Showing papers by "University of Zurich published in 1983"
TL;DR: It is proposed that this tissue-specific enhancer contributes to the activation of somatically rearranged immunoglobulin variable region genes and possibly to abnormal expression of other genes (e.g. c-myc) that become translocated to its domain of influence.
1,285 citations
TL;DR: Using the nonscalar complexity in k, the complexity of single power sums, single elementary symmetric functions, the resultant and the discriminant as root functions are determined up to order of magnitude.
473 citations
TL;DR: Cloned rabbit beta-globin genes, modified in vitro by restructuring or site-directed mutagenesis, were introduced into mouse 3T6 cells, and the resulting transcripts were analyzed by nuclease S1 mapping to find the first 109 bp preceding the cap site sufficed for maximal beta- globin transcription.
446 citations
TL;DR: The chimpanzees of the Tai National Park, Ivory Coast, use sticks and stones to open 5 different species of nuts, in spite of an unfavourable availability of the material in the forest.
Abstract: The chimpanzees of the Tai National Park, Ivory Coast, use sticks and stones to open 5 different species of nuts. In spite of an unfavourable availability of the material in the forest, the animals choose their tools adaptively. For cracking harder nuts, they use harder and heavier tools and transport tools more often and from farther away. Some aspects of the evolution of tool-use in primates are discussed.
360 citations
TL;DR: Serum concentrations of IGF II were normal in subjects with Type I diabetes but were somewhat depressed in those with Type II disease, and such levels do appear to identify patients at high risk for rapid deterioration of vision, and hence may be useful in selecting patients for more intensive or alternative forms of therapy.
Abstract: To determine whether two insulin-like growth factors (IGF I and IGF II) influence the course of diabetic retinopathy, we measured the concentrations of these factors in 80 adult patients with diabetes and in 62 control subjects. In seven patients with Type I diabetes and rapidly deteriorating vision as a result of proliferative and exudative retinopathy, the serum concentration of IGF I was 722 +/- 41 ng per milliliter (mean +/- S.E.M.), as compared with 381 +/- 48 ng per milliliter in 26 patients who had Type I diabetes without retinopathy or with less severe forms of it, and 302 +/- 15 ng per milliliter in the controls (P less than 0.001 for both comparisons). Serum concentrations of IGF II were normal in subjects with Type I diabetes but were somewhat depressed in those with Type II disease. Whether elevated serum concentrations of IGF I cause the accelerated development of retinopathy in some patients remains to be determined. Such levels do appear to identify patients at high risk for rapid deterioration of vision, and hence may be useful in selecting patients for more intensive or alternative forms of therapy.
302 citations
TL;DR: An infant with the campomelic syndrome presents at birth with spectacularly short and bowed femora and tibiae, and internal anomalies include frequent absence of olfactory bulbs and tracts and dilatation of cerebral ventricles, heart defects, hydroureter and hydronephrosis, renal hypoplasia, renal hyperplasia, and rarely renal cysts.
Abstract: We report 17 cases of the campomelic syndrome (CS) and a follow-up of one of the original patients of Maroteaux et al who is now 17 years old. Our review is based on 97 patients, including our own. An infant with the CS presents at birth with spectacularly short and bowed femora and tibiae. The initial chest radiograph confirms the diagnosis by demonstrating extremely small bladeless scapulae and hypoplastic pedicles of many thoracic vertebrae. Ossification of the sternal segments, pubis, talus, and knee epiphyses is also retarded. Usually the hips are dislocated and talipes equinovarus deformities are present. There is a small chondrocranium and a disproportionately large neurocranium. The bell-shaped chest, narrow superiorly, does not explain the degree of respiratory distress that soon ensues. Narrow airways from defective tracheo-bronchial cartilage can often be demonstrated on the radiograph, but micrognathia, retroglossia, cleft palate, hypoplastic lungs, and even CNS-based hypotonia contribute to the respiratory problem. Internal anomalies include frequent absence of olfactory bulbs and tracts and dilatation of cerebral ventricles, heart defects (PDA, VSD, stenosis of aortic isthmus), hydroureter and hydronephrosis, renal hypoplasia, renal hypoplasia, and rarely renal cysts.
274 citations
TL;DR: The typical rank (= maximal border rank) of tensors of a given size and the set of optimal bilinear computations of typical TensorRank are investigated and it is shown that for the size ( n, n, 3) with n odd, the complement of theSet of Tensors of maximal borderRank is a hypersurface.
259 citations
TL;DR: Although the animals were unable to suppress rapid changes in eye velocity due to activation of direct vestibulo-oculomotor pathways, they had retained their ability to discharge activity from the velocity storage mechanism, and animals had no difficulty in suppressing OKAN after flocculectomy.
Abstract: Optokinetic nystagmus (OKN), optokinetic after-nystagmus (OKAN), vestibular nystagmus and visual-vestibular interactions were studied in monkeys after surgical ablation of the flocculus and paraflocculus. After bilateral flocculectomy the initial rapid rise in slow phase eye velocity of horizontal and vertical OKN was severely attenuated, and maximum velocities fell to the preoperative saturation level of OKAN. There is generally little or no upward OKAN in the normal monkey, and upward OKN was lost after bilateral lesions. Unilateral flocculectomy affected the rapid rise in horizontal velocity to both sides. Consistent with the absence of a rapid response to steps of surround velocity, animals were unable to follow acceleration of the visual field with eye accelerations faster than about 3-5 degrees/s2. The slow rise in OKN slow phase velocity to a steady state level was prolonged after operation. However, rates of rise were approximately equal for the same initial retinal slips before and after operation. The similarity in the time course of OKN when adjusted for initial retinal slip, and in the gain, saturation level and time course of OKAN before and after flocculectomy indicates that the lesions had not significantly altered the coupling of the visual system to the velocity storage integrator or its associated time constant. When animals were rotated in a subject-stationary visual surround after flocculectomy, they could not suppress the initial jump in eye velocity at the onset of the step. Despite this, they could readily suppress the subsequent nystagmus. The time constant of decline in the conflict situations was almost as short as in the normal monkey and was in the range of the peripheral vestibular time constant. This suggests that although the animals were unable to suppress rapid changes in eye velocity due to activation of direct vestibulo-oculomotor pathways, they had retained their ability to discharge activity from the velocity storage mechanism. Consistent with this, animals had no difficulty in suppressing OKAN after flocculectomy. Visual-vestibular interactions utilizing the velocity storage mechanism were normal after flocculectomy, as was nystagmus induced by rotation about a vertical axis or about axes tilted from the vertical. Also unaffected were the discharge of nystagmus caused by tilting the head out of the plane of the response and visual suppression of nystagmus induced by off-vertical axis rotation. The flocculus does not appear to play an important role in mediating these responses. The data before and after flocculectomy were simulated by a model which is homeomorphic to that presented previously.(ABSTRACT TRUNCATED AT 400 WORDS)
254 citations
TL;DR: It is concluded that the clinical and biochemical expression of 11 beta-hydroxylase deficiency is variable, that hypertension in not directly related to deoxycorticosterone, and that, regardless of the intensity of the defect, there are patients in whom the 11 Beta-Hydroxylation of 17 alpha-hydroxyylated steroids only is impaired.
Abstract: Twenty five patients (10 males and 15 females) aged 0-23 yr with congenital adrenal hyperplasis due to 11 beta-hydroxylase deficiency were studied. They were divided into 13 classic (group A), and 12 mild (group B) patients. The patients of group A were diagnosed at a younger age and had more severe clinical symptoms (ambiguous genitalia in girls, pseudoprecocious puberty in boys). Two had neonatal salt wasting before treatment, and one gynecomastia. Seven had moderate to severe hypertension. Their mean 3 alpha,17,21-trihydroxy-5 beta-pregnan-20-one (THS) and 3 alpha, 21-dihydroxy-5 beta-pregnane-11,20-dione (THDOC) excretion was 14.2 +/- 4.1 and 7.2 +/- 4.2 mg/m2 . day, respectively. The patients of group B had mostly late onset of symptoms (hirsutism, amenorrhea in girls, pseudoprecocious puberty in boys, tall stature, and advanced bone age in both sexes). One boy had bilateral cryptorchidism. Four had moderate hypertension. In seven patients, THS (5.3 +/- 2.3 mg/m2 . day) and THDOC (3.9 +/- 0.5 mg/m2 . day) responded to ACTH. In five, only THS (4.3 +/- 1.1 mg/m2 . day) responded, but THDOC remained undetectable. It is concluded that the clinical and biochemical expression of 11 beta-hydroxylase deficiency is variable, that hypertension in not directly related to deoxycorticosterone, and that, regardless of the intensity of the defect, there are patients in whom the 11 beta-hydroxylation of 17 alpha-hydroxylated steroids only is impaired, and others in whom both the conversion of 17,20-dihydroxy-4-pregnene-3,20-dione and deoxycorticosterone are reduced.
241 citations
TL;DR: Bone loss was considerable; prednisone 25 mg on alternate days caused an average reduction in trabecular bone of 3.5% over one year, and Cortical bone was not significantly affected over the same period.
Abstract: Treatment with corticosteroids can produce osteoporosis. It is generally held that bone loss occurs when steroids are administered daily, but recent findings indicate that bone may also be lost on alternate day therapy. Cortical and trabecular bone, which may be affected differently, can be assessed independently, by quantitative computed tomography. This technique has been applied to the appendicular skeleton in following 20 patients with bronchial asthma during one year of chronic alternate day corticosteroid therapy. The trabecular bone loss was considerable; prednisone 25 mg on alternate days caused an average reduction in trabecular bone of 3.5% over one year. Bone loss was dose- and agedependent. Young patients on 50 mg/2 days lost up to 17% trabecular bone in one year. Cortical bone was not significantly affected over the same period.
239 citations
TL;DR: Bacillus subtilis was transformed with a hybrid gene in which the sequence encoding the alpha-amylase signal peptide was joined by a linker to the sequence encode mature human interferon alpha 2(IFN-alpha 2).
TL;DR: A model in which the Ribosomal spacer is a loading site for RNA polymerase I and spacer transcription is the driving force by which polymerase is delivered to the ribosomal gene promoter is proposed.
Abstract: The function of the Xenopus laevis ribosomal spacer has been studied in vivo and by microinjection of in vitro mutants into Xenopus oocytes. It is shown that the spacer directs specific RNA transcripts which most probably terminate upstream of the ribosomal genes and that it is able to modulate transcription of these genes. The data lead to a model in which the ribosomal spacer is a loading site for RNA polymerase I and spacer transcription is the driving force by which polymerase is delivered to the ribosomal gene promoter.
TL;DR: In this article, it was shown that general second order elliptic boundary value problems on bounded domains generate analytic semigroups on L.............. p, 1≦p < ∞.
Abstract: It is shown that general second order elliptic boundary value problems on bounded domains generate analytic semigroups onL
1. The proof is based on Phillips’ theory of dual semigroups. Several sharp estimates for the corresponding semigroups inL
p, 1≦p<∞, are given.
TL;DR: Only one of six point mutations of the sequence around one end of the larger of the introns of the rabbit β-globin gene seriously affects the normal removal of the intron and splicing of the gene.
Abstract: Only one of six point mutations of the sequence around one end of the larger of the introns of the rabbit beta-globin gene seriously affects the normal removal of the intron and splicing of the gene. That mutation converts a GT sequence, invariably found at the 5' end of introns, into an AT, which is no longer recognized as a signal for intron removal. Instead, three normally unused (cryptic) sites are used, leading to aberrant gene transcripts. One of the cryptic sites is an exception to the invariable GT sequence.
TL;DR: The results indicate that degeneration or dysfunction of cholinergic neurons in the medial septal area and possibly neocortex is an important characteristic of SDAT.
TL;DR: It is concluded that the homeostatic component of sleep regulation is morphologically and functionally distinct from the circadian component.
TL;DR: IGFs barely stimulated cell replication, but preferentially enhanced the differentiation of muscle cells, and myoblast fusion was favoured in the presence of IGF (or insulin), while acetylcholinesterase activity increased.
TL;DR: When compared in an ELISA with conventional reagents, the battery of monoclonal antibodies proved to be as sensitive as conventional polyclonal antibodies.
TL;DR: This review deals with the recent progress on the molecular structure of the enzyme from Neurospora crassa and the unique features of the binuclear active site copper complex involved in the activation of molecular oxygen and the binding of substrates.
Abstract: Tyrosinase is a copper containing monooxygenase catalyzing the formation of melanin pigments and other polyphenolic compounds from various phenols. This review deals with the recent progress on the molecular structure of the enzyme from Neurospora crassa and the unique features of the binuclear active site copper complex involved in the activation of molecular oxygen and the binding of substrates. The results of the spectroscopic properties of Neurospora tyrosinase will also be discussed in the light of the structural similarity of the copper complex in the oxygen binding hemocyanins.
TL;DR: The results demonstrate that mantids do indeed rely on binocular triangulation when estimating the distance of prey, and thus provide the first unequivocal evidence for stereoscopic vision in an invertebrate.
Abstract: Binocularity in insects is generally assumed to have the same function as in many vertebrates—the perception of depth. Evidence for this hypothesis stems from the observation that one-eyed dragonfly larvae, tiger beetles, praying mantids and water scorpions rarely catch prey1–5 but no definitive evidence is available. Depth perception and catching behaviour depend on visual attention and visual behaviour and it is difficult to assess what is impaired when one eye is occluded6. A more promising approach to studying the importance of binocular disparity is one that does not interfere with normal binocular vision, and allows potential monocular depth cues to be controlled carefully. These criteria were met in the present study by the use of prismatic lenses placed in front of the compound eyes of the praying mantis, thus creating a conflict between binocular disparity and monocular cues. The results demonstrate that mantids do indeed rely on binocular triangulation when estimating the distance of prey, and thus provide the first unequivocal evidence for stereoscopic vision in an invertebrate.
TL;DR: No significant difference in the affinity and number of muscarinic and nicotinic receptors was found in hippocampus, frontal, temporal and cingulate cortex between SDAT patients and non-neurological controls, however, some SDAT cases showed diffuse instead of laminar [3H]NMS labeling in cortical regions.
TL;DR: These results are consistent with a model for visual saccades in eye displacement coordinates, where the spatio-temporal recoding of horizontal eye movements is effected by long-lead burst neurons in the PPRF.
Abstract: The integrity of the paramedian pontine reticular formation (PPRF) is necessary for the generation of rapid eye movements. The main saccade-related population is of the burst type with latencies between 0 and 40 ms preceding a saccade, and they can be divided into medium- and long-lead burst neurons. Burst neurons have predominantly spatially coded movement fields in the rostral PPRF, while in the caudal PPRF they increase their burst strength in temporal coding approximately in the pulling directions of extraocular eye muscles (i.e. almost horizontal or vertical). Both neuronal populations have ipsilateral on-directions and contain long-lead burst neurons. In a quantitative analysis the firing patterns of long-lead burst neurons are compared to those of medium-lead burst neurons, which form the predominant output of the saccadic pulse generator to the motoneurons. The firing patterns of temporally coded long-lead bursters are similar to those of medium-lead bursters, except for earlier on-latencies, larger statistical fluctuations, and specializations for small or large saccades in oblique directions. The spatially coded burst neurons form a motor map of saccadic vectors. The diameter of their movement field is often about the size of the saccade vector, and they encode saccadic onset and duration. These results are consistent with a model for visual saccades in eye displacement coordinates, where the spatio-temporal recording of horizontal eye movements is effected by long-lead burst neurons in the PPRF.
TL;DR: This is the second of two accounts reporting on the occurrence and systematics of freshwater species of the colourless chrysophycean genus Paraphysomonas in the Cambridge area, using electron microscopy of whole mounts of both cells and scales and sections of scales.
Abstract: This is the second of two accounts reporting on the occurrence and systematics of freshwater species of the colourless chrysophycean genus Paraphysomonas in the Cambridge area, using electron microscopy of whole mounts of both cells and scales and sections of scales. Twenty species are included here, eleven of which are new: P. cancellala, P. canistrum, P. homolepis, P. ignivoma, P. limbata, P. morchella, P. runcinifera, P. stelligera, P. stephanolepis, P. subquadrangularis and P. undulata. Five new subspecies are also established: P. circumvallata ssp. mediogranulata, P. poteriophora ssp. manubriata, P. punctata ssp. atrema, ssp. microlepis and ssp. simplicior. P. diademifera (Takahashi) comb. nov. [=Lepidochromonas diademifera (Takahashi) Kristiansen] has been included in Paraphysomonas since it has been found to be colourless and not pigmented as originally described and also to possess scales of a similar structure to those in other species of Paraphysomonas. One previously described species, P. inconspicua Takahashi, is here considered as a synonym of P. butcheri Pennick & Clarke. P. vacuolata Thomsen is removed from Paraphysomonas since it has been found to possess a chloroplast and will be included in a new genus in the third paper of this series. The 37 presently known species of Paraphysomonas have been arranged in 11 different groups according to similarities in scale structure. Consideration of the possible evolution of scale structure in Paraphysomonas and the possible interrelationships within the genus led to the conclusion that all species should be included in a single genus.
TL;DR: RNA extracted from the 12S "termination" factor includes an RNA species comigrating with the 60 nucleotide RNA from poly (A)- RNA, which is suggested to be present in relatively low abundance in embryos of both Psammechinus and Paracentrotus.
TL;DR: In this article, the extent of contamination of microcrystalline silicon samples by oxygen unless special precautions are taken as regards the sample preparation and/or handling is determined by measured values of the electrical conductivity, sigma, and electron spin density (g=2.0057).
Abstract: For pt.III see ibid., vol.16, p.2005 (1983). Measured values of the electrical conductivity, sigma , and electron spin density (g=2.0057) of microcrystalline silicon can be essentially determined by the extent of the contamination of the samples by oxygen unless special precautions are taken as regards the sample preparation and/or handling. For samples deposited at a floating potential, two kinds of oxygen incorporation are identified: irreversible formation of Si-O bonds on the grain boundaries (and on the sample surface) and a reversible absorption which is probably associated with a nondissociative O2delta - (ads) state. The latter results in a decrease of sigma RT by up to five orders of magnitude, an increase of the activation energy, epsilon a, and of the preexponential factor, sigma 0, as well as in an increase of the electron spin density. A reversible desorption of oxygen leads to an increase of sigma RT up to not less than about 10-2 Omega -1 cm-1 and a decrease of the EPR signal below the detection limit of less than 1016 cm-3. In order to avoid such effects a negative bias has to be applied to the substrate during deposition. Samples of undoped mu c-Si deposited in this way show neither the incorporation of oxygen into the bulk nor significant changes in the dark conductivity even after long-term exposure to air.
TL;DR: It is indicated that genetically defective in vivo metabolism of debrisoquine is caused by a deficiency of a monooxygenase reaction in liver microsomes, and direct measurement of the debrisoquines oxidation deficiency may allow the identification of heterozygous carriers of the defect.
TL;DR: The rat may be a suitable animal model in which to study the pathways underlying visual-vestibular interaction and saccadic mechanisms in the flocculus, and morphological evidence is provided that the midline and paramedian pontine tegmentum, identified in the cat and monkey as containing saccade-related neurons, send large numbers of projections to the rat Flocculus.
Abstract: The horseradish peroxidase (HRP) retrograde transport method was used to identify brainstem afferents to the cerebellar flocculus in the pigmented rat. Injections of the enzyme were made through recording microelectrodes, making it possible to localize the injection site by physiological criteria. Clearly, the largest number of afferents arise from the bilateral vestibular and perihypoglossal nuclei and from the contralateral dorsal cap (of Kooy) of the inferior olive. Additionally, a substantial number arise bilaterally from: (1) the nucleus reticularis tegmenti pontis (NRTP); (2) several of the cranial motor nuclei including the abducens, retrofacial and facial nuclei and the nucleus ambiguus; (3) the rostral part of the lateral reticular nucleus (subtrigeminal nucleus); (4) the raphe pontis and raphe magnus and (5) neurons intercalated among the medial longitudinal fasciculus (MLF) just rostral to the hypoglossal nucleus and another group rostral to the abducens nucleus. The basilar pontine nuclei contained a large number of lightly labeled neurons in all flocculus injections which were discretely located within the dorsolateral, lateral and medial divisions. These areas were labeled bilaterally but with a slight contralateral preponderance. Injection into the flocculus, but involving the adjacent ventral paraflocculus, produced a heavier labeling of pontine neurons with a slightly different distribution. Therefore, we tentatively conclude that the flocculus receives input from these pontine visual centers (dorsolateral, lateral and medial nuclei), perhaps through collateral projections from neurons projecting to the paraflocculus. The present study demonstrates strong similarities between the rat and other species studied (e.g., rabbit, cat, monkey) in terms of the brainstem nuclei projecting to the flocculus. Most noticeable in quantitative terms are the pathways known to mediate vestibular (vestibular and perihypoglossal nuclei) and visual (optokinetic) information (e.g., NRTP). Additionally, we can provide morphological evidence that the midline and paramedian pontine tegmentum, identified in the cat and monkey as containing saccade-related neurons, send large numbers of projections to the rat flocculus. Given these similarities, the rat may be a suitable animal model in which to study the pathways underlying visual-vestibular interaction and saccadic mechanisms in the flocculus.
TL;DR: It is suggested that in the first branchial arch muscles this is probably not directly comparable to the situation in the typical limb muscle, and therefore their common origin with the jaw-closers cannot be responsible for the occurrence of IIM fibres in tensor veli palatini and tensor tympani in some species.
Abstract: A combination of standard histochemical techniques and immunohistochemical staining using myosin type-specific antisera was used to determine the fibre-type composition of the muscles of first branchial arch origin (that is, masseter, temporalis, pterygoideus medialis and lateralis, tensor veli palatini, tensor tympani, anterior digastricus and mylohyoideus) in a wide range of the Carnivora and the Primates.
TL;DR: With the use of thin slices and coronal cuts both the angioma and its pattern of venous drainage can be indentified on CT in a high proportion of cases and with dynamic CT the specificity of CT in diagnosing cerebral venousAngioma may further increase.
Abstract: The angiographic and CT findings in seven cases of cerebral venous angioma are presented and analyzed. Two cases were also examined with dynamic CT. The radiological literature on the subject is reviewed and a new classification of cerebral venous angioma based on its pattern of drainage is proposed. It is concluded that with the use of thin slices and coronal cuts both the angioma and its pattern of venous drainage can be indentified on CT in a high proportion of cases. In addition, with dynamic CT the specificity of CT in diagnosing cerebral venous angioma may further increase.