI‐TOF mass spectrometry (up to masses around 8 000 Da) proved to be cyclic ladder oligomers and polymers. In N‐methylpyrrolidone and dimethylsulfoxide odd‐numbered cycles were formed in addition to the prevailing even‐numbered ones. However, in sulfolane exclusively even‐numbered cycles were obtained (detectable up to masses around 10 000 Da), together with even‐numbered linear chains. Temperatures above 100 °C enhanced the molecular weights by side reactions. With the less reactive cyano‐2,3,5,6‐tetrafluorobenzene (CTB) again cycles were formed, but their content and the conversions were lower. Polycondensation of CTB up to 160 °C and all polycondensations of cyanopentafluorobenzene gave crosslinked products.

Synthesis of cyclic ladder polymers.