A cyclin protein modulates mitosis in the budding yeast Saccharomyces cerevisiae

Summary For the budding yeast Saccharomyces cerevisiae the mitotic cell cycle is coordinated with cell mass at the regulatory step start. The threshold amount of cell mass (reflected as a critical size) necessary for start is proportional to nutrient quality. This relationship leads to a transient accumulation of cells at start, termed nutrient modulation, upon enrichment of nutrient conditions. Nutrient enrichment abruptly increases the critical size needed for start, causing the smaller cells, produced in the previous cell cycle, to be delayed at start while growing larger. Here we show that, in S. cerevisiae, a second cell-cycle step, at mitosis, also exhibits nutrient modulation, and is, therefore, another point of cell-cycle regulation. At both mitosis and start, nutrient modulation was found through mutation to be regulated by the activity of the cyclin-related WHI1 (CLN3) gene product.     

Intratypic antigenic heterogeneity of Coxsackie B viruses

Summary Neutralization tests, employing the cytopathogenic effect in tissue culture tubes, with a variety of homotypic antisera and strains of Coxsackie B viruses often yielded high titers in early readings and low titers in late readings — the break-through phenomenon — and occasionally also low, early-reading titers with heterologous, homotypic sera, which gave high titers with the homologous strains. Of 27 strains of Goxsackie B 1 to B 5, that were tested, 10 showed no break-through tendency while others showed varying degrees of break-through, without reference to any evidence of intratypic antigenic variation. There was a positive correlation between a small number of tissue culture passages away from man or mouse brain and the break-through tendency. Moreover, strains without break-through tendency yielded viral populations with marked break-through properties after a single intracerebral passage in newborn mice, and even after two subsequent tissue culture passages. Plaque-purified progeny exhibited the break-through phenomenon to the same extent as the original, unpurified cultures.The early readings yielded reproducible titers, which could be used for analysis of antigenic variation. Prime antigenic variants, of broader antigenic constitution than their non-prime relatives, were found among the Coxsackie B 2, B 3, and B 4 strains that were tested. These prime strains (e. g., B. V. A. 96- B2; Stevens - B 3, and Burrier or J. V. B. - B 4) were found to be antigenically broader than the prototype strains (Ohio 1 - B 2, Nancy - B 3, Powers or Texas 13 - B 4) generally used for the preparation of diagnostic antisera. The broader antigenicity of the prime variant was also present in plaque-purified progeny.Aided by grants from The National Foundation, Inc.The work reported here was carried out in 1957–1958 during Dr.Wigand's tenure of a fellowship in the Cincinnati Laboratory.     

Activity of trimethoprim/ sulfamethoxazole plus polymyxin B against multiresistantStenotrophomonas maltophilia

The inhibitory activity of eight antibiotics and the inhibitory and bactericidal activities of combinations of trimethoprim/sulfamethoxazole (TMP/SMX) plus three fixed concentrations of polymyxin B (0.01 g/ml, 0.1 g/ml and 0.5 g/ml) against 30 multiresistant strains ofStenotrophomonas maltophilia were tested. Polymyxin B at 0.01 g/ml modified the inhibitory activity of TMP/SMX against only 40% of strains. At 0.1 g/ml and 0.5 g/ml, polymyxin B enhanced the inhibitory activity of TMP/SMX activity against all strains. Polymyxin B enhanced the bactericidal activity of TMP/SMX only at concentrations near the minimum inhibitory concentration of polymyxin B alone.     

Measurement of β-glucuronidase in effluent of perifused alveolar macrophages challenged with chemically modified chrysotile asbestos

Chrysotile asbestos has been implicated with lung disorders, notably fibrotic lesions and cancer. In vitro, chrysotile fibers are cytotoxic to lung macrophages and stimulate the release of inflammatory mediators. Reports to the effect that chemical modifications of asbestos fibers reduce their cytotoxic and inflammatory potential initiated the present study of three fiber modifications. The cytotoxic and inflammatory effects of magnesium-leached chrysotile, POCL₃-treated chrysotile, and CaO-treated chrysotile were studied in a perifused rat alveolar macrophage culture system, relative to untreated fibers. Natural Canadian chrysotile (UICC B) caused dose-dependent cell mortality and clumping. The release of-glucuronidase (-Glu), a lysosomal enzyme, was also dose dependent. Rhodesian chrysotile (UICC A) caused similar cytotoxic and inflammatory effects. However, magnesium-leached chrysotile was less cytotoxic (39% less) and had a lesser clumping capacity (31% less) than untreated chrysotile. Total secretion of-Glu elicited by magnesium-leached chrysotile was reduced by 43% from the untreated sample, but kinetic monitoring indicates that this reduction in inflammatory potential is only significant during the first 12 h of an 18-h culture period. POCl₃ treatment of chrysotile fibers produced differing effects depending on the length of the fibers under study. Treating fibers with a mean length of 8 m produced a secretion pattern similar to that produced by acid leaching. The total output for the treated sample was 44% lower than with untreated chrysotile; the difference was only significant during the first 12 h of perifusion. Cell mortality and aggregation were not reduced in any important way with POCl₃ treatment of these longer fibers. When ultra-short fibers (mean length=0.8 m) were treated with POCl₃, the total decrease in-Glu output was equal to 41%, and the release of enzyme was significantly lower during the whole 18-h experiment. Cell aggregation was not appreciably affected, but cell mortality was significantly lower than for untreated fibers. CaO treatment did not alter the cytotoxic (cell death and aggregation) or inflammatory (-Glu release) effects of chrysotile asbestos. These results suggest that chemical modifications affecting the integrity of the surface magnesium and/or the polarity of the surface charge of chrysotile can reduce to some extent the cytotoxic and inflammatory properties of this type of asbestos.     

Possible involvement of microtubules in platelet-activating factor-induced increases in microvascular permeability in vitro

The blood vessels of the rat small intestine were perfused in vitro with a gelatin-containing physiological salt solution (GPSS). The addition of platelet-activating factor (PAF, 5M), podophyllotoxin (50M), colcemid (50M), or nocodazole (50M) to the GPSS for 5 min caused an increase in vascular permeability. This was manifested as an increased trapping of circulating colloidal carbon (CC) within the walls and was assessed using semiautomated image analysis. Pretreatment for 10 min with taxol (5M) in the perfusate significantly reduced the permeability-enhancing effects of all four agonists. Since podophyllotoxin, colcemid, and nocodazole are all microtubule-disrupting agents, and since taxol is a microtubule-stabilizing agent, these results suggest that microtubules are involved in the response of the microvessels to PAF. An explanation based on tensegrity or force-counterbalance is put forward to account for these findings.     

Altered synthesis of interferon-γ and expression of interferon-γ receptor by peripheral blood mononuclear cells from patients with IgA nephropathy and non-IgA proliferative glomerulonephritis

Previously we reported disease-specific interaction between interferon- (IFN-) and interleukin-4 (IL-4) in patients with IgA nephropathy (IgAN), suggesting the existence of unusual T cell behavior in this disease. In the present study, we investigated characteristic synthesis of interferon- (IFN-) and expression of IFN- receptor (IFN-R) in the peripheral blood mononuclear cells (PBMC) from patients with IgAN and other chronic proliferative glomerulonephritis (PGN). Heparinized peripheral blood samples were obtained from 38 patients with chronic mesangial proliferative glomerulonephritis (CGN; including 24 with IgA nephropathy) and 20 healthy controls. PBMC were isolated by gradient centrifugation and fragments were cultured in Iscove's modified Dulbecco's medium (IMDM) supplemented with 10% fetal calf serum (FCS) for 72 hr. IFN- concentrations in supernatants were evaluated by the enzyme-linked immunosorbent assay (ELISA). Other parts of PBMC pellets were reacted with anti-human IFN-R monoclonal antibody and FITC-labeled anti-mouse second antibody for analysis of IFN-R expression on these cells by FACScan. The remaining PBMC were fractionated into CD4⁺ T cells, CD8⁺ T cells, B cells, NK, cells and macrophages using the MACS cell sorting system. The isolated cells were evaluated for IFN- or IFN-R mRNA expression by the semiquantitative RT-PCR method.In vitro IFN- synthesis was enhanced in patients with CGN, and NK cells were revealed to be responsible for such enhancement. On the other hand, the expression of IFN-R on macrophages was suppressed in CGN patients. These results suggest that impairment of regulation of the IFN- system might be involved in the development of CGN.     

Isolation of the Bα and Bβ mating-type loci of Schizophyllum commune

The B mating type of the basidiomycete fungus, Schizophyllum commune is determined by two, tightly linked, multi-specificity (also called multi-allelic) loci: B and B. A plasmid library was used in DNA-mediated transformation to obtain transformants that displayed B-directed development. Plasmids that conferred B1 and B1 mating-type specificities were rescued from the transformants. Fragments of DNA from each plasmid hybridized to genomic DNA from the strain used to make the plasmid library; however, they did not hybridize, or hybridized only weakly, to genomic DNA from strains with mating-type specificities different from B1 or B1. The cloned fragments are presumed to correspond to active regions of each B mating-type locus.     

Modulation of hematopoietic colony formation of stem cells in peripheral blood by anti-TGF-β in patients with severe immunosuppression

Summary The influence of transforming growth factor- (TGF-) on hematopoiesis has been evaluated by adding blocking antibodies against TGF- to colony forming assays (CFU-c). When optimum concentrations of recombinant growth factors, granulocyte-macrophage colony stimulating factor (GM-CSF), and interleukin-3 (IL-3) were added to stem cells from the peripheral blood of healthy individuals and certain patients with tumors or HIV infection, the anti-TGF- capable of blocking 5 ng/ml of active TGF- had no significant influence on erythroid or myeloid colony formation. However, in certain immunosuppressed individuals, anti-TGF- resulted in a significant decrease of erythroid colony formation and slight suppression of myeloid colony formation. The significant inhibition of hematopoiesis by plasma of HIV patients could be due to the presence of active forms of TGF-. The results of the blocking experiments are consistent with the concept that TGF- in low concentrations is essential for erythropoiesis and myelopoiesis but that higher levels of TGF- primarily inhibit erythropoiesis in vitro. TGF- serves as a coordinating factor when efficient recruitment of granulocytes and monocytes is more essential than erythropoiesis and stem cell growth.Abbreviations BFU-E burst forming unit-erythroid - CFC colony forming cells - CFU-GEMM colony forming unit-granulocyte/erythroid/macrophage/megacaryocyte - CFU-GM colony forming unit-granulocyte/macrophage - EPO erythropoietin - GM-CSF granulocyte/macrophage-colony stimulating factor - HIV human immunodeficiency virus - IL-1 interleukin-1 - IL-3 interleukin-3 - IMDM Iscove's Modified Dulbecco's medium - PBS phosphate buffered saline - TGF- transforming growth factor- - TNF- tumor necrosis factor-     

Untersuchungen Mit J131-Markiertemβ-Globulin Zur Frage Der Abstammung Der Liquoreiweisskörper

Zusammenfassung Die Abstammung der-Globuline im Liquor wurde bei 20 Fällen mit den verschiedensten neurologischen Erkrankungen untersucht. — Die spezifische Aktivität der-Globuline war bei normalen und pathologischen Liquors ausnahmslos niedriger als im Serum. Es treten demnach nur einzelne Serum--Globuline in den Liquor über, ein verschieden großer Anteil der Liquor--Globuline wird im Liquorraum gebildet. Die-Fraktion im Liquor besitzt einen Serumanteil, von dem die liquoreigenen oder auch cerebrogenen-Globuline unterschieden werden können. Beziehungen zwischen der Höhe des liquoreigenen-Globulinanteils zu einzelnen Krankheitsgruppen waren nicht herzustellen. Es ließ sich aber zeigen, daß eine Erhöhung des elektrophoretisch ermittelten relativen-Globulingehaltes im Liquor bei pathologischen Fällen nicht — wie bisher angenommen wurde — mit einer Zunahme des cerebrogenen Eiweißes einherzugehen braucht. — Die Bedeutung des liquoreigenen-Globulins ist noch unbekannt, auch ist es nicht möglich zu entscheiden, welche einzelnen Proteine innerhalb der-Fraktion im Liquorraum entstanden sind oder aus dem Serum stammen.Mit Unterstützung der Deutschen Forschungsgemeinschaft.     

A T cell/B cell/epithelial cell internet for mucosal inflammation and immunity

Conclusions Mucosal immune responses are strongly regulated by CD4⁺ T cells and their derived cytokines. In this regard, IFN-^–/– mice (i.e., which lack Th1 and have elevated Th2 cells) showed strong mucosal Th2-type responses together with S-IgA production, while IL-4^–/– (e.g., dominant Th1 and lack of Th2 cells) mice had impaired mucosal Th2 and IgA responses following oral delivery of TT and CT. However, when rSalmonella or radenovirus were used for antigen delivery, significant levels of mucosal IgA responses were induced in both IFN-^–/^– and IL-4^–/^– mice. The choice of the antigen delivery system which leads to optimal Th and B cell interactions are important for the induction of effective IgA responses, even in situations where the immune system is compromised. It is clear that Th2-type cytokines are important in mucosal IgA responses; however, other cytokine combinations can compensate for mucosal immunity in situations in which Th2 cell responses are absent. Mucosally induced tolerance may be one approach to prevent several systemic immune disorders; however, the mechanism of this phenomenon still needs to be elucidated. Our recent findings have suggested that IFN- may play an important role in induction of systemic unresponsiveness since oral tolerance was not induced in IFN-^–/^– mice.Our studies as well as those of others indicated that at least two phases of a triad of cell interactions are important for the mucosal immune system. First, it has been shown that epithelial cell-produced IL-7 and SCF and T cell-derived IL-2 are essential activation and growth signals for intestinal T cells. Second, our studies with TCR knockout mice have suggested that mucosal T cells also play a critical role in the regulation of mucosal IgA responses. Thus, a mucosal internet among T cells, T cells, and IgA B cells appear critical for mucosal homeostasis and for regulation of specific mucosal immune responses.     

The structure of a feline picornavirus and its relevance to cubic viruses in general

Summary Using the negative staining technique the pattern of subunits (capsomeres) on the surface of cubic viruses can be revealed as either white projections against a dark background (posimeres),e.g. adenoviruses, or as dark hollows surrounded by a lighter rim (negameres),e.g. reoviruses. A symmetrical pattern of 32 negameres has been demonstrated for some recently isolated feline picornaviruses and from an extension of these studies, based on radiographs of foam-rubber models, it is postulated that posimere or negamere formation may be obtained by relatively minor variation of a basic structure unit.     

Cytochemischer Nachweis von β-Glucuronidase und β-Acetylglucosaminidase bei Plasmocytom

Zusammenfassung In den Plasmazellen von 17 Patienten mit Plasmocytom und 30 Patienten mit normaler Plasmazellzahl oder reaktiver Plasmocytose, die als Vergleich dienten, wurden-Glucuronidase und-Acetylglucosaminidase mit cytochemischer Methodik bestimmt. Bei allen untersuchten Fällen von Plasmocytom war die-Glucuronidaseaktivität im Vergleich zu den Kontrollfällen deutlich gesteigert, die-Acetylglucosaminidaseaktivität war bei 13 von 15 untersuchten Patienten gering bis stark erhöht, bei 2 Patienten im Vergleich zu den Kontrollfällen nicht sicher verändert. In 6 von 10 parallel mit beiden Methoden untersuchten Plasmocytomen war die-Glucuronidaseaktivität stärker, in 1 Fall die-Acetylglucosaminidase, bei 3 Fällen waren die Resultate identisch.Die Ergebnisse stützen die früher geäußerte Ansicht, daß neoplastische Plasmazellen reichlich lysosomale Enzyme besitzen.

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Summary The activities of-glucuronidase and-acetylglucosaminidase have been demonstrated in the plasma cells of 17 patients with multiple myeloma and of 30 patients with normal plasma cells or reactive plasmacytosis by cytochemical methods. In all cases of multiple myeloma the activity of-glucuronidase was elevated as compared with non-neoplastic plasma cells, activity of-acetylglucosaminidase showed a slight to strong elevation in 13 out of 15 patients with multiple myeloma, a normal activity was seen in 2 patients. 10 cases of multiple myeloma were investigated with both methods: in 6 there was stronger activity of-glucuronidase, in 1 patient-acetylglucosaminidase showed the stronger reaction, in 3 cases both enzymes revealed the same pattern.These results support the view that neoplastic plasma cells contain a high degree of lysosomal enzymes.

     

TRP channels: a TR(I)P through a world of multifunctional cation channels

The transient receptor potential (TRP) family of ion channels comprises more than 50 cation-permeable channels expressed from yeast to man. On the basis of structural homology, the TRP family can be subdivided in to seven main subfamilies: the TRPC (Canonical) group, the TRPV (Vanilloid) group, the TRPM (Melastatin) group, the TRPP (Polycystin), the TRPML (Mucolipin), the TRPA (Ankyrin) and the TRPN (NOMP) family. The cloning and characterization of members of this cation channel family has exploded during recent years, leading to a plethora of data concerning TRPs in a variety of cell types, tissues and species. This paper briefly reviews the TRP superfamily and the basic properties of its many members as a readers guide in this Special Issue. Hopefully, a better understanding of TRP channel physiology will provide important insight into the relationship between TRP channel dysfunction and human diseases.     

Amygdalar inputs to ADH-secreting supraoptic neurones in rats

Summary Effects of amygdala stimulation on the discharge activity of antidromically identified supraoptic neurosecretory neurones were studied in male rats anaesthetized with urethane. Stimulation of the medial and the basal amygdala produced excitation or inhibition of discharge activity both in phasically firing (phasic) and in continuously firing (continuous) neurones. More phasic neurones were excited than were inhibited after medial amygdala stimulation. On the other hand, fewer continuous neurones were excited by stimulation of the either amygdala area than were inhibited. This difference of responsiveness between phasic and continuous neurones is statistically significant. Synaptic inputs to supraoptic neurosecretory neurones after amygdala stimulation were also observed in rats with a lesion of the stria terminalis. Supraoptic nucleus stimulation activated antidromically 14 of the 336 amygdala neurones tested. Since phasic neurones have been identified as ADH-secreting neurones, it is concluded that ADH-secreting neurones in the rat supraoptic nucleus receive predominantly excitatory synaptic inputs from the medial amygdala and these amygdalar synaptic inputs are mediated by pathways which are at least in part monosynaptic and are not included in the stria terminalis.Supported by the grants nos. 56440079, 56121007 and 56770057 from the Ministry of Education, Science and Culture, Japan     

The sensitivity to Zn2+ discriminates between typical and atypical mast cells

The effects of zinc gluconate have been studied on rat peritoneal mast cells and rat basophilic leukemia cells (RBL 2H3) stimulated by various secretagogues. The IC₅₀'s of zinc gluconate on peritoneal cells were (M)1.6, 1.9, 5.4 and 18 for ionophore A23187, phorbol 12-myristate 13-acetate, substance P and immunoglobulin E-antigen, respectively. Higher concentrations of zinc gluconate were required to inhibit histamine secretion from RBL 2H3 cells, i.e. 12 M (ionophore A23187) and 140 M (immunoglobulin E-antigen). Zinc gluconate (10^–4 to 10^–3 M) also inhibited the IgE-dependent contraction of guinea pig trachea but was unable to affect that induced by exogenous histamine. These results suggest that zinc gluconate acts intracellularly and is selective of typical or connective tissue mast cells.     

Biophysical studies of teschen disease virus (Talfan strain)

Summary Studies have been made of the heterogeneity of infectivity and CFA in Teschen virus (Talfan strain) suspensions. Most of the infectivity was contained in two components of densities 1.46 gm./ml. and 1.35 gm./ml. The physical, chemical and immunological properties of these components have been compared. It was possible, however, to convert a large proportion of 1.46 component to 1.35 component by treating the 1.46 component with sodium dodecyl sulphate. This would indicate that the 1.46 component was a complex formed between the infective particles and cellular debris.Further studies on the growth characteristics and electron microscopy of the virus have been made.     

Effects of Age and Experience on Mating Activity in the Sibling Species Drosophila pavani and Drosophila gaucha

The effects of age and experience on sexual activity and on intra- and interspecific discrimination were studied in two sibling species of the mesophragmatica group, Drosophila pavani and Drosophila gaucha. Sexual activity of a total of 2970 individual couples of the same or of both species was observed at two ages: 10 days, (young inexperienced) and 18-20 days (old, either inexperienced or experienced, if either the male or the female had copulated previously). In the 1186 (39.97%) pairs that mated, the latency to copula and duration of copula were registered. Age has a different effect in both species: young Drosophila pavani and old Drosophila gaucha females are less receptive to males of either species of the corresponding age. The receptivity of females is also reflected in heterospecific matings, as Drosophila gaucha males increase their mating activity with age. In both species, female receptivity decreases with experience, whereas mating activity of males increases with experience, especially that of Drosophila gaucha toward heterospecific females. Drosophila pavani females take longer to mate than those of Drosophila gaucha. In both species old males tend to mate faster, whereas experience increases the latency to mating in females and decreases it in males. Both species differ significantly in the duration of copula. It is longer in Drosophila pavani than in Drosophila gaucha and is determined mainly by the male. The duration of copula increases with age, especially in Drosophila pavani females, whereas it is reduced in males of the same species.     

Isoenzymes of γ-glutamyl transpeptidase in liver diseases

Summary A new method for the separation of isoenzymes of-glutamyl-transpeptidase is described, using electrophoresis on acetate cellulose gel and a developing solution composed by-glutamyl-naphthylamide, and a colored diazonium compound.The method permits the separation of up to four different isoenzymes, which we called-GT₁,-GT₂,-GT₃,-GT₄, the first two showing an electrophoretic migration similar to that of ₁- and ₂-globulins and the other two to that of-globulins.The present technique has proved its usefulness in detecting isoenzymes in serum with values of total-glutamyl-transpeptidase higher than 80 U/L.The application of this method in 52 patients with different types of biliary obstruction and hepatocellular damage has shown that it provides new possibilities in differential diagnosis.     

Intrakranielle und intraspinale Blutungen unter Behandlung mit Cumarinderivaten

Summary From 1978–1986, 63 patients (48–79 years) under coumarin derivatives had to be hospitalized neurosurgically because of intrcranial or intraspinal bleedings. This corresponds to a twelvefold increased risk compared to the untreated people. The male/female ratio was 1.5. At the time of the bleeding there was no true indication for anticoagulation in at least 60% of the patients. 80% with coma on admission died. Only for 2/7 with an intraspinal hemorrhage the outcome was better than paraplegic. Women proved to have a better chance of survival. — There is a need for more concise indications for chronic anticoagulation.

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Abkürzungen CT Röntgen-Computertomographie - Cumarine für Cumarinderivate; hier zu 97% Phenprocoumon - ZNS-Blutung nur der Kürze wegen fürbegrifflich korrekt: intrakranielle und intraspinale Blutung Meinem Lehrer, Herrn Dr. med. Czeslaw Andrzejewski, zum 70. Geburtstag gewidmet!     

An hypothesis regarding the cortical mechanisms of operative memory

Investigations of the neuronal activity of the cerebral cortex of monkeys during the performance of a delayed spatial choice made it possible to formulate an hypothesis regarding the neuronal systems providing for operative memory. One system functions on the principle of relay race-reverberation transmission of information. During the action of a sensory signal a population of spatially selective sensory neurons is excited. By the delay period (operative memory) this information is transmitted to a population of memory neurons. The delay period is quantized in time segments in the course of which individual populations of cells are involved in relays in the reverberation activity. Each of these populations comprises a neuronal trap in which the excitation circulates for 1.5–2 sec. At the end of the delay period switching of the excitation to a different population of cells takes place, which are associated with the preparation of a goal-directed movement (the neurons of the motor programs). Another system of neurons assures the reliability of the transitional phases of the above-named processes, specifically: 1) of the switchings of information from the sensory neurons to the memory neurons and subsequently to the neurons of the motor programs; 2) the reflection of the entire period of operative memory without relay race-reverberation; and 3) the preservation of the signal information in the activity of a unified neuronal population right up to the moment of the performance of the goal-directed movement. The above-designated systems are represented variously in the associative (frontal and parietal) zones of the neocortex.Translated from Zhurnal Vysshei Nervnoi Deyatel'nosti imeni I. P. Pavlova, Vol. 41, No. 6, pp. 1088–1093, November–December, 1991.