Effects of losartan on the collagen degradative enzymes in hypertrophic and congestive types of cardiomyopathic hamsters

The present study was undertaken to determine the effects of AT1 receptor blockade which occurred in response to losartan, on the extracellular matrix (ECM) degradation process in the Bio 14.6 (n = 12) and Bio 53.58 (n = 12) strains which are referred as models of hypertrophic and dilated cardiomyopathy, respectively. The administration of losartan (30 mg/kg/day) in hamsters from 10–20 weeks of age reduced the accumulation of the left ventricular collagen matrix in both of the Bio 14.6 and the Bio 53.58 strains. According to the RTPCR, the levels of mRNA for matrix metalloproteinase (MMP) and the tissue inhibitor of MMP (TIMP) were examined. MMP1, 2, 3, and 9 were more enhanced in both myopathic strains than in the control F1 strains. With losartan, the levels of MMP1, 2, 9, TIMP1 and 2 decreased in the both strains but those for MMP3 did not in Bio 14.6 strains. TIMP3 and 4 mRNA levels did not change in any of the experimental hamsters, whether treated or untreated with losartan. The Western blots also showed similar observations in the both strains as seen in mRNA expressions although MMP2 in the Bio 53.58 strains did not differ between treated and untreated with losartan. Although losartan has an inhibitory effect on collagen accumulation in the development of cardiomyopathy, MMPs (1, 2, 9) and TIMPs (1, 2) seem to be susceptible to responding to losartan in Bio cardiomyopathic hamsters.     

Mitochondrial genetic damage induced in yeast by a photoactivated furocoumarin in combination with ethidium bromide or ultraviolet light

Summary Ethidium bromide (EB) and ultraviolet light (UV) in combination are known to produce a synergistic induction of petite mutants in yeast. Two other agents were combined with EB, 3-Carbethoxypsoralene (3 CPs) activated by 365 nm light or rays. EB in combination with 3 CPs also resulted in an enhanced production of petite mutants. After the photoaddition of 3 CPs in exponential phase cells, recovery of the petite mutation during dark liquid holding was inhibited by the presence of EB producing an enhanced number of petite mutants. The behavior of mitochondrial antibiotic resistance markers after individual and combined treatments with EB and 3 CPs indicates a random loss of markers after EB and a preferential loss of a certain region for the 3 CPs photoaddition. The combination of the two agents leads to an additivity of total drug marker losses rather than a synergistic loss. The combination of EB with rays produced no enhancement in petite induction. A combination of UV and 3 CPs showed a synergistic interaction for petite induction. These results indicate that the three agents, EB, UV and 3 CPs photoaddition may share a common repair step for mitochondrial lesions.     

Ultrastructure of four types of striated muscle fibers in the atlantic hagfish (Myxine glutinosa,L.)

Summary Four types of striated muscle fibers with distinctive ultrastructure were defined in the Atlantic hagfish (Myxine glutinosa, L.): white, intermediate, and red fibers of m. parietalis, and red fibers of m. craniovelaris.White fibers are thick, contain very few mitochondria and fat vacuoles, and possess distinct and separate myofibrils with thin Z-disks and distinct M-lines. Intermediate fibers are thinner, possess largely similar myofibrils that often are even better separated due to a higher content of fat vacuoles and especially mitochondria and glycogen granules. Red fibers of m. parietalis contain large amounts of mitochondria, fat vacuoles, and glycogen granules. Their myofibrils possess M-lines, and although branching more, the myofibrils of red fibers conform with a Fibrillenstruktur pattern like those of white and intermediate fibers. Red fibers of m. craniovelaris are very thin, possess many smaller fat vacuoles, and large amounts of mitochondria and glycogen granules. The myofibrils are significantly thinner than in m. parietalis fibers, run as quite independent well separated units, possess thicker Z-disks, and lack M-lines. Large amounts of myosatellite cells are associated with these red fibers.Triads are located near A/I-junctions in all four fiber types and occur irregularly, the density of triads being different in the various fiber types.We are indebted to Dr. Finn Walvig, Biological Station, University of Oslo, Drøbak, for supply of hagfishes, and we also wish to thank Dr. Jan K. S. Jansen, Institute of Physiology, University of Oslo, for valuable suggestions during this study.     

Harzkonservierte fossile Vogelfedern aus der untersten Kreide

Zusammenfassung Harzkonservierte Fossilien ermöglichen bei Anwendung adäquater Methoden die morphologische Analyse der Feinmerkmale bis zur Auflösungsgrenze des Lichtmikroskops, Beobachtung in verschiedenen Ebenen und Richtungen, und somit konkrete Rückschlüsse auf die Wirkung und Bedeutung der Einzelelemente und des Gesamtgefüges.Eine so eingehende funktionsmorphologische Analyse mit Berücksichtigung der Positionsvariation (graduell verschiedene Gestaltung in gesetzmäßiger Abhängigkeit von der Lage innerhalb der Gesamtfeder) der Einzelelemente wie Abzweigungs-, Knick-, Neigungswinkel, Krümmung, Länge, Dicke, Querschnitt, Dichte, Differenzierungsgrad der verschiedenen Abschnitte von Rhachis, Rami, Radii inklusive Häkchen und Cirren wird erstmals für fossile Vogelfedern geliefert (hier als Abriß zu einer dokumentarisch und thematisch ausführlicheren Darstellung in Stuttgarter Beiträge zur Naturkunde).Diese Federn entstammen der untersten Unterkreide und sind damit nur relativ wenig jünger alsArchaeopteryx. Sie weisen extrem differenzierten Aufbau auf, der auf hohe flugtechnische und wärmeisolierende Leistungsfähigkeit schließen läßt.Die hier vorgelegten funktionsmorphologischen Ermittlungen an fossilen Körperkonturfedern mögen auch zu einer intensiveren Analyse der bis jetzt stark vernachlässigten Untersuchung ganz normaler Körperfedern rezenter Vögel anregen. Erst dann, nach umfassender Kenntnis ihrer Ausgestaltung innerhalb der verschiedensten rezenten Vogelgruppen, läßt sich überzeugend begründen, ob und wieweit die hier vorgelegten Federn dieses Unterkreide-Vogels noch ursprüngliche Elemente (Plesiomorphien) oder ihnen eigene Sonderbildungen (Autapomorphien) aufweisen; das gilt sowohl für morphologische wie für funktionelle Elemente der Gesamtstruktur.

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Resin-preserved fossil bird's feathers from the Lowermost Cretaceous

Summary Parts of some feathers, originating from a single bird, were discovered in our collections of Lower Cretaceous amber from the Lebanon mountains — which, in general, contains the oldest terrestrial microfossils preserved with all morphological details.These contour feathers of the trunk, which are nearly as old as Archaeopteryx (Lowermost Cretaceous: Neocomian/Uppermost Jurassic: Kimmeridigian) were studied with magnifications of 500–900 in several levels by a special technique. (In normal fossils, i.e., impressions, the granulation of the sediment and the fossil's bulky carbon remainders cause a blurred image even at a magnification of merely 100).Special emphasis was laid on the study of the individual elements' gradual variation, depending on the respective position within the total feather (position variation). Where appropriate, an analysis of lengths, quantity, degree of differentiation, angle of inclination, break, and branching, cross-sectional view, curvature, etc. of the rhachis, rami, distal and proximal radii, barbicles, hooklets, etc. were undertaken. [Through measurements of the depth of details the effects caused by a sloping position (apparent variation) may be precisely separated from the real variation.]On the basis of such a detailed knowledge of structure and relative position a thorough functional analysis of the single elements as well as the total system is given.Principal features: The production of plain stability in the feather's center, and of flexibility in its apical and lateral rims; dispersion of forces in case of pressure or a pulling load; function of the hooklets (which donot serve as an interlocking mechanism while the feather is in the normal resting position, but function with increasing braking action only when a neighboring ramus diverges to a precisely defined extent from its resting position) including the mechanism of their unhooking; devices for the avoidance of harmful hooking into contacted parts of other feathers; production of maximal stability by minimal air resistance, and of minute chambers (<0,00001 mm³) with still air for optimal heat isolation.Apart from this abstract, further information, accompanied by numerous figures, will be given in a later paper in Stuttgarter Beiträge zur Naturkunde.

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Veränderte Fassung eines am 11. 10. 1971 gehaltenen Vortrages auf der 83. Jahresversammlung der Deutschen Ornithologengesellschaft in Bonn.     

Activation of peritoneal macrophages in patients with gynecological malignancies by sizofiran and recombinant interferon-γ

We investigated the influence of the combined use of sizofiran, a-1,3-glucan and a recombinant interferon- (rIFN-) upon biological activities of peritoneal macrophages (M). The number of peritoneal M and the production of cytokines (interleukin-1, interferon- and tumor necrosis factor) was increased by the combined treatment. Fully activated peritoneal M based on the increased number of elongated pseudopods were observed by electromicroscope. Sizofiran seems to assure a sufficient supply of M to kill tumor cells in the peritoneal cavity and co-administered rIFN- seems to directly stimulate the accumulated M in addition to its direct cytotoxicity against tumor cells. This combination therapy may be a step to the prevention of the recurrence of gynecological malignancies including ovarian cancer, after a negative second-look laparotomy.Abbreviations rIFN- recombinant interferon- - IL-1 interleukin-1 - TNF tumor necrosis factor - SLL second look laparotomy     

Silver staining the chromosome scaffold

Cytological silver-staining procedures reveal the presence of a core running along the chromatid axes of isolated HeLa mitotic chromosomes. In this communication we examine the relationship between this core and the nonhistone chromosome scaffolding, isolated and characterized in previous publications from this laboratory. When chromosomes on coverslips were subjected to the steps used for scaffold isolation in vitro and subsequently stained with silver, the characteristic core staining was unaffected. Control experiments suggested that the core does not contain large amounts of DNA. When scaffolds were isolated in vitro, centrifuged onto electron microscope grids, and stained with silver, they were found to stain selectively under conditions where specific core staining was observed in intact chromosomes. These results suggest that the nonhistone scaffolding is the principal target of the silver stain in chromosomes.     

Ultrastructural localisation of TGF-beta exposure in dentine by chemical treatment

Transforming growth factor- (TGF-) sequestered in dentine matrix has an important role in dental tissue repair after injury and its exposure at sites of injury may stimulate tertiary dentinogenesis. This study aimed to investigate the expression of TGF- isoforms in mature human dentine matrix and the ability of chemical treatments to expose TGF- on the cut surface of dentine using gold immunolabelling and subsequent scanning electron microscopy examination. TGF-1 was the only isoform that could be detected in human dentine and the nature of the chemical treatment of the tissue influenced its detection. EDTA treatment provided good exposure of TGF-1 on the dentine surface, whilst citric acid and sodium hypochlorite treatments revealed lesser amounts of this isoform. Only minimal staining for TGF-1 was observed in samples treated with phosphate-buffered saline. TGF-2 and -3 could not be detected in the specimens with any of the treatments. This study suggests that TGF-1 is the only TGF- isoform expressed by human odontoblasts to be sequestered in dentine implying that differences in isoform–extracellular matrix interactions may exist. Information on chemical treatment of tissue specimens for immunostaining may provide a useful basis for selection of tissue preparation techniques for clinical restorative treatment procedures to facilitate TGF- mediated reparative processes at sites of dental injury.     

Transmembrane electron transport and the neutral theory of evolution

Based on the concept of pairs of basic functional states the evolution of the first chemiosmotic mechanism of energy conversion is discussed in terms of point mutations, gene duplications and of the neutral theory of evolution. A model for estimating the overall probability of the evolutionary step in question is presented, both for the selectionist and neutralist position. It is concluded that, concerning the present stage of knowledge, the evolution of transmembrane electron transport is an unsolved problem in evolutionary biology.     

On the role of the invariant glutamine at position 54 in the human choriogonadotropin β subunit

The twelve Cys and eight of the non-Cys residues are invariant in the glycoprotein hormone subunits from a variety of mammalian species. -Gin-54 of human lutropin (hLH) and choriogonadotropin (hCG) is one of these invariant amino acid residues. A single AG mutation in the LH gene of a patient presenting with hypogonadism resulted in the replacement of Gin-54 with Arg [1]. The authors also reported that an expressed mutant of hLH, with Arg replacing Gin-54, associated with the subunit, but there was no demonstrable binding of the mutant hormone to receptor. We have replaced Gin-54 in hCG with Glu and with Lys using site-directed mutagenesis. The expression plasmids pRSV-hCG (wild-type and mutants) were transiently transfected into CHO cells containing a stably integrated gene for bovine , and the media were analyzed for holoproteins, which were characterizedin vitro using competitive binding and steroidogenic assays with MA-10 cells. hCG(Glu-54) bound to almost as well as hCG wild-type, and the resulting heterodimer competed with [¹²⁵l]hCG binding to the LH/CG receptor and stimulated progesterone production to the same extent as the wild-type control. However, the apparent potencies, as judged by ED₅₀s, were less than those of the wild-type control, the effect being more pronounced in binding than in steroidogenesis. In contrast, hCG(Lys-54) associated very poorly with . Our results suggest that while Gin-54 in hCG participates in receptor binding, its major function appears to involve binding. Such dual functionality leads to interesting models for holoprotein formation and receptor binding.     

„Kolbenbildungen“ der Muskelfasern des menschlichen Kehlkopfs

Zusammenfassung Fasern der menschlichen Kehlkopfmuskulatur weisen seitliche Aussackungen auf, die unter dem Sarkolemm in lockerer Anordnung Kerne, Lysosomen, Lipofuscingranula und Mitochondrien mit oft konzentrisch angeordneten Cristae enthalten. Sie sind mit den lichtmikroskopisch bekannten End- bzw. Seitenkolben identisch. Diese Aussackungen werden von den gefäßnahen subsarkolemmalen Mitochondrienanhäufungen eines bestimmten, auch in der übrigen Skelettmuskulatur weitverbreiteten Muskelfasertyps abgeleitet. Es wurden keine Verbindungen mit Nervenfasern gefunden. Im Gegensatz zu Goerttler können wir diese Bildungen deshalb nicht als Mechanorezeptoren deuten. Die Endkolben werden als sekantial getroffene Seitenkolben aufgefaßt. Da die Aussackungen der Fasern auch bei gesunden jungen Männern in der Kehlkopfmuskulatur regelmäßig auftreten, handelt es sich hier nicht um eine krankhafte Bildung, wenn auch die Faser im Bereich der Aussackungen einen degenerativen Prozeß durchzumachen scheint.

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Summary Fibers of human larynx muscles show lateral dilatations of the sarcolemma containing loosely disposed mitochondria, lysosomes and eventually one or more nuclei. The cristae of the mitochondria often are arranged concentrically. Corresponding fiber dilatations have already been described by light microscopists as side- resp. end-bulbs.Our electron-microscopical observations lead to the conclusion that the dilatations are derived from accumulations of mitochondria beneath the sarcolemma which in similar form — but smaller — are characteristic of one type of the different muscle fibers, frequently to be found in other muscles of the body. Both subsarcolemma accumulations of mitochondria are close to the muscle capillaries.The fiber dilatations have no connections with nerve axons, and therefore cannot be interpreted as mechanoreceptors (Goerttler, 1960). The end-bulbs are supposed to be secantially (or obliquely) cut side-bulbs. We do not consider them pathologic since they are regularly found in fibers of healthy young men. On the other hand, they may represent a circumscribed degenerative alteration the origin of which remains to be explored.

     

Plant regeneration via somatic embryogenesis in Styrian pumpkin: cytological and biochemical investigations

Somatic embryo formation was induced from cotyledon explants of Styrian pumpkin (Cucurbita pepo L. subsp. pepo var. styriaca Greb.) by using a solid MS medium supplemented with 16.11M NAA and 4.44M BA or 26.85M NAA and 13.32M BA. The callus proliferation was more efficient on medium supplemented with 26.85M NAA and 13.32M BA. In contrast, the embryogenic response was higher on medium with lower concentrations of growth regulators (16.11M NAA and 4.44M BA). The time needed for embryo induction did not depend on medium composition. Embryos in globular stage were transferred to three different maturation media, containing 2.89M GA₃ in combination with 0.54M NAA, 11.42M IAA and growth regulator-free medium. The germination rate was the highest when embryos were cultured on medium with 11.42M IAA. Plantlets grown on this medium achieved maturity suitable for transplantation into soil within 9 to 10weeks. The regenerated plants were successfully transferred into field and developed fertile flowers and set fruits. Biochemical analysis showed significant lower total glutathione levels among in vitro grown plantlets compared to seedlings grown in soil. When the plantlets were transferred into soil, they reached a normal size within a month and the glutathione concentration was comparable to seed-derived plants at the same developmental stage. Transmission electron microscopy was used to investigate possible differences in the ultrastructure of cells from callus cultures, and leaf cells of regenerated and seed-derived plants. Differences in the ultrastructure were found within chloroplasts which contained only single thylakoids, large starch grains and small plastoglobuli in callus cells in comparison to leaf cells, which possessed a well developed thylakoid system, small starch grains and large plastoglobuli.     

Evolutionary origin of the class A and class C β-lactamases

Summary The protein sequences of 18 class A -lactamases and 2 class C -lactamases were analyzed to produce a rooted phylogenetic tree using the DD peptidase of Streptomyces R61 as an outgroup. This tree supports the penicillin-binding proteins as the most likely candidate for the ancestoral origin of the class A and class C -lactamases, these proteins diverging from a common evolutionary origin close to the DD peptidase. The actinomycetes are clearly shown as the origin of the class A -lactamases found in other non-actinomycete species. The tree also divides the -lactamases from the Streptomyces into two subgroups. One subgroup is closer to the DD peptidase root. The other Streptomyces subgroup shares a common branch point with the rest of the class A -lactamases, showing this subgroup as the origin of the non-actinomycete class A -lactamases. The non-actinomycete class A -lactamase phylogenetic tree suggests a spread of these -lactamases by horizontal transfer from the Streptomyces into the non-actinomycete gram-positive bacteria and thence into the gram-negative bacteria. The phylogenetic tree of the Streptomyces class A -lactamases supports the possibility that horizontal transfer of class A -lactamases occurred within the Streptomyces.     

The contribution of size-fractionated plankton to biomass and primary production of phytoplankton in saline–alkaline ponds

Primary productivity, biomass and chlorophyll-a of size fractionated phytoplankton (<0.22 m, <3 m, <8 m, <10 m, <40 m, <64 m, <112 m and <200 m) were estimated in 6 ponds and 5 experimental enclosures. The results showed that the planktonic algae less than 10 m are important in the biomass and production of phytoplankton in saline–alkaline ponds. The production of size fractionated phytoplankton corresponding to <112 m, <10 m and <3 m in saline–alkaline ponds were 10.5 ± 6.6 , 8.6 ± 5.4 and 0.33 ± 0.1 mgC l^–1 d^–1, respectively. Mean community respiration rate was 1.80 ± 0.73, 1.69 ± 0.90 and 1.38 ± 1.12 mgC l^–1 d^–1, respectively. The average production of phytoplankton corresponding to micro- (10–112 m), nano- (3–10 m) and pico- (<3 m) were 1.61, 8.30 and 0.33 mgC l^–1 d^–1, respectively. The ratio of those to the total phytoplankton production was 15%, 79% and 3%, respectively. The mean respiration rate of the different size groups was 0.11, 0.31 and 1.38 mgC l^–1 d^–1; the ratio of those to total respiration of phytoplankton was 6%, 17% and 77%, respectively. The production of size-fractionated phytoplankton corresponding to <200 m, <10 m and <3 m in enclosures was 2.19 ± 1.63, 2.08 ± 1.75 and 0.22 ± 0.08 mgC l^–1 d^-1, respectively. Mean community respiration rates were 1.25 ± 1.55, 1.17 ± 1.42 and 0.47 ± 0.32 mgC l^–1 d^–1, respectively. The average production of phytoplankton corresponding to micro- (10–200 m), nano- (3–10 m) and pico- (<3 m) plankton was 0.11, 1.86 and 0.22 mgC l^–1 d^–1, respectively. The ratio of those to the total production of phytoplankton was 5%, 85% and 10%, respectively. The mean respiration rate of different size groups were 0.08, 0.72 and 0.46 mgC l^–1 d^–1, the ratio of those to total respiration of phytoplankton was 6%, 57% and 37%, respectively. The concentrations of chlorophyll-a of the phytoplankton in the corresponding size of micro- (10–112 m), nano- (3–10 m) and pico- (<3 m) plankton in the experimental ponds were 19.3, 98.2 and 11. 9 g l^–1, respectively. The ratio of those to the total chlorophyll-a was 15%, 76% and 9%, respectively. The concentrations of chlorophyll-a of phytoplankton micro- (10–200 m), nano- (3–10 m) and pico- (<3 m) plankton in enclosures were 1.7, 34.3 and 3.0 g l^–1, respectively. The ratio of those to the total chlorophyll-a was 4%, 88% and 8%, respectively.     

Somatic embryogenesis and plant regeneration in wild cotton (Gossypium klotzschianum)

A simple and efficient method for high frequency somatic embryogenesis and plant regeneration from hypocotyl-derived cultures and suspension cultures of Gossypium klotzschianum Anderss, a wild, diploid species of cotton is described here. Embryogenic cultures were induced from hypocotyl sections on MSB medium with 0.9 M 2,4-D and 2.32 M kinetin. MSB medium containing 0.045 M 2,4-D, 0.93 M kinetin, 2.46 M IBA promoted embryogenic culture proliferation and embryo development. Suspension cultures with 0.23 M 2,4-D and 0.93 M kinetin also produced many embryos. Somatic embryos cultured on MSB medium with PGRs produced secondary embryos, and embryos developed into normal plantlets on PGR-free MSB medium. Regenerated plantlets were transferred onto the quarter-strength MSB medium with 0.5% active charcoal to avoid recallusing. Hypocotyls were better than cotyledons for culture induction and plant regeneration. 2,4-D and kinetin were essential for culture induction and maintenance.     

Transforming growth factor-beta isoform expression in mature human healthy and carious molar teeth

Transforming growth factor (TGF)- isoforms have been implicated in cellular signalling during tooth development and repair, but little is known of their cellular localisation or distribution within the dental tissues in the mature tooth. This study investigated the presence of TGF-1, 2 and 3 isoforms in tissues of sound and carious human molar teeth, to understand better the expression of TGF-s during health and disease. In healthy tissues, odontoblasts, cells of the cell rich layer, pulpal fibroblasts and endothelial cells were stained to varying degrees for all isoforms, with TGF-3 showing the greatest intensity and TGF-1 the weakest intensity. Similar patterns of staining were observed in carious teeth; however, TGF-1 showed significantly increased staining intensity within odontoblasts and pulpal cells of carious teeth (p<0.001). Biochemical analysis showed greater amounts of TGF-1 in tertiary dentine than in primary dentine samples. The expression of TGF-s in odontoblasts and the increased presence of TGF-1 in tertiary dentine suggest that these isoforms may be important in odontoblast behaviour and the modulation of the tissue response to injury.     

The reactions of three species of grasshopper to simple visual stimuli at different temperature-humidity conditions

The effect of the temperature-humidity factor on the reaction of two different visual stimuli has been investigated with Chorthippus brunneus (Thunb.) (= Chorthippus bicolor Charp.), Chorthippus longicornis (Latr.) (= Ch. parallelus Zett.) and Mecostethus grossus (L.). At low and high temperatures (high and low relative humidities), the three species show a greater preference for surroundings with vertical stripes than for white surroundings. At medium temperature and relative humidity, the preference for white surroundings is greater than for surroundings with vertical stripes. In a comparison between the three species at high temperature, they show regarding their intensity of preference for surroundings with vertical stripes a ranking order which is identical with that of their preference for dense grass vegetation in natural environments. In a comparison between and at high temperature, show a greater preference for surroundings with vertical stripes than .

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zusammenfassung Die Wirkung des Temperatur-Luftfeuchtigkeits-Faktors auf die Reaktion gegenüber zwei optischen Reizen wurde bei Chorthippus brunneus (Thunb.) (= Chorthippus bicolor Charp.). Chorthippus longicornis (Latr.) (= Ch. parallelus Zett.) und Mecostethus grossus (L.) untersucht. Bei niederen und hohen Temperaturen (hoher und niederer relativer Luftfeuchtigkeit) zeigen die drei Arten eine größere Bevorzugung für Umgebungen mit vertikalen Streifen als für weiße Umgebungen. Bei mittlerer Temperatur und relativer Feuchtigkeit ist die Bevorzugung weißer Umgebung größer als für Umgebungen mit vertikalen Streifen. Bei einem Vergleich der drei Arten bei hoher Temperatur ergibt sich hinsichtlich der Stärke ihrer Bevorzugung für vertikal gestreifte Umgebung eine Rangfolge, die mit der ihrer Bevorzugung dichter Grasvegetation in natürlicher Umgebung identisch ist. Bei einem Vergleich zwischen und bei hoher Temperatur zeigen die eine größere Präferenz für Umgebung mit Vertikalstreifung als die .

     

Genetics of Ia-like alloantigens in chickens and linkage withB major histocompatibility complex

Two sets of backcross matings were performed to test for linkage between genes coding for the Ia-like antigens (Ia) and the B erythrocyte antigens (Ea-B) of the chicken. Evidence is presented which indicates that the la antigens are determined by a single codominant locus and that theEa-B and Ia loci are on the same chromosome. Failure to detect a single recombinant between theEa-B and Ia loci out of 208 progeny suggests close linkage of the two genes with a map distance of up to about 2 centimorgans. The Ia genes are thus included in theB major histocompatibility complex of the chicken.     

Idioms of distress: Kinship and sickness among the people of the Kingdom of Tonga

Idioms of distress refers to the popular expression of emotional tension that arises in the relationship between sickness and kinship. By reference to case studies and discussions among the Polynesian people of Tonga, the author shows where such tension arises and how it influences the sickness process. Sickness is necessarily a collective phenomenon which can best be understood not simply as a clinical event, but as an experience that is part of the experience of family. Various ways of expressing distress as a reflexive encounter between personal and cultural meaning systems are reviewed, as are several new concepts such as doing sickness as kinship, and turning in the process of decision making in the kinship management of sickness. The explanatory models of sickness in Tonga are shown to encompass culturally sanctioned expressions of distress as part of the adaptive coping mechanisms in that society. Distress frequently emerges in somatic form, as a number of studies have shown. However, the author emphasizes the kinship meaning of sickness, kinship management and sickness therapy, the adaptive process of idiomatic expressions of distress, which are expanded here and offered as potential avenues for elaboration in other cultural milieu. Two aspects of the notion idioms of distress are noted, and the phenomenon is understood as a process which acts as a prime mover in social change.     

Uptake and metabolism of benzyladenine during shoot organogenesis in Petunia leaf explants

Benzyladenine (BAP) uptake and metabolism were characterized during the key stages of shoot organogenesis in leaf explants of Petunia MD1. Using leaf explant transfer experiments, it was shown that exposure to 2.2 M BAP for 6, 8 or 10 days induced shoot formation on 27, 80 and 100% of the explants respectively, with a concomitant increase in the number of shoots per explant. BAP uptake and metabolism were characterized in leaf explants after 1, 3, 6 or 10 days exposure to [³H]BAP or 10 days exposure plus an additional 2 days on basal medium (10+2). BAP and 9--D-ribofuranosyl-BAP ([9R]BAP) were detected at days 1 and 3 only. Therefore, the BAP free base was not detectable during the shoot induction period between days 6 and 10, as defined by leaf transfer experiments. The BAP ribotide pool was largest on day 1 and decreased to day 10+2. It is possible that the BAP ribotide pool provided either the active cytokinin itself or acted as a short-term storage form for the active cytokinin in petunia shoot organogenesis. Other metabolites detected in petunia leaf tissue included 7--D-glucopyranosyl-BAP ([7G]BAP), 9--D-glucopyranosyl-BAP ([9G]BAP) and an unidentified metabolite C.Abbreviations BAP benzyladenine - [7G]BAP 7--D-glucopyranosyl-BAP - [9G]BAP 9--D-glucopyranosyl-BAP - [9R]BAP 9--D-ribofuranosyl-BAP - [9R-5P]BAP 5-monophosphate of [9R]BAP - [9R-5PP]BAP 5-diphosphate of [9R]BAP - [9R-5PPP]BAP 5-triphosphate of [9R]BAP - TEA Triethylamine This research was supported in part by NSF Grant DCB-8917378 to J.D.C. and USDA-CRGO Grant 89-37261-4791 to T.J.C.