Showing papers by "University of Zurich published in 1980"

Synthesis in E. coli of a polypeptide with human leukocyte interferon activity

Abstract: Double-stranded cDNA prepared from the 12S fraction of poly(A) RNA from interferon (IF)-producing human leukocytes was cloned in Escherichia coli using the pBR322 vector. One of the resulting clones had a 910-base pair insert which could hybridise to IF mRNA and was responsible for the production of a polypeptide with biological IF activity. Up to 10,000 units IF activity per g of cells was obtained from some clones.

The structure of one of the eight or more distinct chromosomal genes for human interferon- α

Abstract: The 12 Interferon (IFN)-related sequences detected in a human gene bank fall into not less than eight distinct classes, indicating that there are at least eight IFN-related genes. Most, if not all, of these direct the synthesis of an IFN in Escherichia coli. The sequence of one chromosomal gene and its flanking regions was identical to that deduced for the cDNA corresponding to IFN-αl mRNA. No evidence was found for the existence of an intron, in either the coding or the non-coding segments of the gene.

Hormone families: pancreatic hormones and homologous growth factors

Abstract: The growing realization that biologically active polypeptides can be grouped in families, the members of which show structural and functional relatedness, is illustrated by the four families which are represented in the pancreas by the hormones insulin, glucagon, somatostatin and pancreatic polypeptide.

At least three human type alpha interferons: structure of alpha 2

Abstract: The sequence of a human leukocyte-derived complementary DNA (cDNA), Hif-2h, which directs the formation in Escherichia coli of a polypeptide, IFN-alpha 1, with interferon (IFN) activity has been described. A second IFN cDNA, Hif-SN206, which also elicits synthesis of a biologically active IFN, IFN-alpha 2, is described in this article. Whereas IFN-alpha 2 is twice as active on human as on bovine cells, IFN-alpha 1 is 10 to 20 times more active on bovine than on human cells. As deduced from the cDNA's, the messenger RNA's for the two IFN's differ in length and in 20 percent of the nucleotides; the mature IFN polypeptides differ in 17 percent of the amino acids. Both IFN-alpha 1 and IFN-alpha 2 differ from the lymphoblastoid IFN described by others. Therefore, at least three different IFN-alpha genes are expressed in man; studies on genomic DNA reveal the presence of at least eight IFN-related genes.

On some linear and nonlinear eigenvalue problems with an indefinite weight function

Abstract: (1980). On some linear and nonlinear eigenvalue problems with an indefinite weight function. Communications in Partial Differential Equations: Vol. 5, No. 10, pp. 999-1030.

Human leukocyte and fibroblast interferons are structurally related.

Abstract: The coding sequences of the dDNAs of cloned human leukocyte interferon I and human fibroblast interferon show homologies of 45% at the nucleotide and 29% at the amino acid level. We conclude that the two genes were derived from a common ancestor.

Selective retrograde labeling indicating the transmitter of neuronal pathways

Abstract: A number of tritiated transmitter related compounds—amino acids and biogenic amines—were injected into the rat caudoputamen or substantia nigra in order to test (1) for the occurence of autoradiographic perikaryal labeling, (2) for a selectivity of perikaryal labeling relating certain compounds to certain pathways, and (3) for the relation of perikaryal labeling to known transmitter specificities of the systems involved. Perikaryal labeling was observed after injection of some but not all of the substances used and was best explained by retrograde labeling in pathways projecting to the injection sites. Six hours after injection of high concentrations of tritiated transmitter into the terminal area, perikaryal labeling was observed: (A) in substantial nigra compacta (A9), A10 (rostral) and A8 (all heavy), and in n. raphe dorsalis (light) after [3H]-dopamine and [3H]-norepinephrine injection into caudoputamen; (B) same pattern as in A, but heavy in n. raphe dorsalis after [3H]-serotonin injection into caudoputamen; perikaryal labeling absent in cortex and thalamus after injection of substances mentioned in A and B; (C) only in substantia nigra compacta (minimally) after [3H]-GABA injection into caudoputamen; (D) in cerebral cortex and thalamus but not in substantia nigra, A10, A8, nor in n. raphe dorsalis after injection of [3H]-D-aspartate into caudoputamen; (E) in the rat caudoputamen but not in n. raphe dorsalis after [3H]-GABA injection into substantia nigra; (F) in n. raphe dorsalis but not in caudoputamen after [3H]-serotonin into substantia nigra. These results indicated, indeed, a certain selectivity—partly related to transmitter specificity—for perikaryal labeling patterns. As a method, transmitter specific retrograde tracing could be useful in pathways with dopamine-, serotonin-, and GABA-mediated synaptic transmission.

Copper metallothionein, a copper-binding protein from Neurospora crassa

Abstract: Copper is an essential constituent of many proteins which participate in biologically important reactions. In contrast to iron, where different metal storage and transport proteins have been extensively characterised, the existence of copper proteins serving such functions is still a matter of controversy. Studies on the biosynthesis of tyrosinase from Neurospora crassa with respect to the copper status of this fungus have shown that this organism accumulates copper with the concomitant synthesis of a small molecular weight copper-binding protein. This protein is now shown to have a striking sequence homology to the zinc- and cadmium-containing metallothioneins from vertebrates. Growth experiments suggest that this molecule fulfills several important physiological functions in this organism such as copper storage, copper detoxification and provision of copper for tyrosinase.

Meningiomas of Basal Posterior Cranial Fossa

Abstract: A review of the clinical findings and operative course in patients with clivus and cerebellopontine angle meningiomas is warranted because of the rarity of these tumors, their lethal nature if left unoperated, and the morbidity and mortality which have often followed operation. A new situation exists with CT: early diagnosis!

Light and electron microscopic studies on the effect of praziquantel on Schistosoma mansoni, Dicrocoelium dendriticum, and Fasciola hepatica (Trematoda) in vitro.

Abstract: The fine structure of the tegument of three trematode species,Schistosoma mansoni, Dicrocoelium dendriticum, andFasciola hepatica, was studied by means of light scanning (SEM) and transmission electron microscopy (TEM) after in vitro exposure to 0, 1,10, and 100 μg/ml of the anthelmintic praziquantel for 5, 15, 30, and 60 min. InS. mansoni andD. dendriticum the resulting vacuolization of the tegument was confined to numerous small areas scattered all over the surface of the parasites and this finally led to the disruption of the apical tegumental layer. No changes were found in the tegument ofF. hepatica after treatment with praziquantel.

Specialized photoreceptors at the dorsal rim of the honeybee's compound eye: Polarizational and angular sensitivity

Abstract: 1. The spectral, polarizational and angular sensitivities of photoreceptor cells In the honeybee compound eye are examined by intracellular electrophysiological recordings. The specific aim of this paper is to compare the characteristics of receptor cells in the anatomically specialized dorsal rim area of the eye (containing non-twisted retinulae which are composed of 9 long receptor cells) with those of receptors in the remainder of the eye (containing twisted retinulae which are composed of 8 long cells and 1 short cell). 2. The direction of the optical axis for each cell investigated was determined within a coordinate system of space that takes into consideration the head position of the flying bee. All the cells studied (except those in the frontal part of the eye) looked upwards in directions close to the zenith (Fig. 2). 3. The UV-cells of the dorsal rim area exhibit high polarizational sensitivities (PS). The actual PS values depend on the amount of coupling between UV- and green-cells (Fig. 5a): UV-cells having relative green-sensitivities of >10% exhibit an average PS of 3.8; if the green-sensitivity is <10% it is 5.6 and rises to more than 10 for cells which either do not respond or hyperpolarize to green light. The overall average PS is 6.6. In marked contrast to this finding, most UV-cells in the remainder of the eye (in twisted retinulae) have PS <2.0 (Fig. 5b). 4. Polarizational sensitivities of green-cells are only slightly higher in the dorsal rim area (PS =1.8) than in the other parts of the eye (PS=1.3) (Fig 5c, d). 5. By measuring the direction of maximal sensitivity to the e-vector of linearly polarized light (Φmax), two populations of UV-receptors have been found in the dorsal rim area; theirΦmax values differ by 90° (Fig. 6). 6. Angular sensitivity functions having unconventional shapes are measured in most receptors of the dorsal rim area. They show a relatively narrow peak in the center and a wide, flat brim in which the average sensitivity decreases from 8% at 7° off axis to 2% at 30° (Fig. 3b, d; 7). If UV-cells having this type of visual field are tested with off-axial (20–30°) stimuli, PS is still high andΦmax is the same as for on-axial stimulation. Thus, the UV-cells of the dorsal rim area are wide-field e-vector analyzers. Apparently, the wide visual fields are caused by corneal specializations in that part of the eye. Control experiments in other parts of the eye confirm the narrow visual fields as they have been described by former authors (Fig. 3a, c). 7. The results are discussed in the light of recent behavioral and anatomical investigations on polarization vision. It is concluded that e-vector detection in the honeybee is performed mainly by the UV-receptors of the dorsal rim area.

Myosin types in human skeletal muscle fibers.

Abstract: By combining enzyme histochemistry for fiber typing with immunohistochemistry for slow and fast myosin a correlation between fiber type and myosin type was sought in human skeletal muscle. Fiber typing was done by staining for myofibrillar ATPases after preincubation at discriminating pH values. Myosin types were discriminated using type specific anti-rabbit myosin antibodies shown to cross-react with human myosin and were visualized by a protein A-peroxidase method. Type I fibers were shown to contain slow myosin only, type IIA and IIB fibers fast myosin only, and type IIC fibers both myosins in various proportions. When muscle biopsies from well-trained athletes were investigated essentially the same staining pattern was observed. However, rarely occurring type I fibers with high glycolytic activity were detected containing additional small amounts of fast myosin and occasional type IIA fibers had small amounts of slow myosin. Based on the observation of various fiber types in which slow and fast myosin coexist we propose a dynamic continuum of fibers encompassing all fiber types.

Blue field entoptic phenomenon and blood velocity in the retinal capillaries.

Abstract: The blue field entoptic phenomenon consists of the perception of one’s own leukocytes (white blood cells) flowing in the macular capillaries of the retina. A method has been developed for determining the speed of the leukocytes. In this method, the motion of the leukocytes is simulated on a screen by means of a minicomputer system. The subject is instructed to match the motion of the simulated white blood cells with that of his own leukocytes. For this, he can adjust the number and the maximum and minimum speeds of the simulated particles. Measurements in five young subjects with normal fundi indicate that the speed of the leukocytes in the macular capillaries of the retina is pulsatile. Minimum and maximum speeds are approximately 0.5 and 1 mm/s.

Host gene influences sensitivity to interferon action selectively for influenza virus

Abstract: Several examples of genetically determined resistance to different viruses have been studied in mice1. Inborn resistance due to the allele Mx in A2G mice may be characterised as follows: resistance is specific for members of the orthomyxo family (influenza virus)2; it is expressed in different organs and cells2–6; and it is independent of a functioning immune system3,4,7. The only means of rendering resistant mice fully susceptible to influenza virus has been treatment with potent anti-interf eron serum8, indicating that interf eron is important in resistance. Interf eron is generally thought to inhibit the multiplication of all animal viruses relatively indiscriminately. Therefore, it had seemed unlikely that interferon was involved in this resistance, as A2G mice were selectively resistant to influenza virus albeit as sensitive as control mice to several other viruses4. There are, however, examples in which the genetic control of the production of interferon or the sensitivity to interferon action is expressed selectively for a given virus. Thus, De Maeyer and coworkers have shown that four different If loci control the amount of circulating interferon produced after injection of mice with Newcastle disease virus (NDV)9, mouse mammary tumour virus10, or Sendai virus (personal communication). Hanson et al.11 found that cultures of cells from C3H RV mice, resistant to Arbo B virus infection, were much more susceptible to the inhibitory effect of interferon when tested with Arbo B viruses than cultures taken from susceptible C3H mice. We present here results, showing that cultures of macrophages from mice resistant to orthomyxoviruses (Mx positive) can be protected by much smaller amounts of interferon than are necessary to protect cultures from susceptible mice when these cultures are infected with influenza virus; whereas no difference in sensitivity to interferon is observed when cultures are infected with vesicular stomatitis virus (VSV) or encephalomyocarditis virus (EMC). We believe that these results showing a genetic control of sensitivity to interferon action specific for a given virus are related to the in vivo resistance of A2G mice to influenza virus. If applicable to man, these results may also be of importance in understanding individual variations in sensitivity to viral infections.

Male assessment of female choice in hamadryas baboons

Abstract: 1 The study investigates the conditions under which a hamadryas male \lsrival\rs respects a pair consisting of a male \lsowner\rs and his female rather than fighting the owner and attempting to appropriate the female. Two types of laboratory experiments were carried out on a colony of six males and six females: (a) choice tests that yielded a score of preference of each female for each male and of each male for each female, and (b) tests that measured the tendency of the rival to respect a pair in a given triad. The following results were obtained: (1) The respect of the rival was not correlated with the preference of the owner or of the rival for the particular female. (2) The respect of middle- and low-ranking rivals was positively correlated with the preference of the female for the owner. The two males highest in rank did not adhere to this strategy. 2 These results are functionally interpreted in terms of an asymmetric \lspayoff\rs of the female to the males. Under a given dominance relationship (or asymmetry of resource holding potential) between the two males, a female with a strong preference for her present owner is too costly a prize for the rival in terms of herding effort and the risk of losing her again. However, if a rival is informed that the female will not choose her present owner, his attack may temporarily free her from the owner's herding and permit her to exert her choice in favor of the rival. The strategy seems particularly adaptive in males that cannot play out their superior rank. The causal interpretation is that baboons may be capable of assessing aspects of a relationship among two other members of their group.

The influence of high pressure freezing on mammalian nerve tissue

Abstract: Vitrification of biological specimens in liquid nitrogen can be achieved under high pressure (2,100 bars). This procedure obviates the use of aldehyde fixation and cryoprotection (glycerol). The present work demonstrates its applicability to the freeze-etching of mammalian brain tissue. Freeze-fracture replicas from rat cerebellar cortex and subfornical organ prepared by this method are compared to conventionally processed material using aldehyde fixation, glycerination and freezing with Freon. The formation of large ice crystals is prevented in tissue blocks up to 0.5 mm thick; deep etching is markedly enhanced. Cytoplasmic microstructures such as mitochondrial cristae, microtubules and microfilaments, are readily observable against a finely granulated cytosol matrix. An additional advantage is the combined application with freeze-substitution.

Periodic solutions of asymptotically linear Hamiltonian systems

Abstract: We prove existence and multiplicity results for periodic solutions of time dependent and time independent Hamiltonian equations, which are assumed to be asymptotically linear. The periodic solutions are found as critical points of a variational problem in a real Hilbert space. By means of a saddle point reduction this problem is reduced to the problem of finding critical points of a function defined on a finite dimensional subspace. The critical points are then found using generalized Morse theory and minimax arguments.

Sea urchin histone mRNA termini are located in gene regions downstream from putative regulatory sequences

Abstract: S1 nuclease mapping of the Psammechinus miliaris embryonic histone mRNAs locates the 5' termini in or adjacent to a short sequence homology (5'pyCATTCpu3') downstream from the putative RNA polymerase II regulatory sequence (5'TATAAATA3') or related sequences. The 3' termini map just after a sequence containing GC-rich hyphenated dyad symmetry, a feature of most known terminator sequences.

Treatment of abdominal angina with percutaneous dilatation of an arteria mesenterica superior stenosis

Abstract: Percutaneous transluminal dilatation of an atherosclerotic stenosis of the superior mesenteric artery was done in a 65-year-old woman with abdominal angina. The patient was relieved of abdominal pain immediately after the dilatation.

Conditions and pathological features of rapidly destructive, experimental periodontitis in dogs.

Abstract: In order to analyze the conditions for rapidly destructive periodontitis and to describe the early histopathological changes and bone degradation, periodontitis lesions were produced in five male Beagle dogs, 8 to 12 months of age. Cotton floss ligatures were placed around the crowns of upper and lower third and fourth premolars for periods of 4, 7, 14, 21 days. The buccal gingival tissues, being slightly inflamed initially, were clinically scored for various symptoms of inflammation. Block biopsies of premorlars and the adjacent buccal periodontal tissues were taken and processed for light and electron microscopy. Depending on the ligature position in relation to the gingival margin (above, at, deep below) at the day of biopsy harvest, three groups of selected biopsies were formed, and randomly selected sections of these were used for various histometric measurements, for stereological estimation of the size and composition of the connective tissue infiltrate and the osteoclast density, and for general histopathological evaluation. The resulting data and observations implied that (1) onset and maintenance of this periodontitis lesion depend on subgingival ulceration, (2) rapid bone desstruction is the result of osteoclast activity stimulated by acute inflammation, and (3) bone degradation occurs independently of the loss of collagen fiber attachment and the apical migration of the junctional epithelium.

Ubiquitous and gene-specific regulatory 5′ sequences in a sea urchin histone DNA clone coding for histone protein variants

Abstract: The DNA sequences of the entire structural H4, H3, H2A and H2B genes and of their 5' flanking regions have been determined in the histone DNA clone h19 of the sea urchin Psammechinus miliaris In clone h19 the polarity of transcription and the relative arrangement of the histone genes is identical to that in clone h22 of the same species The histone proteins encoded by h19 DNA differ in their primary structure from those encoded by clone h22 and have been compared to histone protein sequences of other sea urchin species as well as other eukaryotes A comparative analysis of the 5' flanking DNA sequences of the structural histone genes in both clones revealed four ubiquitous sequence motifs; a pentameric element GATCC, followed at short distance by the Hogness box GTATAAATAG, a conserved sequence PyCATTCPu, in or near which the 5' ends of the mRNAs map in h22 DNA and lastly a sequence A, containing the initiation codon These sequences are also found, sometimes in modified version, in front of other eukaryotic genes transcribed by polymerase II When prelude sequences of isocoding histone genes in clone h19 and h22 are compared areas of homology are seen to extend beyond the ubiquitous sequence motifs towards the divergent AT-rich spacer and terminate between approximately 140 and 240 nucleotides away from the structural gene These prelude regions contain quite large conservative sequence blocks which are specific for each type of histone genes