Showing papers by "University of Kiel published in 1990"

Activation of unmyelinated afferent fibres by mechanical stimuli and inflammation of the urinary bladder in the cat.

Abstract: 1. We examined the functional properties of unmyelinated primary afferent neurones innervating the pelvic viscera in twenty-five anaesthetized cats. The axons were isolated from the intact dorsal root and the intact or chronically de-efferented ventral root of the segment S2. All units were electrically identified with electrical stimulation of the pelvic nerve. 2. The responses of the neurones were studied with natural stimulation of the urinary bladder using innocuous and noxious increases of intravesical pressure and at the onset of an acute artificial inflammation induced by intraluminal injection of mustard or turpentine oil. 3. Out of 297 unmyelinated afferent units isolated from the dorsal root, seven were excited by an increase of the intravesical pressure during contractions and distension of the urinary bladder. These units were silent when the bladder was empty and had thresholds of 30-50 mmHg which are presumed to be noxious. Further increases of the intravesical pressure were accurately encoded by the discharge rate of the fibres. Out of sixty-eight unmyelinated afferent units isolated from the ventral root none was activated by these stimuli. 4. Intraluminal injection of mustard oil excited mechanosensitive units at short latency. The discharge was not closely related to changes of the intravesical pressure and the units displayed on-going activity after the irritant had been removed. This observation suggests that the units had also chemosensitive properties and that the receptive endings were located in the bladder wall. 5. In sixteen cats ninety-five afferent fibres that were not activated by noxious mechanical stimuli of the urinary bladder were systematically tested with intraluminal injections of mustard oil. This excited 7/67 dorsal root units and 4/28 ventral root units with short latency. Intraluminal application of turpentine oil, tested on twenty-six afferents in four animals, did not produce a rapid excitation. 6. Following the induction of an inflammation some previously non-mechanosensitive units started to respond to changes of intravesical pressure in the biologically relevant pressure range of the urinary bladder. 7. In conclusion, a small subpopulation (2.4%) of unmyelinated visceral afferents responds to high, presumably noxious, intravesical pressure and intraluminal application of chemical irritants. Acute inflammation excites a larger proportion of afferents (9.5%) that are not activated by acute noxious mechanical stimulation of the normal urinary bladder. In the inflamed bladder some previously non-mechanosensitive units started to respond to increases of intravesical pressure. These novel types of chemosensitive receptors may contribute considerably to the pathogenesis of visceral pain states.

Automata on Infinite Objects.

Abstract: Publisher Summary This chapter focuses on finite automata on infinite sequences and infinite trees. The chapter discusses the complexity of the complementation process and the equivalence test. Deterministic Muller automata and nondeterministic Buchi automata are equivalent in recognition power. Any nonempty Rabin recognizable set contains a regular tree and shows that the emptiness problem for Rabin tree automata is decidable. The chapter discusses the formulation of two interesting generalizations of Rabin's Tree Theorem and presents some remarks on the undecidable extensions of the monadic theory of the binary tree. A short overview of the work that studies the fine structure of the class of Rabin recognizable sets of trees is also presented in the chapter. Depending on the formalism in which tree properties are classified, the results fall in three categories: monadic second-order logic, tree automata, and fixed-point calculi.

What happens to zooplankton faecal pellets? Implications for material flux

Abstract: Copepod faecal pellets have often been considered as rapid transporters of material out of the euphotic zone. Laboratory experiments on their degradation and sinking rates support this view, but field data on the distribution and flux of pellets through the water colomn present contradictory evidence. We suggest that due to the exclusion of metazoans from previously published degradation experiments, such studies may have little relevance to the natural environments. In 1987/1988 we carried out experiments using adult copepods of mixed species but dominated byCentropages hamatus collected in Kiel Bight (FRG). We have demonstrated that copepods can be highly adept at breaking up their own pellets while ingesting only a small proportion, a behaviour we define as “coprorhexy”. The microbiota is probably unable to cause significant modification to faecal pellets before they are fragmented within a few hours of their production. Thereafter, microbial remineralisation will become important. Many of the “difficult” field data can be readily explained if the process of coprorhexy is taken into account and, indeed, breakage of large particles by crustacean zooplankton may be an important process in modifying material transport in the ocean. Copepods appear to perform coprorhexy by removing the peritrophic membrane with its attached bacterial flora and this may then be ingested. We speculate on the nutritional value of such a behaviour and the possible significance of “ghost” pellets, consisting of a membrane with little or no apparent solid content.

Primary lymphomas of the lung morphological immunohistochemical and clinical features

Abstract: Sixty-two cases of primary malignant lymphoma of the lung were investigated. Fifty-eight lymphomas were of B- and two of T-cell type. Two cases of high-grade lymphoma could not be further classified. The largest group (43 cases) consisted of low-grade B-cell lymphoma of the bronchus-associated lymphoid tissue. These showed features similar to low-grade B-cell lymphomas of the mucosa-associated lymphoid tissue of the stomach. The low-grade lymphomas showed a peak occurrence in the sixth decade, the high-grade lymphomas in the seventh decade. Males predominated slightly. Three-quarters of the patients with low-grade B-cell lymphoma of the bronchus-associated lymphoid tissue showed solitary or multiple sharply defined nodules of the lung. The prognosis of the B-cell-derived lung lymphomas without constitutional symptoms was relatively favourable, regardless of whether they were of low- or high-grade malignancy, whereas patients with constitutional symptoms and the two patients with T-cell lymphomas showed a bad prognosis. However, recurrences and metastases in the lung, stomach, lymph nodes and salivary glands were seen in about 46% of the cases of low-grade B-cell lymphoma of the bronchus-associated lymphoid tissue.

Segmental Reduction in Connected Speech in German: Phonological Facts and Phonetic Explanations

Abstract: This paper deals with /r/ vocalization, weak forms, elisions and assimilations in connected speech in German and provides phonological rules within the generative framework for the derivation of any observable reduction forms, given certain phonetic environments. Some syntactic constraints are also discussed. This phonological description is then supplemented by an enquiry into the production and perception constraints of real speakers and real listeners to find answers to the questions as to why certain articulatory modifications occur and others do not, and why they take particular directions. This phonetic explanation is sought in a minimization of energy expenditure in relation to the perceptual demands of the communicative situation.

Diurnal salivary cortisol patterns during pregnancy and after delivery: relationship to plasma corticotrophin-releasing-hormone.

Abstract: The circadian rhythm of salivary cortisol was studied in 10 healthy women every 4 weeks throughout pregnancy. In addition, in 12 women the diurnal patterns of salivary cortisol, serum cortisol, plasma ACTH, plasma CRH and serum progesterone were analysed in late third trimester pregnancy and again 3-5 days after delivery. Salivary cortisol profiles exhibited a clear circadian rhythm during pregnancy with an increase in mean salivary cortisol from the 25th to 28th week onwards reaching concentrations in late pregnancy more than twice as high as in non-pregnant controls, rapidly returning to normal concentrations after delivery. The coefficient of variation of salivary cortisol profiles decreased in third trimester pregnancy due to a parallel upward shift of cortisol concentrations (40.2 +/- 3.4% vs 77.6 +/- 6.6% after delivery, P less than 0.01). A diurnal pattern was also found for plasma ACTH and serum cortisol before and after delivery with lower concentrations post-partum (P less than 0.01). In late pregnancy, progesterone concentrations were significantly higher in the evening (930 +/- 85 nmol/l vs 813 +/- 74 nmol/l at 0900 h, P less than 0.01) but showed no diurnal variation post-partum. Plasma CRH was significantly elevated in late third trimester pregnancy (1.22 +/- 0.23 micrograms/l at 0900 h) but showed no diurnal change (1.30 +/- 0.28 micrograms/l at 1900 h). Moreover, no correlation between the free cortisol increase in late pregnancy and plasma CRH was noted despite a wide range of CRH levels (0.13-3.60 micrograms/l). In contrast, a significant correlation was observed between the serum progesterone increase and the salivary cortisol increase in late pregnancy (r = 0.70, P less than 0.05). These findings demonstrate that placental CRH is not the only regulator of maternal ACTH and cortisol release. Instead, our study suggests that placental CRH has little influence on baseline maternal adrenocortical function in pregnancy. The elevated salivary cortisol levels in pregnancy may be explained by glucocorticoid resistance owing to the antiglucocorticoid action of high progesterone concentrations.

A model for neuronal oscillations in the visual cortex. 1. mean-field theory and derivation of the phase equations

Abstract: We study a neural network consisting of model neurons whose efferent synapses are either excitatory or inhibitory. They are densely interconnected on a local scale, but only sparsely on a larger scale. The local clusters are described by the mean activities of excitatory and inhibitory neurons. The equations for these activities define a neuronal oscillator, which can be switched between an active and a passive state by an external input. Investigating the coupling of two of these oscillators we found their coupling behaviour to be activity-dependent. They are tightly coupled and almost synchronized if both oscillators are active, but weakly coupled if one or both oscillators are passive. This activity-dependent coupling is independent of the underlying connectivities, which are fixed. Finally, for coupled active oscillators we derive a simplified description by disregarding the amplitudes of the oscillators and working with their phases. We use this simplified description in a compagnion article to model the oscillations in the visual cortex.

The corticotrophin releasing hormone test in late pregnancy: lack of adrenocorticotrophin and cortisol response.

Abstract: Biologically active corticotrophin-releasing-hormone (CRH) is produced by the placenta in large amounts and can be measured in the maternal circulation during third trimester of pregnancy. Its physiological significance is unknown. To further investigate the action of CRH in pregnancy, we performed a standard CRH-test (1 micrograms/kg synthetic human CRH) in seven pregnant women 1 week prior to their calculated delivery data and 4-5 weeks post-partum. No response of plasma ACTH to CRH administration could be measured in any of the third trimester pregnant women. Post-partum, basal ACTH levels were significantly lower (1.6 +/- 0.3 vs 5.3 +/- 0.2 pmol/l) and reacted promptly to CRH administration (1.6 +/- 0.3-4.2 +/- 0.5 pmol/l; P less than 0.05). Concentration of cortisol in plasma and salivary cortisol paralleled the ACTH response to administration of CRH. However, one pregnant woman experienced physical and emotional stress during the CRH-test and reacted with a sharp rise in cortisol secretion. The lack of the ACTH and cortisol response in this study to exogenously administered CRH in third trimester pregnancy may be due to high circulating glucocorticoid concentrations, desensitization of the pituitary corticotroph and/or in part due to circulating specific CRH-carrier protein.

Long-term changes of salt-marsh communities by cattle grazing

Abstract: Over a period of 9 years a grazing experiment was carried out in the mainland salt marsh of the Leybucht (Niedersachsen) with three stocking rates, namely, 0.5 ha-1, 1 ha-1, and 2 cattle ha-1. These were also compared with an abandoned area. The results are based on sampling of the invertebrates in 1980, 1981, 1982, and 1988, and of the vegetation in 1980 and 1988. The rate of sedimentation is highest in the Puccinellia maritima-zone and decreases with the increase of stocking rates. The Elymus pycnanthus vegetation type becomes dominant in the higher salt marsh in the abandoned site. The canopy height decreases with increasing stocking rate, whereas a gradient in the structure of the vegetation develops with the lowest stocking rate. The population densities, the species-richness and the community diversity of invertebrates increases after the cessation of grazing. The high rate of sedimentation in the abandoned site promotes the immigration of species from higher salt marsh levels and adjacent grasslands, and eventually halotopophilous species and communities may disappear. On the other hand grazing reduces numerous species living both in or on upper parts of the vegetation or being sensitive to trampling by cattle. The community structure shows that the salt marsh ecosystem changed from a food web dominated by plant feeding animals to a food web dominated by animals foraging on detritus. The salt marsh management has to be differentiated into both ungrazed and lightly grazed areas (each 50%) or an overall grazing in large areas with less than 0.5 cattle ha-1.

Nonparametric measures of phenotypic stability. Part 1: theory.

Abstract: For an estimation of phenotypic stability of genotypes grown in different environments three stability parameters have been proposed which are based upon the ranks of the genotypes in each environment: In a two-way table with K rows (genotypes) and N columns (environments) the original data xij (=phenotypic value of the i th genotype in the j th environment (i=1,2,...,K;j=1,2,...,N)) are transformed into ranks for each of the N environments separately. We denote: rij=rank of genotype i in environment j. Then, a genotype i may be considered to be stable over environments if its ranks are similar over environments (maximum stability = equal ranks over environments). Each statistic for the similarity of the ranks in each row = genotype may be used as a stability parameter. Three different measures are proposed and discussed. One of these nonparametric measures is defined as a ratio between ‘variability of the rij's’ and ‘mean of the rij's’ and, therefore, it represents a confounding and simultaneous consideration of stability and yield. Differences among genotypes have an effect on the stability measures and may lead to differences in stability among genotypes when in fact there is no genotype-environment interaction. To avoid this ambiguity one may correct the xij values for the genotypic effects and the nonparametric measures may be computed using the ranks based on the corrected values xij *=xij−(\-xi.−\-x..)where \-xi.=marginal mean of genotype i and \-x\2=overall mean. Finally, approximate tests of significance based on the normal distribution are discussed for the two nonparametric measures ‘mean absolute rank difference’ and ‘variance of the ranks’ for 1) testing the stability of a certain genotype and 2) comparing the stabilities of different genotypes.

IL-1 alpha or tumor necrosis factor-alpha stimulate release of three NAP-1/IL-8-related neutrophil chemotactic proteins in human dermal fibroblasts.

Abstract: Human dermal fibroblasts in culture secrete three protein-like neutrophil chemotactic factors, when stimulated either with human rIL-1 alpha or IL-1 beta; not, however, after incubation with LPS These three fibroblast-derived neutrophil-activating proteins (FINAP) could be purified by subsequently performed reversed phase and size exclusion HPLC By high resolution SDS-PAGE, all the proteins were shown to migrate with an Mr of 6,700 (alpha-FINAP), 3,600 (beta-FINAP), and 5,300 (gamma-FINAP) All purified cytokine preparations were found to be chemotactic for human neutrophils In addition, all FINAP induced release of lysosomal enzymes in neutrophils Deactivation of chemotaxin-elicitable enzyme release showed cross-desensitization of all FINAP with NAP-1/IL-8 Western blot analysis of alpha-FINAP by using mAb against neutrophil-activating protein (NAP)-1/IL-8 reveals immunologic cross-reactivity with NAP-1/IL-8 By amino-terminal amino acid sequence analysis alpha-FINAP could be identified as the 77-residue extended form of NAP-1/IL-8 containing the 79-residue form as a minor contaminant Whereas beta-FINAP has been found to be a truncation product of alpha-FINAP, gamma-FINAP shows identity with authentic melanoma growth stimulatory activity with respect to retention time upon reversed phase HPLC, high resolution SDS-PAGE, and biologic properties, as well as amino-terminal amino acid sequence These data show that human dermal fibroblasts may actively participate in inflammatory reactions by secretion of proinflammatory cytokines

The South Atlantic Current

Abstract: In this paper we use the historical hydrographic data base for the South Atlantic Ocean to investigate (i) the hydrographic boundary between the subtropical gyre and the Antarctic Circumpolar Current (ACC), the Sub-tropical Front (STF), and (ii) the southern current band of the gyre, which is called the South Atlantic Current (SAC). The STF begins in the west in the Brazil-Falkland (Malvinas) confluence zone, but at locations at and west of 45°W this front is often coincident with the Brazil Current front. East of 45°W the STF appears to be a distinct feature to at least the region south of Africa, whereupon it continues into the Indian Ocean. The associated current band of increased zonal speed is the SAC, which, except for one instance, is found at or north of the surface STF until Indian Ocean water from the Agulhas retroflection is reached. A reversal of baroclinicity in the STF is observed south of a highly saline Agulhas ring, causing the SAC to separate from the STF and turn north into the Benguela Current. Zonal flow south of the STF is generally weak and serves to separate the South Atlantic and circumpolar currents. In the Argentine Basin, the SAC has a typical volume transport of 30 Sv (1 Sv = 106m3s−1) in the upper 1000 m relative to a deep potential density surface (σ4 = 45.87 kg m−3), and can be as high as 37 Sv. It is thus comparable to, or stronger than, the Brazil Current. In the Cape Basin, the transport of the SAC is reduced to about 15 SY before it turns north to feed the Benguela Current. In late 1983 this flow was joined by about 8 Sv of water from the Agulhas Current.

Distribution of parvalbumin immunoreactivity in the visual cortex of Old World monkeys and humans.

Abstract: The macaque visual system has been frequently used as a model for understanding functional aspects of human vision. There are, however, few studies directly comparing biochemically defined neuronal populations in the visual cortex of the two species. In this study we compared the distribution and morphological features of the parvalbumin-immunoreactive neuronal subpopulation within humans and Old World monkeys (Macaca fascicularis and Macaca mulatta) by using monoclonal antibodies against the Ca2(+)-binding protein parvalbumin (PV), a neuronal marker in the vertebrate cerebral cortex. Characteristic laminar density and distribution of PV is observed, matching that seen with cytochrome C-oxidase and gamma-aminobutyric acid (GABA) immunoreactivity. Thus, parvalbumin is prominent in the layers receiving afferents from the dorsal lateral geniculate nucleus. Terminal fields are rich in layer IVA and IVC and moderate in the blob-region of layer II-III of the monkey cortex. In the human visual cortex only layer IVC displays rich terminal fields. Parvalbumin is present in neurons within all layers of the cortex except layer I. Parvalbumin-immunoreactive (PV-ir) axons occur in different lamellae of the white matter containing axons belonging to association or projection neurons. The estimation of PV-ir neurons, determined for 50 microns-wide columns through the thickness of area 17, shows that the percentage of the total neuron number in area 17 of humans containing PV is 6.8 +/- 2.0%, and in the macaque monkey, 11.5 +/- 2.9%. The perikaryal area of PV-ir neurons varies according to the layer and is comparable in humans (109.3 +/- 40.8 microns2) and monkeys (94.3 +/- 29.5 microns2). However, the relative number of large PV-ir neurons is higher in humans. The immunoreactive product fills the thinnest cell processes and the shape of PV-ir neurons can be easily traced with the aid of a camera lucida. The shape of the neurons is similar in the two species studied, and they probably belong to non-spiny stellate, double-bouquet, chandelier, and basket cell classes. This study shows that parvalbumin acts as a marker for a subpopulation of interneurons in area 17, but it is also present in the geniculocortical as well as in corticocortical pathways. Moreover, the Old World monkey and human visual cortices have a similar, but not identical, distribution of this important calcium-binding protein.

Marine epibiosis. II. Reduced fouling on Polysyncraton lacazei (Didemnidae, Tunicata) and proposal of an antifouling potential index

Abstract: Polysyncraton lacazei is a colonial tunicate (family didemnidae) living in the NW-mediterranean rocky sublitoral. A thorough scanning of numerous colonies revealed that in spite of an apparently heavy local fouling pressure only one fouling species - a kamptozoan - is encountered with some regularity on Polysyncraton. We try to define the epibiotic situation of sessile marine organisms as composed of four epibiotic parameters: longevity or exposure time (A), epibiont load (E), colonizer pool (CP) and fouling-period (FP). Subsequently, these factors are combined to propose an "Antifouling Potential" index: AFP=(1-E/CP)×A/(FP+A). This index is intended to permit evaluating the relative antifouling defense potency to be expected in a given organism in a given epibiotic situation and to compare different cases of epibiosis and fouling.

Membrane vesicle formation due to acquired mitoxantrone resistance in human gastric carcinoma cell line EPG85-257.

Abstract: A newly established gastric carcinoma cell line (EPG85-257P) exhibited a high sensitivity to mitoxantrone (DHAD) as determined by a monolayer proliferation assay. The concentration to inhibit cell growth to 50% of controls (IC50) was 0.0022 µg/ml culture medium. The cells were continuously incubated for more than 4 months in the presence of stepwise increased concentrations of DHAD, and the IC50 was increased to 0.41 µg/ml, i.e. , 186.4-fold. This resistant variant was named EPG85-257RNOV. The EPG85-257RNOV cells became cross-resistant to Adriamycin with enhanced IC50 by 10.5-fold and to daunomycin with enhanced IC50 by 3.9-fold. No distinct resistance was observed to vinblastine, vincristine, and colchicine. Verapamil (10-6, 4 × 10-6 and 10-5 m) and cyclosporin A (10-6, 3 × 10-6 and 10-5 m) did not reverse DHAD resistance. As shown by immunocytochemistry (monclonal antibodies: C219 and JSB-1) and Northern blot analysis, DHAD resistance was not associated with the appearance of the multidrug resistance (MDR)-associated ( M r 170,000) P-glycoprotein or the overexpression of P-glycoprotein mRNA. The data indicate a chemoresistance pattern unlike typical MDR (often called “atypical” MDR). The phenotypes of parent and resistant EPG85-257 cells were compared using interference contrast microscopy, electron microscopy, and immunocytochemistry. After DHAD application the following structural characteristics were found to be associated with emergence of resistance: ( a ) intensive formation of surface vesicles in the resistant variant. Such vesicles were almost absent in sensitive cells; ( b ) the vesicles contained the selecting DHAD which was visualized by its blue color; and ( c ) in electron microscopy the vesicles were formed by an inner and an outer double membrane, presumably derived from the plasmalemma. These observations suggest a complex cellular mechanism responsible for DHAD resistance which includes formation of membrane vesicles, vesicular drug binding, and drug compartmentalization.

The Somali current at the equator: annual cycle of currents and transports in the upper 1000 m and connection to neighbouring latitudes

Abstract: Current measurements were obtained with moored stations during October 1984 to October 1986 in two consecutive deployments across the Somali Current on the equator. For the transport calculations the deficiency of conventional subsurface moorings, i.e. no data from close to the surface, had to be overcome using the historical ship drift climatology. While the current structure during the summer monsoon is that typical of a western boundary current, the profile in winter is far from being a weaker southward reverse of the summer situation. Below a thin surface layer of southward flow, there is a northward undercurrent between about 120 and 400 m depth. Below that, the flow reverses again to southward. This results in drastic differences in cross-equatorial monsoon season transports. While the summer mean transport is 21 Sv for the upper 500 m, the winter monsoon mean for that depth range is close to zero. The annual mean transport in the upper 500 m is 10 Sv northward. Very little transport is measured in the 500–1000 m depth range in either season or the annual mean. The almost closed mass budget of the boundary current system during the winter circulation allows a calculation of cross-equatorial heat transport, which comes out to −3 × 1014 W (southward) for the northeast monsoon season mean. The heat flux associated with the annually varying part of the boundary current is small, only about −0.3 × 1014 W or about 5% of the total cross-equatorial heat flux as estimated by other methods. By combining the equatorial measurements with earlier off-equatorial current observations, particularly at 2°−4°S and 5°N, and with property distributions (salinity and oxygen) on isopycnal surfaces, analysed from the historical data file, a synopsis of the seasonal circulation changes of the entire Somali Current system between about 4°S and 12°N is then derived.

Partial 16S rRNA primary structure of five Actinomyces species: phylogenetic implications and development of an Actinomyces israelii-specific oligonucleotide probe.

Abstract: The intra- and intergeneric relationships of the genus Actinomyces were determined by comparing long 16S rRNA sequences, generated by reverse transcriptase. All species formed a phylogenetically coherent cluster in which Actinomyces bovis, A. viscosus, A. naeslundii, A. odontolyticus and A. israelii constituted genetically well defined species. A. israelii DSM 43322 (serotype 2) was not closely related to three other strains of this species (serotype 1) and, as judged from phylogenetic distances, could be accommodated within A. naeslundii, or represent a new species. In contrast to previous findings, members of the genus Actinomyces appear to be related to Bifidobacterium bifidum. Sequence information was used to develop an oligonucleotide probe for the A. israelii serotype 1 strains, which did not react with the serotype 2 strain or with rRNA from strains of eight Actinomyces species.

Lipopolysaccharide-stimulated human monocytes secrete, apart from neutrophil-activating peptide 1/interleukin 8, a second neutrophil-activating protein. NH2-terminal amino acid sequence identity with melanoma growth stimulatory activity.

Abstract: Purification of monocyte-derived NAP-1/IL-8 by preparative reversed-phase (RP)-HPLC led to the detection of a second peak with polymorphonuclear leukocyte (PMNL)-activating (degranulation, chemotaxis) properties. The monokine responsible for this biological activity, which we tentatively termed NAP-3, could be purified to homogeneity by three different RP-HPLC steps. Tricine-SDS-PAGE analysis gave a single line at Mr 5.3 kD (NAP-1/IL-8 = 5.8 kD). NH2-terminal amino acid sequence analysis read as a major sequence (ASVATELRXCXLQT. .), which shows greater than 40% homology to that of NAP-1/IL-8. The sequence is identical to that found for the 13-kD moiety of melanoma growth stimulating activity (MGSA) and the product of the oncogene gro. Determination of neutrophil chemotactic activity of NAP-3 revealed a typical bell-shaped dose-response curve (ED50 = 2 ng/ml) with no significant neutrophil chemotactic activity at doses greater than 200 ng/ml. Also, in cytochalasin B-pretreated PMNL, NAP-3 elicited release of myeloperoxidase and beta-glucuronidase. Crossdesensitization studies in PMNL enzyme release revealed crossreactivities with the NAP-1/IL-8-R on PMNL. NAP-3 (MGSA/gro) appears to represent the first member of the novel supergene family of beta-thromboglobulin-like host defense cytokines, which expresses both mitogenic as well as proinflammatory properties at the nanogram level.

Analysis of calcific deposits in calcifying tendinitis.

Abstract: The precise composition of calcific deposits in calcifying tendinitis is still unknown. However, analysis of such deposits can help to elucidate the disease's pathogenesis. Twenty-five calcific deposits from various phases of the disease were analyzed by several methods. The macroscopic appearance of the specimens during the acute phase of calcifying tendinitis resembled a milky emulsion; in contrast, it resembled a granular conglomerate during the chronic phase. X-ray diffraction showed a poorly crystallized hydroxyapatite lattice (resembling that in bone) in both phases. Infrared spectroscopy revealed variable H2O, CO3, and PO4 contents in all samples, but no significant differences in these proportions were seen in the two phases of the disease. Organic molecules were seen in addition in all samples. Scanning electron microscopy showed similar morphologies of the crystalline conglomerates of both phases, with somewhat round, nongeometric structures. The macroscopic difference was not reflected in the mineralogic structure. Neither a chemical compositional change nor a change in the crystal lattice was observed. The disintegration of the conglomerates probably depends on a change in the bonding capacity of the organic molecules, which in turn initiates phagocytosis in the resorptive phase.

Hyperthermophilic archaebacteria within the crater and open-sea plume of erupting Macdonald Seamount

Abstract: HYPERTHERMOPHILIC archaebacteria, found in terrestrial and submarine hydrothermal areas1–6, thrive at temperatures between 80 and 110 °C and are unable to grow below 60 °C. They represent life at the known upper temperature limit. On the continent, their biotopes are solfataric fields and hot springs. Within the marine environment, hyperthermophilic archaebacteria have been found in shallow-water hydrothermal fields as well as in deep hot sediments and vents1,2,4–6. They include strictly anaerobic sul-phidogenic and methanogenic chemolithoautotrophs as well as fermentative and sulphidogenic heterotrophs, and are important as primary producers and consumers of organic matter within high-temperature ecosystems. Their distribution and possible modes of dissemination are at present unknown. Here, we report for the first time on a community of hyperthermophilic archaebacteria within the active zone of an erupting submarine volcano7, and on its spread through the ensuing cooled-down open-ocean plume. Most of the organisms are close relatives of species previously known only from a submarine solfataric field in Italy, whereas others are new. By their conversion of volcanic gases and sulphur at high temperatures, archaebacterial communities living in seamounts may be important participants in marine ecological, geochemical and volcanic processes.

A model for neuronal oscillations in the visual cortex. 2. phase description of the feature dependent synchronization

Abstract: In a previous paper we have shown, that it is possible to model the oscillations observed in an orientation specific column in the visual cortex by coupling excitatory and inhibitory subpopulations of neurons which compose the column, and that these oscillations can be described by the phases of the corresponding limit cycle oscillators. By coupling different columns via long but finite range sparse interactions, we generate in the phase description stimulus dependent multiplicative couplings which explain experimentally observed synchronization effects.