All-perylene-derivative for white light emitting diodes.

An organic-based bright white light emitting compound, namely Tb(H3PTC)3 [H4PTC = perylene-3,4,9,10-tetracarboxylic acid], able to be used as part of a white diode and as a part of a RGB system that can withstand high temperatures (∼700 K), is developed using perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA) and terbium(iii) nitrate pentahydrate as precursors by hydrothermal synthesis. Using PTCDA as the red emitter and the new derivative of it, Tb(H3PTC)3, as the blue-green emitter, along with a common deep blue LED can form a RGB system for display technologies, around room temperature. Temperature-dependent photoluminescence properties of the Tb(H3PTC)3 compound are also investigated for the involved excitonic-emission processes and the respective recombination lifetimes. The terbium(iii) complex was prepared using a procedure that is reproducible, easily modifiable, inexpensive, and environmentally friendly, opening new pathways for its large-scale applications. Unlike PTCDA, Tb(H3PTC)3 has been shown to be soluble in N-methyl-2-pyrrolidone (NMP) as well as in dilute aqueous solutions of this organic solvent in a straightforward procedure. The light emission properties are intimately correlated with the molecular structure and electronic properties of Tb(H3PTC)3 elucidated by experimental results of X-ray Absorption Near Edge Spectroscopy (XANES), Extended X-ray Absorption Fine Structure (EXAFS) and Density Functional Theory (DFT) calculations. A bright fluorescence yield is attained with a small amount of material either in solution or in solid form showing its potential to be used in state-of-the-art organic optoelectronic devices.

[Pharmaokinetics of beta-escin after administration of various Aesculus extract containing formulations]. / Pharmakokinetik von beta-Aescin nach Gabe verschiedener Aesculus-Extrakt enthaltender Formulierungen.

With a specific radioimmunoassay the pharmacokinetics and relative bioavailability of escin was measured after administration of different formulations containing Aesculus-extract. Of special interest was the relative bioavailability of escin after administration of a newly developed film-coated tablet with sustained release in comparison to a reference formulation. In a cross-over steady-state study in 24 volunteers bioequivalence of test and reference preparation could be demonstrated. The 90% confidence interval of the AUC (O-tau) was 98.3 to 120.9%.

Responses of single neurons in amygdala to interoceptive and exteroceptive stimuli in conscious cats.

The amygdala is critical for behavioral arousal and must therefore integrate a wide variety of inputs. We examined sensory inputs and the degree of convergence to single neurons in the amygdala in conscious freely moving cats. A pressor stimulus elicited responses, predominantly inhibitory, in one-half of the amygdalar neurons tested. Most neurons in the central and basal nuclei responded to carotid chemoreceptor activation typically with an excitation. Almost one-half of all amygdalar neurons tested, particularly in the central nucleus, received orthodromic input from the locus ceruleus, the substantia nigra, and/or the contralateral central nucleus of the amygdala. Exteroceptive sensory stimulation with optic, acoustic, tactile, and olfactory stimuli elicited responses in 33, 55, 39, and 59% of amygdalar neurons, respectively. Two-thirds of the neurons tested with more than one external stimulus modality responded in the same manner to the various stimuli (usually excitation), demonstrating a convergence of exteroceptive stimuli on single amygdalar neurons, particularly in the basal nucleus. Spontaneous and induced behavioral arousal elicited responses in 92 and 86% of neurons, respectively. Most neurons responded to multimodal exteroceptive stimuli and behavioral arousal in the same manner. We suggest that amygdalar inputs are highly varied and, in many cases, relatively nonspecific and that the amygdala integrates a large number of external and internal sensory modalities to regulate autonomic and behavioral responsiveness to various stimuli.

The DNA binding activity of the liver transcription factors LFB1 (HNF1) and HNF4 varies coordinately in rat hepatocellular carcinoma.

As renal cell carcinomas are characterized by the disappearance of the transcription factor LFB1, which is known to be primarily involved in gene regulation in the liver, we have measured the presence of LFB1 in rat hepatocellular carcinomas induced by diethylnitrosamine. The level of LFB1 binding activity in adenoid-cystic as well as trabecular tumours shows some variation and may either be lower or higher than in the non-tumorous tissue. The amount of LFB1 binding activity correlates with the binding activity of HNF4, a transcription factor reported to stimulate LFB1 expression. As the levels of LFB1 and HNF4 binding activity differ extensively in various hepatocellular carcinomas, it is unlikely that these transcription factors play a general role in hepatocarcinogenesis. This is in contrast to renal carcinogenesis where a dramatic loss of LFB1 is a consistent feature.

Overexpression of glucose-6-phosphate-dehydrogenase in rat hepatic preneoplasia and neoplasia.

Abundance of messenger RNA (mRNA) and activity of glucose-6-phosphate dehydrogenase (G6PDH), the rate limiting enzyme of the oxidative pentose phosphate pathway, were studied in preneoplastic foci of altered hepatocytes (FAH) and hepatocellular carcinomas (HCC) induced in rats by limited oral exposure to N-nitrosomorpholine (NNM-stop model). Northern blot analysis revealed increased amounts of G6PDH-mRNA in 9/10 HCC, which are apparently not due to structural alterations of the G6PDH gene as studied by Southern blot analysis. In four additional HCC elevated expression of G6PDH was demonstrated by in situ hybridization to antisense-mRNA and by catalytic enzyme histochemistry. This correlative molecular genetic and enzyme histochemical approach was also used to study G6PDH expression in FAH of different phenotypes, namely glycogen storage foci (GSF), mixed cell foci (MCF) acid basophilic cell foci (BCF), representing early (GSF) and advanced (MCF, BCF) stages of hepatic preneoplasia. mRNA level and activity of G6PDH were closely correlated in all types of lesions and increased from GSF to MCF/BCF and HCC. These results suggest a predominantly transcriptional regulation of the increasing expression of G6PDH during hepatocarcinogenesis in the rat.

Performance factors and gender-related differences in spatial ability: another assessment.

To explore whether test-taking styles (performance factors) can contribute to explaining gender-related differences on tests of spatial ability, 15 spatial tests were administered to three samples of subjects. On each test, number-correct scores and ratio scores (number of items solved divided by the number of items attempted) were computed. In accordance with previous research findings, the use of ratio scores significantly reduced the magnitude of the gender-related differences on the Mental Rotations Test. For most of the remaining tests, however, the reduction of the gender-related score difference was small. It was concluded that the difference reduction for the Mental Rotations Test was specific to the format of this test. In common spatial tests, performance factors may account for a small portion of gender-related variance, but the bulk of this variance must be attributed to other factors.

A molecular-based magnet with a fully interlocked three-dimensional structure.

A compound has been synthesized with the formula (rad)(2)Mn(2)[Cu(opba)](3)(DMSO)(2).2H(2)O, where rad(+) is 2-(4-N-methylpyridinium)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide, opba is orthophenylenebis(oxamato), and DMSO is dimethyl sulfoxide. It consists of two nearly perpendicular graphite-like networks with edge-sharing Mn(II)(6)Cu(II)(6) hexagons. The two networks are fully interlocked with the same topological relationship as that between adjacent rings of a necklace. The compound has three kinds of spin carriers: Mn(II) and Cu(II) ions, antiferromagnetically coupled through oxamato bridges, and rad(+) radical cations, bridging the Cu(II) ions through the nitronyl nitroxide groups and forming Cu-rad chains. The temperature dependence of the magnetization reveals that below 22.5 K, the compound behaves as a magnet.

Cellular and molecular mechanisms of renal carcinogenesis induced by avian erythroblastosis virus.

Besides erythroleukemias and sarcomas, avian erythroblastosis virus strain ES4 (AEV-ES4) induces renal adenocarcinomas (RCas) in chickens. To search for the cells of origin and the mechanism of the development of RCas, we investigated the RCas produced by td359AEV, a mutant of AEV-ES4 which lacks a leukemogenic effect, but which is sarcomagenic. Spindle cell sarcomas in various organs and RCas developed in a high number of chickens inoculated with td359AEV. RCas were tubulo-cystopapillary structures of basophilic cells and originated only from differentiated principal cells (PCs) of the renal collecting duct system. The origin of tumors from PCs was indicated by connections of tumor epithelium to segments of the collecting duct system, including connecting tubules and cortical and medullary collecting ducts. Tumor cells showed typical mucopolysaccharide-containing vacuoles which are characteristic of chicken PCs. Viral particles were observed throughout the kidney. Moreover, the highest numbers of particles as well as budding-images of them were seen (apart from tumor cells) in podocytes and distal tubule cells which did not undergo neoplastic change. The susceptibility of PCs to undergo neoplastic transformation could not be related to a particular activation state of the erbB gene, in view of the fact that cerbB expression was detected by in situ hybridization in the epithelium lining the Bowmann's capsule and the entire renal tubule system. From data of Northern blot and in situ hybridization techniques, it was suggested that the neoplastic transformation of PCs was elicited by overexpression of the v-erbB oncogene, a feature of tumor cells already detected in renal tubules lined by basophilic proliferating cells, the first stages of renal carcinogenesis induced by td359AEV. According to Southern blot analysis, td359AEV proviruses were randomly inserted in tumor DNAs and the RCas were polyclonal in nature.

Altered transferrin gene expression in preneoplastic and neoplastic liver lesions induced in rats with N-nitrosomorpholine.

The expression of the gene for the iron transport protein transferrin was found to be altered in preneoplastic and neoplastic lesions induced in the rat liver by N-nitrosomorpholine. The total RNA of ten hepatocellular carcinomas (HCC) was investigated by Northern blot analysis using a cDNA-probe comprising 150 bp of the 3' region and compared with the total hepatic RNA in untreated rats. Seven hepatocellular carcinomas showed slight or pronounced reduction in transferrin expression. In situ hybridization of two additional hepatocellular carcinomas revealed marked reduction in the mRNA level for the transferrin gene compared with the surrounding tissue. In contrast, the majority of early preneoplastic lesions storing excess glycogen and tigroid cell foci expressed increased levels of transferrin mRNA. The loss of glycogen in mixed cell foci, which represent a later stage of hepatocarcinogenesis, was usually accompanied by a decrease in transferrin mRNA suggesting a close relationship between this change in gene expression and cellular dedifferentiation emerging during hepatocarcinogenesis.

Dietary fructose enhances the development of atypical acinar cell nodules in the pancreas of rats pretreated with N-nitrosomorpholine.

Dietary influences on carcinogenesis have been shown in various tissues on the basis of epidemiological and experimental approaches. The present paper demonstrates that the oral application of fructose over long periods to rats previously treated with N-nitrosomorpholine increases the incidence of atypical acinar cell nodules (AACN) in the pancreas. Whereas an increase in AACN was statistically significant (P less than 0.005), no effect on ductule-like structures was detectable. AACN have been regarded as precursor lesions of the acinar cell carcinoma. Although the AACN observed frequently exhibited severe atypia and numerous mitotic figures, no clearcut evidence for malignancy could be detected under our experimental conditions.

Afferent connections of the nucleus centralis amygdalae. A horseradish peroxidase study and literature survey.

The central nucleus of the amygdala has been shown to be involved in cardiovascular regulation and the integration of arousal. In this study, the afferent input was investigated in cat by microinjecting horseradish peroxidase (HRP) into the central nucleus and examining retrogradely-labelled cells in the brain. Retrograde labelling was found in the cortex next to the sulcus ectosylvius anterior, fissura lateralis Sylvii, sulcus rhinicus anterior and posterior, sulcus suprasylvius, and pyriform and entorhinal cortices as well as in the insula and claustrum. Each of the sub-nuclei of the amygdaloid complex exhibited retrogradely-labelled perikarya. Labelled cells were also found in the diagonal band of Broca, nucl. lateralis septi, and nucl. proprius striae terminalis (bed nucl. of stria terminalis). In the hypothalamus the area preoptica medialis and lateralis, nucl. dorsomedialis, paraventricularis, periventricularis, arcuatus and mammilaris medialis were labelled. The nucl. subthalamicus, zona incerta, peripeduncular system, substantia nigra, and nucl. interpeduncularis contained HRP-marked cells. In the thalamus labelled cells were observed in the nucl. reuniens, nucl. centroposterior lateralis, nucl. latero-posterior, nucl. posterior, nucl. centro-anterior, antero-dorsalis, antero-medialis, antero-lateralis, centrum mdianum, nucl. reticularis, nucl. rhomboideus, nucl. parafascicularis and subfascicularis. The area tegmentalis Tsai and the corpora geniculata also contained labelled cells. In the brain stem, HRP-marked cells could be detected in the brachium colliculi inferioris, aqueductal grey matter, locus coeruleus, nucl. parabrachialis, in various nuclei of the formatio reticularis, in the nucl. retrofascialis, nucl. solitarius, nucl. commissuralis, nucl. ambiguus and nucl. dorsalis n. vagi. The results were compared to other neuroanatomical studies and to functional studies of the amygdala.

Sex-related differences in spatial ability: more evidence for convergence.

Sex-related differences in spatial ability, favoring males, have frequently been reported in the literature. Recent analyses, however, have found indications of a convergence in the scores of men and women on spatial tests over the years. This research examined the evidence for such a secular trend in a German population using data of 18 samples that had completed the Cube Perspectives Test, a measure of spatial visualization ability. The largest effect size (d = .77) was found for a sample tested in 1978, the smallest difference (d = .38) was observed for a sample tested in 1987. There was a clear trend narrowing the sex-related differences; the correlation between the recency of the data and the respective d-value was -.926. The convergence of the scores of men and women proved to be stronger than in the previous studies.

Sensory input to single neurons in the amygdala of the cat.

We determined functionally the afferent projections from exteroceptors and enteroceptors (visceral receptors) to single cells of the amygdala. Recordings were made in chloralosed cats from 249 cells in four subnuclei of the amygdala. Forty-six percent of cells tested responded to carotid sinus nerve stimulation and more than one-half of them responded to selective baroreceptor or chemoreceptor activation or to electrical stimulation of the locus ceruleus. Of 11 cells responding similarly (inhibition) to carotid sinus nerve stimulation and to selective baroreceptor activation, all were inhibited by locus ceruleus stimulation, also. Approximately 17% of cells tested responded to at least one exteroceptive stimulus (acoustic, optic, or tactile) whereas 14% responded to more than one exteroceptive stimulus in a similar manner. Amygdalar cells were also identified that responded to visceral (renal nerve) and somatic (iliac nerve) stimulation. Many cells received input both from enteroreceptors and from exteroceptors. These results suggest that baroreceptor input to single neurons in the amygdala is often convergent with input from the locus ceruleus. In addition, the convergence of both internal and external sensory inputs to single neurons is further evidence that the amygdala is a site for the integration of responses to arousal.

Baroreceptor sensitivity during desynchronized sleep.

Sleep is characterized by periods of cortical and subcortical desynchronization similar to that observed during arousal. Because baroreflex control of heart rate is suppressed in the aroused state, the present study compared the cardiac index of baroreflex sensitivity in awake cats with that during desynchronized sleep to determine the level of arousal and its affect on autonomic regulation. Cats were prepared for long-term arterial pressure, cortical, and subcortical EEG and EMG recording. After acclimatization to the laboratory, cats engaged in spontaneous periods of desynchronized sleep. During this period, a bolus of angiotensin II was injected i.v. and the subsequent change in the R-R interval of the cardiac cycle was recorded during the rising phase of the pressor response. These values were compared with values obtained from the same cats during quiet and active wakefulness and those obtained during drug-induced desynchronized sleep with gamma-hydroxybutyrate. The values obtained during naturally occurring desynchronized sleep were comparable to those observed during drug-induced desynchronized sleep. In contrast, the increase in the R-R interval in awake cats, particularly quiet ones, was greater than that seen during desynchronized sleep or during active periods in the awake animal. These data suggest that there is a correlation between the level of arousal, as measured by EEG activity, and the cardiomotor component of baroreflexes.

[Computed tomography in follow-up of differentiated thyroid carcinoma]. / Computertomographie in der Nachsorge des differenzierten Schilddrüsenkarzinoms.

The importance of computed tomography in follow-up aftercare and therapy planning in differentiated carcinoma of the thyroid is examined on the basis of the authors' experiences in a group of about 600 patients. The individual indication ranges are discussed and demonstrated by means of examples.

[Long-term observation of 15 patients with differentiated thyroid cancer and elevated plasma thyroglobulin levels of unclear origin]. / Langzeitbeobachtung bei 15 Patienten mit differenziertem Schilddrüsenkarzinom und unklar erhöhten Plasmathyreoglobulinspiegeln (Tg).

The follow-up of 15 patients with differentiated cancer of the thyroid was analysed retrospectively. All patients had persistent or developed elevated thyroglobulin (Tg) plasma levels (greater than 10 ng/ml) after total thyroidectomy and 131 I therapy. There was no evidence of thyroid remnants or metastases in the 131 I whole body scan, bone scan, chest X-ray or clinical investigation. Nine of 15 patients developed local or distant metastases during a follow-up period of 3-39 months (mean = 18 months). Only one of seven recurrences tested were 131 I positive, Tg values of 9 from 12 patients showed no correlation to the Thyroid-stimulating hormone (TSH) level. It is concluded that: (1) this group of patients is at high risk of developing a recurrence (2) new methods have to be developed for the localization of 131 I negative but Tg positive metastases.

Baroreceptor reflex during arousal induced by electrical stimulation of the amygdala or by natural stimuli.

Baroreceptor control of heart rate was studied in 14 unanaesthetized cats during rest and arousal induced by either electrical stimulation of the central nucleus of the amygdala or by natural stimuli. The baroreceptor reflex was elicited by i.v. injections of angiotensin II and the sensitivity of the vagal component of the reflex expressed as the regression coefficient of the relationship between the systolic blood pressures of successive arterial pulses and their pulse intervals. Baroreceptor reflex sensitivity was reduced by all types of arousing procedure studied; an effect assumed to be a part of integrated cardiovascular adjustments accompanying arousal. Further studies in slightly anaesthetized cats were performed in order to investigate the time-course of such changes in reflex sensitivity. Th inhibition of the vagal component of the reflex did not last for the entire period of the electrically elicited arousal and it is suggested, therefore, that this might reflect the activation of mechanisms which limit orienting behaviour. Overall, these results indicate that the central nucleus of the amygdala may be involved in a transient integration of cardiovascular and behavioural responses during arousal.