Showing papers by "University of California, San Diego published in 1984"
TL;DR: A purified protein derived from the twisted beta-pleated sheet fibrils in cerebrovascular amyloidosis associated with Alzheimer's disease has been isolated and Amino acid sequence analysis and a computer search reveals this protein to have no homology with any protein sequenced thus far.
4,795 citations
TL;DR: Preliminary studies in 11 patients suggest that extending the photoperiod with bright artificial light has an antidepressant effect and sleep recordings in nine depressed patients confirmed the presence of hypersomnia and showed increased sleep latency and reduced slow-wave (delta) sleep.
Abstract: Seasonal affective disorder (SAD) is a syndrome characterized by recurrent depressions that occur annually at the same time each year. We describe 29 patients with SAD; most of them had a bipolar affective disorder, especially bipolar II, and their depressions were generally characterized by hypersomnia, overeating, and carbohydrate craving and seemed to respond to changes in climate and latitude. Sleep recordings in nine depressed patients confirmed the presence of hypersomnia and showed increased sleep latency and reduced slow-wave (delta) sleep. Preliminary studies in 11 patients suggest that extending the photoperiod with bright artificial light has an antidepressant effect.
2,186 citations
TL;DR: The cerebrovascular amyloid protein from a case of adult Down's syndrome was isolated and purified and Amino acid sequence analysis showed it to be homologous to that of the beta protein of Alzheimer's disease.
1,657 citations
TL;DR: Of 10 distinct cloned DNA copies of mRNAs expressed in T lymphocytes but not in B lymphocytes and associated with membrane-bound polysomes, one hybridizes to a region of the genome that has rearranged in a T- cell lymphoma and several T-cell hybridomas, suggesting that it encodes one chain of the elusive antigen receptor on the surface of T lymphocyte.
Abstract: Of 10 distinct cloned DNA copies of mRNAs expressed in T lymphocytes but not in B lymphocytes and associated with membrane-bound polysomes, one hybridizes to a region of the genome that has rearranged in a T-cell lymphoma and several T-cell hybridomas. These characteristics suggest that it encodes one chain of the elusive antigen receptor on the surface of T lymphocytes.
1,218 citations
TL;DR: In this article, the mineral solubility model of Harvie and Weare (1980) is extended to the eight component system, Na-K-Mg-Ca-H-Cl-SO4-OH-HCO3-CO3 -CO2-H2O at 25°C to high concentrations.
1,175 citations
TL;DR: In this paper, it is shown that the best method is to add a constant term and not to constrain the weights to add to unity, and that the optimum method proposed here is superior to the common practice of letting the weights add up to one.
Abstract: It is well known that a linear combination of forecasts can outperform individual forecasts. The common practice, however, is to obtain a weighted average of forecasts, with the weights adding up to unity. This paper considers three alternative approaches to obtaining linear combinations. It is shown that the best method is to add a constant term and not to constrain the weights to add to unity. These methods are tested with data on forecasts of quarterly hog prices, both within and out of sample. It is demonstrated that the optimum method proposed here is superior to the common practice of letting the weights add up to one.
1,088 citations
TL;DR: The maturation of ovarian follicles and their transformation into corpora lutea is regulated by a specific set of hormones and has been a major research area for ovarian physiologists for several hundred years.
Abstract: 1. Cell Culture Approach to the Study of Granulosa Cells In 1672, Regnier de Graaf first described the differentiation of ovarian follicles into the corpus luteum. He stated that “age and coitus cause very great changes in eggs (follicles). In young animals, they are very small and in more developed ones they are larger. After coitus, they (the follicles) so alter as to resemble the globules (the corpora lutea) …, being one or more according as the animal will produce one or more fetuses.” (1) Follicles as the functional unit: Ovarian follicles have since been shown to be the basic functional unit of the ovary and consist of an outer layer of theca interna cells which encircle inner layers of granulosa cells. Granulosa cells, in turn, surround the innermost oocyte-cumulus cell complex. The maturation of ovarian follicles and their transformation into corpora lutea is regulated by a specific set of hormones and has been a major research area for ovarian physiologists for several hundred years.
997 citations
TL;DR: A data structure for representing a set of n items from a universe of m items, which uses space n+o(n) and accommodates membership queries in constant time and is easy to implement.
Abstract: A data structure for representing a set of n items from a umverse of m items, which uses space n + o(n) and accommodates membership queries m constant time is described. Both the data structure and the query algorithm are easy to ~mplement.
943 citations
TL;DR: It is shown that food sharing by regurgitation of blood among wild vampire bats (Desmodus rotundus) depends equally and independently on degree of relatedness and an index of opportunity for recipro cation.
Abstract: Behavioural reciprocity can be evolutionarily stable1–3. Initial increase in frequency depends, however, on reciprocal altruists interacting predominantly with other reciprocal altruists either by associating within kin groups or by having sufficient memory to recognize and not aid nonreciprocators. Theory thus suggests that reciprocity should evolve more easily among animals which live in kin groups. Data are available separating reciprocity from nepotism only for unrelated nonhuman animals4. Here, I show that food sharing by regurgitation of blood among wild vampire bats (Desmodus rotundus) depends equally and independently on degree of relatedness and an index of opportunity for recipro cation. That reciprocity operates within groups containing both kin and nonkin is supported further with data on the availability of blood-sharing occasions, estimates of the economics of shar ing blood, and experiments which show that unrelated bats will reciprocally exchange blood in captivity.
871 citations
TL;DR: In this article, the authors compared different memory tests for words that were studied under either semantic or non-semantic processing conditions and found that free recall, cued recall, and word recognition showed substantially better performance under semantic processing conditions, while the rate of decrement in performance over time was the same for the completion and recognition tests.
749 citations
TL;DR: At Atomic-level details are now in hand for many of the interactions that hold fibrin units together, although some aspects have yet to be resolved.
Abstract: Fibrinogen is a soluble plasma protein that is converted to polymeric fibrin in response to damage to the vascular system The clotting process is initiated when platelets aggregate at the wound site Their disruption releases biologically active amines and a proteolytic cascade follows which culminates in the conversion of fibrinogen to fibrin The fibrin polymer forms the matrix of the tangle of cellular and molecular substances called the blood clot Atomic-level details are now in hand for many of the interactions that hold fibrin units together, although some aspects have yet to be resolved Of necessity, fibrin clots need to be dismantled when they are no longer needed, an operation largely accomplished by the proteolytic enzyme plasmin Various regulatory phenomena are involved in maintaining the balance between intravascular fluidity and clots that prevent blood loss A variety of hereditary conditions, including mutant fibrinogens, can predispose individuals to either thrombosis or bleeding
Key concepts:
The underlying fabric of blood clots is a protein polymer called fibrin
Fibrin clots are formed in response to injuries to any part of the vascular system
The conversion of soluble fibrinogen molecules to insoluble fibrin depends on thrombin generated from prothrombin
Keywords:
fibrinogen;
fibrin;
clot stabilisation;
fibrinolysis;
blood clotting;
X-ray structures
TL;DR: Two factors are identified which may account for the ability of the enzyme to stabilize high-oxidation states of the heme iron during catalysis: 1) the proximal histidine forms a hydrogen bond with a buried aspartic acid side chain, Asp-235; and 2) the heME environment is more polar than in the cytochromes c or globins.
TL;DR: Comparison of the sequence of a cloned T cell-specific cDNA with those of cross-reacting cloned cDNAs isolated from a thymocyte library indicates the presence of variable, constant and joining regions remarkably similar in size and sequence to those encoding immunoglobulin proteins.
Abstract: Comparison of the sequence of a cloned T cell-specific cDNA with those of cross-reacting cloned cDNAs isolated from a thymocyte library indicates the presence of variable, constant and joining regions remarkably similar in size and sequence to those encoding immunoglobulin proteins. Together with the evidence for somatic gene rearrangements reported in the accompanying paper, this strongly suggests that the TM86 cDNA clone encodes one chain of the T-cell receptor for antigen.
TL;DR: These findings suggested that spatially focused attention involves a gating or modulation of evoked neural activity in the visual pathways, whereas color selection is manifested by an endogenous ERP complex.
Abstract: Event-related brain potentials (ERPs) were recorded from subjects as they attended to colored bars that were flashed in random order to the left or right of fixation. The task was to detect slightly smaller target bars having a specified color (red or blue) and location (left or right). The ERP elicited by stimuli at an attended location contained a sequence of phasic components (P122/N168/N264) that was highly distinct from the sequence associated with selection on the basis of color (N150-350/P199/P400-500). These findings suggested that spatially focused attention involves a gating or modulation of evoked neural activity in the visual pathways, whereas color selection is manifested by an endogenous ERP complex. When the stimulus locations were widely separated, the ERP signs of color selection were hierarchically dependent upon the prior selection for spatial location. In contrast, when the stimulus locations were adjacent to one another, the ERP signs of color selection predominated over those of location selection. These results are viewed as supporting “early selection” theories of attention that specify the rejection of irrelevant inputs prior to the completion of perceptual processing. The implications of ERP data for theories of multidimensional stimulus processing are considered.
Journal Article•
TL;DR: In this article, three anti-EGF receptor MoAbs were used in the present studies, and all three MoAbs inhibited A431 tumor growth in athymic mice, indicating that the antibody isotype and the site of binding on the EGF receptor are not determinants of antiproliferative activity in vivo.
Abstract: Monoclonal antibodies (MoAbs) were raised against epidermal growth factor (EGF) receptors on a human epidermoid carcinoma cell line, A431. Administration of anti-EGF receptor MoAbs inhibited tumor formation in athymic mice by A431 cells and by another epidermal carcinoma cell line, T222. When one of the same MoAbs was used in therapy against Li-7 (a human hepatoma) and HeLa cells (a cervical carcinoma), tumor growth was not affected. The number of EGF receptors on A431 cells was about 100-fold higher than on T222, Li-7, and HeLa cells, suggesting that the number of EGF receptors may not be an important determinant in suppressing tumor growth. Three anti-EGF receptor MoAbs were used in the present studies. MoAbs 528 (immunoglobulin G2a) and 225 (immunoglobulin G1) are capable of competing with EGF for receptor binding and inhibit proliferation of A431 cells in culture. The other MoAb, 455 (immunoglobulin G1), is incapable of blocking the binding of EGF to its receptors and has no effect on the proliferation of cultured A431 cells. All three MoAbs inhibited A431 tumor growth in athymic mice, indicating that the antibody isotype and the site of binding on the EGF receptor are not the determinants of antiproliferative activity in vivo. The observation that MoAb against the receptor for EGF is cytostatic rather than cytocidal in vitro against A431 cells, yet completely prevents tumor growth in vivo, suggests that some host animal responses also may be involved in the antitumor effect. MoAbs against growth factor receptors could provide useful immunotherapeutic agents.
TL;DR: The hormonal form of vitamin D3, 1,25-dihydroxyvitamin D3 [1,25(OH)2D3], at picomolar concentrations, inhibited the growth-promoting lymphokine interleukin-2, which is produced by human T lymphocytes activated in vitro by the mitogen phytohemagglutinin.
Abstract: The hormonal form of vitamin D3, 1,25-dihydroxyvitamin D3 [1,25(OH)2D3], at picomolar concentrations, inhibited the growth-promoting lymphokine interleukin-2, which is produced by human T lymphocytes activated in vitro by the mitogen phytohemagglutinin Other metabolites of vitamin D3 were less effective than 1,25(OH)2D3 in suppressing interleukin-2; their order of potency corresponded to their respective affinity for the 1,25(OH)2D3 receptor, suggesting that the effect on interleukin-2 was mediated by this specific receptor The proliferation of mitogen-activated lymphocytes was also inhibited by 1,25(OH)2D3 This effect of the hormone became more pronounced at later stages of the culture These findings demonstrate that 1,25(OH)2D3 is an immunoregulatory hormone
TL;DR: The observation that MoAb against the receptor for EGF is cytostatic rather than cytocidal in vitro against A431 cells, yet completely prevents tumor growth in vivo, suggests that some host animal responses also may be involved in the antitumor effect.
TL;DR: Purified CNTF represents the first purified neuronotrophic factor which addresses parasympathetic cholinergic neurons and supports the 24‐h survival of cultured neurons from certain chick and rodent sensory and sympathetic ganglia.
Abstract: Dissociated 8-day chick embryo ciliary ganglionic neurons will not survive for even 24 h in culture without the addition of specific supplements. One such supplement is a protein termed the ciliary neuronotrophic factor (CNTF) which is present at very high concentrations within intraocular tissues that contain the same muscle cells innervated by ciliary ganglionic neurons in vivo. We describe here the purification of chick eye CNTF by a 2 1/2-day procedure involving the processing of intraocular tissue extract sequentially through DE52 ion-exchange chromatography, membrane ultrafiltration-concentration, sucrose density gradient ultracentrifugation, and preparative sodium dodecyl sulfate-polyacrylamide gradient electrophoresis. An aqueous extract of the tissue from 300 eyes will yield about 10-20 micrograms of biologically active, electrophoretically pure CNTF with a specific activity of 7.5 X 10(6) trophic units/mg protein. Purified CNTF has an Mr of 20,400 daltons and an isoelectric point of about 5, as determined by analytical gel electrophoresis. In addition to supporting the survival of ciliary ganglion neurons, purified CNTF also supports the 24-h survival of cultured neurons from certain chick and rodent sensory and sympathetic ganglia. CNTF differs from mouse submaxillary nerve growth factor (NGF) in molecular weight, isoelectric point, inability to be inactivated by antibodies to NGF, ability to support the in vitro survival of the ciliary ganglion neurons, and inability to support that of 8-day chick embryo dorsal root ganglionic neurons. Thus, CNTF represents the first purified neuronotrophic factor which addresses parasympathetic cholinergic neurons.
TL;DR: Four mouse monoclonal antibodies specific for human epidermal growth factor (EGF) receptors have been prepared using EGF receptor protein from human A431 epidermoid carcinoma cells as immunogen and the effect of these antibodies on two known functions of the E GF receptor: EGF binding and tyrosine kinase is determined.
TL;DR: It is reported that changes in the synthesis of flavonoids and furanocoumarins are due to transient increases in the transcription rates of the respective genes, which indicates that gene activation has an important role in UV and disease resistance in higher plants.
Abstract: The synthesis of secondary metabolites in response to stress conditions has been implicated as a major defence response of higher plants1. Cell suspension cultures of parsley (Petroselinum hortense) have been studied extensively as a model system and shown to respond to UV irradiation and treatment with fungal elicitor by the synthesis of flavonoids and furanocoumarins, respectively2,3. The induced synthesis of these compounds might afford the plant protection against the respective environmental hazards, because flavonoids strongly absorb UV light and furanocoumarins possess fungitoxic properties4. The production of each class of compound is preceded by the induction of groups of coordinately regulated enzymes2,5–8, based on rapid changes in amounts and activities of the corresponding messenger RNAs9,10. We now report that these changes are due to transient increases in the transcription rates of the respective genes, which indicates that gene activation has an important role in UV and disease resistance in higher plants.
TL;DR: The authors showed that participants in a test of sentence interpretation by German-, Italian-, and English-speaking adults showed that they relied overwhelming on word order, using a first-noun strategy in NVN and a second-neighbor strategy in VNN and NNV sentences.
TL;DR: In this article, modal analyses of 273 different peridotites representing 43 dredge stations in the Atlantic, Caribbean, and Indian Oceans define three separate melting trends, and demonstrate that they are the probable residues of variable degrees of mantle melting.
TL;DR: The finding suggests that N-myc gene may have a primary role in the turaorigenesis of retinoblastoma, and amplified N- myc gene is amplified 10–200-fold in two primary retinOBlastomas and a retin Oblastoma cell line Y79, suggesting this tumour is caused by two mutational events.
Abstract: Retinoblastoma, the most common intraocular tumour of childhood, probably arises from embryonal cells and occurs in hereditary and non-hereditary forms. Recent evidence suggests that this retinoblastoma (Rb) susceptibility gene located at chromosome 13q14 is actually recessive. Knudson has proposed that the tumour is caused by two mutational events. This idea was extended by Comings, who suggested that dominantly inherited tumours may result from loss or inactivation of both alleles of regulatory or suppressor genes that, when active, prevent the expression of a structural transforming gene(s) (possibly an oncogene) normally active only during embryogenesis. Despite circumstantial evidence for this hypothesis, no activated oncogene has been identified. We now report that (1) the N-myc gene is amplified 10-200-fold in two primary retinoblastomas and a retinoblastoma cell line Y79 and (2) expression of N-myc gene is highly elevated in most of the retinoblastomas examined. This finding suggests that N-myc gene may have a primary role in the tumorigenesis of retinoblastoma.
TL;DR: In this article, the authors propose an equation variationnelle for les deplacements and certain contraintes in vue d'une application aux plaques elastiques stratifiees isotropes and anisotropes.
Abstract: Formulation d'une equation variationnelle pour les deplacements et certaines contraintes en vue d'une application aux plaques elastiques stratifiees isotropes et anisotropes
TL;DR: Interactions between the lectins and glycoconjugates appear to play a role in shaping extracellular environments, as in mucin or slime.
Abstract: Soluble lectins of cellular slime molds and vertebrates are present at extracellular sites in the developing or adult tissues that make them. Some lectins are concentrated around cell groups, as in extracellular matrix or elastic fibers. Others are at the interface between cells and the external environment, as in mucin or slime. Specific glycoproteins, proteoglycans, or polysaccharides that bind these endogenous lectins may also be present at these sites. Interactions between the lectins and glycoconjugates appear to play a role in shaping extracellular environments.
TL;DR: In this paper, the authors collected sediment samples at 107 locations along the continental margin of northwest Africa and performed correlation coefficient-based cluster analyses to decipher the community structure for this margin.
TL;DR: There appear to be three cytoplasmic polyadenylated RNA products of EGF receptor gene expression in A431 cells, one of which contains only 5' (EGF binding domain) sequences and is postulated to encode the secreted EGF receptors-related protein.
Abstract: In order to further define the mechanisms by which polypeptide growth factors regulate gene transcription and cellular growth, expression cloning techniques were used to select human epidermal growth factor (EGF) receptor complementary DNA clones. The EGF 3' coding domain shows striking homology to the transforming gene product of avian erythroblastosis virus (v-erbB). Over-expression of EGF receptors in A431 cell lines correlates with increased EGF receptor mRNA levels and amplification (up to 110 times) of the apparently singular EGF receptor gene. There appear to be three cytoplasmic polyadenylated RNA products of EGF receptor gene expression in A431 cells, one of which contains only 5' (EGF binding domain) sequences and is postulated to encode the secreted EGF receptor-related protein.
TL;DR: The D. melanogaster DNA segment in the recombinant phage lambda Dm2L1 contains at least eight copies of a tandemly repeated 1250-base pair sequence (henceforth called the 2L1 sequence), which is present on both the X and Y chromosomes.
Abstract: The D. melanogaster DNA segment in the recombinant phage λDm2L1 contains at least eight copies of a tandemly repeated 1250-base pair (bp) sequence (henceforth called the 2L1 sequence). Testes from XO D. melanogaster males contain an abundant 800-base RNA species that is homologous to a 520-bp region of the 2L1 sequence. Blotting experiments show that the 2L1 sequence is repeated in the D. melanogaster genome and is present on both the X and Y chromosomes. With the use of X-Y translocations, the 2L1 sequence has been mapped to a region between kl-1 and kl-2 on the long arm of the Y chromosome. In Oregon-R wild type there are an estimated 200 copies of the 2L1 sequence on the X chromosome and probably at least 80 copies on the Y chromosome. In some other strains the repetition frequency on the Y chromosome is about the same, but the copy number on the X chromosome is much reduced. On the basis of the five strains investigated, there is a correlation between copy number of the 2L1 sequence on the X chromosome and the presence of a particular allele of the Stellate locus (Ste; 1-45.7). It seems that low copy number corresponds to Ste + and high copy number corresponds to Ste. The Ste locus determines whether single or star-shaped crystals are observed in the spermatocytes of XO males. Studies using D. simulans and D. mauritiana DNA show that the 2L1 sequence is homologous to restriction fragments in male DNA but not female DNA, indicating that this sequence is present only on the Y chromosome in these two species. In DNA derived from D. erecta, D. teissieri and D. yakuba, there is very little, if any, hybridization with the 2L1 sequence probe.
TL;DR: In this paper, a monopoly seller of a durable good holds periodic sales as a means of price discrimination, and a new cohort of consumers enters the market in each period, interested in purchasing the good either immediately or after a delay.
Abstract: In the model of this paper a monopoly seller of a durable good holds periodic sales as a means of price discrimination. A new cohort of consumers enters the market in each period, interested in purchasing the good either immediately or after a delay. Within each cohort, consumers vary in their tastes for the good. Under broad conditions, the seller will vary the price over time. In most periods, he will charge a price just low enough to sell immediately to consumers with a high willingness to pay. Periodically, however, he will drop the price far enough to sell to an accumulated group of consumers with a low willingness to pay.
TL;DR: Complex principal component (CPC) analysis is shown to be a useful method for identifying traveling and standing waves in geophysical data sets as discussed by the authors, and combines of simple progressive and standing oscillations are used to examine the properties of this technique.
Abstract: Complex principal component (CPC) analysis is shown to be a useful method for identifying traveling and standing waves in geophysical data sets. Combinations of simple progressive and standing oscillations are used to examine the properties of this technique. These examples illustrate that although CPC analysis allows for the identification of traveling waves, many of the drawbacks associated with conventional principal component analysis remain, and sometimes become worse; e.g. the interpretation of CPC solutions is more difficult since both amplitude and phase relationships must be considered. A method for linearly transforming complex principal components was devised in order to identify regional relationships within large geophysical data sets. The errors in CPC analysis resulting from limited sample sizes are discussed.