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PubMed2000

Comparative cognition in the 1930s.

According to the received view of the history of psychology, behaviorism so dominated psychology prior to the 1960s that there was little research in animal cognition. A review of the research on animal cognition during the 1930s reveals a rich literature dealing with such topics as insight, reasoning, tool use, delay problems, oddity learning, abstraction, spatial cognition, and problem solving, among others. Material on "higher processes" or a related topic was prominent in the textbooks of the period. Tracing academic lineages reveals such teachers as Harvey Carr, Robert M. Yerkes, and Edward C. Tolman as sources of this interest. The alleged hegemony of strict behavioristic psychology, interpreted as excluding research on animal cognition, requires revision. Some possible reasons for this neglect are suggested.

Animals↗
PubMed2006

The evolutionary role of the pharmacy and therapeutics committee in technology assessment.

The origins of the Pharmacy and Therapeutics (P&T) Committee is intertwined with the evolution of the modern practice of pharmacy. Although the P&T Committee has been uniquely developed to help make coverage decisions, this implies that its technology assessment function, particularly with regard to medicines, has paved the way to more cost-effective and evidence-based practice. This article, which briefly traces the lineage of the first known "formulary" employed during the Revolutionary War to today's P&T Committee, argues that its true function--technology assessment--serves as the basis for coverage decisions throughout health systems.

Pharmacy and Therapeutics Committee↗
PubMed1984

Membrane antigen in small cell carcinoma of the lung defined by monoclonal antibody SM1.

Mouse myeloma cells were fused with spleen cells from BALB/c mice immunized with a cell line derived from human small cell carcinoma (SCC) of the lung. The cloned hybridoma SM1 produced antibody that was reactive with the surface membrane of SCC cell lines and SCC tumors but not with the membrane of several non-SCC cell lines and tumors. SM1 ascites fluid was used to screen for reactivity of the antibody with other human cancer cell lines, tumor tissues, and normal tissues. SM1 antibody was found to be unreactive with neuroblastoma, adrenal carcinoma, melanoma, and bronchial carcinoid. Reactivity was detected with some breast carcinoma cell lines but not with breast cancer tissue specimens. In the same individual, the antibody was reactive with SCC lung tumor and SCC metastatic to the liver but not with normal tissues, including bronchus, lung parenchyma, liver, kidney, and brain. Human erythrocytes and marrow cells were also unreactive. Since SM1 detects an antigen that is present in greatest amounts on the surface membrane of SCC of the lung, this antibody may be useful in tracing the lineage patterns of human lung cancers.

Animals↗
PubMedDate not supplied

Isolation and cultivation of Lyme disease spirochetes.

The successful isolation and cultivation of Lyme disease spirochetes traces its lineage to early attempts at cultivating relapsing fever borreliae. Observations on the growth of Lyme disease spirochetes under different in vitro conditions may yield important clues to both the metabolic characteristics of these newly discovered organisms and the pathogenesis of Lyme disease.

Bacteriological Techniques↗
PubMed1994

The grasshopper median neuroblast is a multipotent progenitor cell that generates glia and neurons in distinct temporal phases.

The midline of the insect CNS provides a good system for studying the control of neuronal and glial cell fates, because it contains a small number of distinct cell types that arise from a unique set of precursors. In this report we analyze the development of the CNS midline in the grasshopper embryo, focusing on the median neuroblast (MNB) cluster, which contains the majority of midline neurons. We have directly traced cell lineage in the MNB cluster by injecting the MNB with tracer dyes and following the development of its progeny in whole embryo cultures. As least three types of neuronal progeny are labeled with tracer dye in these experiments. In addition, we find that all of the midline glia are also derived from the MNB. Thus, this neuroblast is actually a multipotent progenitor cell. We also examined the temporal and spatial patterns of midline development by staining embryos with antibodies to neuronal and glial markers and to the protein product of the engrailed gene, which is transiently expressed by all MNB progeny. Our data show that neuronal and glial progeny are generated from the MNB in distinct temporal phases. A change in the orientation of the MNB's mitotic spindle correlates with the transition between two of the phases of progeny production.

Animals↗
PubMedDate not supplied

[The prevalence of disseminated sclerosis in the southern region of Ukraine].

Some aspects were studied of the occurrence of disseminated sclerosis (DS) in the south of Ukraine (Odessa and Nikolaev Provinces) with special reference to geoclimatic, ecological and ethnic factors over the period 1992-1993, DS incidence was noted to be on the increase in the region, which fact permits classifying the South territories of Ukraine as a zone with moderate DS prevalence. Data are submitted on nonuniformity of distribution of frequency of DS cases on the territory in question. Lineage was traced to the climatic-and-geographic factors of the region, locality one lives in as well as to sex and race.

Adolescent↗
PubMed2004

Insights into the western Bantu dispersal: mtDNA lineage analysis in Angola.

Africa is the homeland of humankind and it is known to harbour the highest levels of human genetic diversity. However, many continental regions, especially in the sub-Saharan side, still remain largely uncharacterized (i.e. southwest and central Africa). Here, we examine the mitochondrial DNA (mtDNA) variation in a sample from Angola. The two mtDNA hypervariable segments as well as the 9-bp tandem repeat on the COII/tRNA(lys) intergenic region have allowed us to allocate mtDNAs to common African haplogroups. Angola lies in the southern end of the putative western branch of the Bantu expansion, where it met the local Khoisan populations. Angolan mtDNA lineages show basically a Bantu substrate with no traces of Khoisan lineages. Roughly, more than half of the southwestern mtDNA pool can be assigned to west Africa, approximately 25% to central Africa and a significant 16% to east Africa, which points to the western gene pool having contributed most to the mtDNA lineages in Angola. We have also detected signals of extensive gene flow from southeast Africa. Our results suggest that eastern and western Bantu expansion routes were not independent from each other, and were connected south of the rainforest and along the southern African savannah. In agreement with historical documentation, the analysis also showed that the Angola mtDNA genetic pool shows affinities with the African lineages from Brazil, the main American destination of the slaves from Angola, although not all lineages in Brazil can be accounted for by the Angolan mtDNA pool.

Angola↗
PubMed2004

A stop-EGFP transgenic mouse to detect clonal cell lineages generated by mutation.

The investigation of cell lineages and clonal organization in tissues is facilitated by techniques that allow labelling of clonal cell lineages. Here, we describe a novel transgenic mouse that allows clonal cell lineages to be traced in virtually any tissue. A green fluorescent cell lineage is generated by a random mutation at an enhanced green fluorescent protein gene that carries a premature stop codon, ensuring clonality. The transgenic system allows efficient detection of mutations and stem-cell fate mapping in the epidermis using live mice, as well as in the kidney and liver post-mortem. Cell lineages that descended from single epidermal stem cells were found to be capable of generating three adjacent corneocytes using the system, providing evidence for horizontal migration of epidermal cells between epidermal proliferative units (EPUs), in contrast to the classical EPU model. The transgenic mouse system is expected to provide a novel tool for stem-cell lineage studies.

Animals↗
PubMed2003

The horseradish peroxidase technique for cell lineage studies.

The identification of cell lineage for a given cell type of a particular tissue is an important step in understanding how this process contributes to histogenesis. The importance in understanding cell lineage has relevance for both theoretical and practical reasons. For example, delineating and identifying histogenic principals is required to advance stem cell research and tissue regeneration. To document cell lineage in a given experimental preparation, a number of techniques have been developed. This typically requires the injection of a tracer compound into a founder cell. As this cell produces progeny, the tracer is passed on to the daughter cells. By detecting the tracer in the progeny or daughter cells the investigator can determine which cells originated from the cell that was originally injected with the tracer. By using such an approach it is possible to trace the developmental path from the first cells of the embryo to the specialized cells making the tissue of the adult. A number of tracer compounds have been used with good results in lineage tracing. One of these tracer compounds is horseradish peroxidase (HRP). Several variations of the technique are available depending on what species are studied or what histological requirements are made by the study. A basic technique that can be adapted to individual needs is presented. Included in this protocol on lineage tracing are the procedures for injection, fixation, and the microscope evaluation of labelled cells in the Helobdella triseralis embryo. A brief discussion of the technique will note its advantages and disadvantages. Examples of labelled cell preparations are given to illustrate the technique.

Animals↗
PubMed2006

African-American mitochondrial DNAs often match mtDNAs found in multiple African ethnic groups.

BACKGROUND: Mitochondrial DNA (mtDNA) haplotypes have become popular tools for tracing maternal ancestry, and several companies offer this service to the general public. Numerous studies have demonstrated that human mtDNA haplotypes can be used with confidence to identify the continent where the haplotype originated. Ideally, mtDNA haplotypes could also be used to identify a particular country or ethnic group from which the maternal ancestor emanated. However, the geographic distribution of mtDNA haplotypes is greatly influenced by the movement of both individuals and population groups. Consequently, common mtDNA haplotypes are shared among multiple ethnic groups. We have studied the distribution of mtDNA haplotypes among West African ethnic groups to determine how often mtDNA haplotypes can be used to reconnect Americans of African descent to a country or ethnic group of a maternal African ancestor. The nucleotide sequence of the mtDNA hypervariable segment I (HVS-I) usually provides sufficient information to assign a particular mtDNA to the proper haplogroup, and it contains most of the variation that is available to distinguish a particular mtDNA haplotype from closely related haplotypes. In this study, samples of general African-American and specific Gullah/Geechee HVS-I haplotypes were compared with two databases of HVS-I haplotypes from sub-Saharan Africa, and the incidence of perfect matches recorded for each sample. RESULTS: When two independent African-American samples were analyzed, more than half of the sampled HVS-I mtDNA haplotypes exactly matched common haplotypes that were shared among multiple African ethnic groups. Another 40% did not match any sequence in the database, and fewer than 10% were an exact match to a sequence from a single African ethnic group. Differences in the regional distribution of haplotypes were observed in the African database, and the African-American haplotypes were more likely to match haplotypes found in ethnic groups from West or West Central Africa than those found in eastern or southern Africa. Fewer than 14% of the African-American mtDNA sequences matched sequences from only West Africa or only West Central Africa. CONCLUSION: Our database of sub-Saharan mtDNA sequences includes the most common haplotypes that are shared among ethnic groups from multiple regions of Africa. These common haplotypes have been found in half of all sub-Saharan Africans. More than 60% of the remaining haplotypes differ from the common haplotypes at a single nucleotide position in the HVS-I region, and they are likely to occur at varying frequencies within sub-Saharan Africa. However, the finding that 40% of the African-American mtDNAs analyzed had no match in the database indicates that only a small fraction of the total number of African haplotypes has been identified. In addition, the finding that fewer than 10% of African-American mtDNAs matched mtDNA sequences from a single African region suggests that few African Americans might be able to trace their mtDNA lineages to a particular region of Africa, and even fewer will be able to trace their mtDNA to a single ethnic group. However, no firm conclusions should be made until a much larger database is available. It is clear, however, that when identical mtDNA haplotypes are shared among many ethnic groups from different parts of Africa, it is impossible to determine which single ethnic group was the source of a particular maternal ancestor based on the mtDNA sequence.

Africa South of the Sahara↗
PubMed2004

Magnifying stem cell lineages: the stop-EGFP mouse.

Cell fate mapping techniques which can label clonal cell lineages are of importance because they allow one to investigate the distribution and types of daughter cells arising from single precursor cells. Thus, the potential of precursor cells to generate various types of descendent cells can be studied at the single-cell level. The stop-EGFP transgenic mouse carries a premature stop codon-containing enhanced green fluorescent protein (EGFP) gene as a target gene for mutations. A cell having undergone a mutation at the premature stop codon and its descendant cell lineage will express EGFP, thus a clonal cell lineage can be traced in vivo using a fluorescent microscope. Using the stop-EGFP mouse, stem cell clonal lineages in the mouse dorsal epidermis can be investigated in vivo and repeated analyses of the same cell lineages can be performed over time. In vivo imaging studies possible with the stop-EGFP mouse provide new insights into the structure of epidermal proliferative units (EPUs). The stop-EGFP system provides a novel tool for investigating clonal cell lineages in developmental studies as well as in stem cell biology.

Animals↗
PubMed1999

Structure and developmental expression of the ascidian TRP gene: insights into the evolution of pigment cell-specific gene expression.

The tyrosinase family in vertebrates consists of three related melanogenic enzymes: tyrosinase, tyrosinase-related protein-1 (TRP-1), and TRP-2. These proteins control melanin production in pigment cells and play a crucial role in determining vertebrate coloration. We have isolated a gene from the ascidian Halocynthia roretzi which encodes a tyrosinase-related protein (HrTRP) with 45-49% identity with vertebrate TRP-1 and TRP-2. The expression of the HrTRP gene in pigment lineage a8.25 cells starts at the early-mid gastrula stage, which coincides with the stage when these cells are determined as pigment precursor cells; therefore, it provides the earliest pigment lineage-specific marker, which enables us to trace the complete cell lineage leading to two pigment cells in the larval brain. In addition, the expression pattern of the HrTRP gene appears to share similar characteristics with the mouse TRP-2 gene although structurally the HrTRP gene is more closely related to mammalian TRP-1 genes. Based on these observations and on results from molecular phylogenetic and hybridization analyses, we suggest that triplication of the tyrosinase family occurred during the early radiation of chordates. Initially, duplication of an ancestral tyrosinase gene produced a single TRP gene before the urochordate and cephalochordate-vertebrate divergence, and a subsequent duplication of the ancestral TRP gene in the vertebrate lineage gave rise to two TRP genes before the emergence of teleost fishes. Evolution of the melanin synthetic pathway and possible phylogenetic relationships among chordate pigment cells that accommodate the metabolic process are discussed. Dev Dyn 1999;215:225-237.

Amino Acid Sequence↗
PubMed2006

Exploration of the emergence of the Victoria lineage of influenza B virus.

The Victoria lineage represented by B/Victoria/2/87 is one of the two major distinctive haemagglutinin (HA) lineages of influenza B virus, and its recent re-emergence has aroused great concerns. However, it remains unknown when, where, and how this HA lineage emerged in the world. In this study, the HA1 domain of the HA gene of fourteen influenza B viruses isolated in China in 1972-1984 was sequenced. The sequences were phylogenetically analyzed with the HA1 sequences of 41 other important influenza B isolates. The results unveiled some earlier footprints of the Victoria lineage in China, and the epidemic history of the Victoria lineage could be traced back from the year 1985 to 1975. Moreover, phylogenetic analysis, the history of China, and the epidemiology of influenza B virus indicated that the Victoria lineage possibly emerged in China in the 1970s through gradual evolution from a minor lineage.

Amino Acid Sequence↗
PubMed1995

Man and the chimaera. Selective versus neutral oxytocin evolution.

The oxytocin/vasopressin superfamily encompasses vertebrate and invertebrate peptides and therefore the ancestral gene encoding the precursor protein antedates the divergence between the two groups, about 700 million years ago. The preserved nonapeptide pattern indicates that both the precursor structures and the processing enzymatic machinery were greatly conserved to ensure the building of a specific conformation. Substitutions, which may be neutral or selective, occurred in precise positions. Virtually all vertebrate species possess an oxytocin-like and a vasopressin-like peptide so that two evolutionary lineages can be traced. Because a single peptide, vasotocin ([Ile3]-vasopressin or [Arg8]-oxytocin) has been found in the most primitive Cyclostomata, a primordial gene duplication and subsequent mutations are assumed to have given rise to the two lineages. They started with vasotocin and isotocin ([Ser4,Ile8]-oxytocin) in bony fishes and culminated with vasopressin and oxytocin in placental mammals. Mesotocin ([Ile3]-oxytocin), found in lungfishes, amphibians, reptiles, birds and marsupials, appears as an evolutionary intermediate. The change from isotocin ([Ser4,Ile8]-oxytocin) into mesotocin ([Ile8]-oxytocin), can be observed in African and Australian lungfishes, species making the transition from bony fishes to land vertebrates. On the other hand the replacement of mesotocin by oxytocin can be detected in marsupials, particularly in the North-American opossum and the Australian Northern bandicoot that have both mesotocin and oxytocin whereas placental mammals possess only oxytocin. The invariability of this peptide in placentals can be explained by receptor-fitting selective pressure. In contrast to bony vertebrates in which neurohypophysial hormones revealed a remarkable structural stability, cartilaginous fishes displayed an unique oxytocin-like hormone evolution with variability and duality. Aside from vasotocin, in the subclass Selachii, rays have glumitocin ([Gln8-oxytocin]) and sharks possess two peptides: aspargtocin ([Asn4-oxytocin]) and valitocin ([Val8-oxytocin]) for the spiny dogfish, asvatocin ([Asn4,Val8]-oxytocin) and phasvatocin ([Phe3,Asn4,Val8]-oxytocin) for the spotted dogfish. In the other subclass Holocephali, the chimaera (ratfish) has oxytocin, the typical hormone of placental mammals. Cartilaginous fishes used urea rather than salts for their osmoregulation and oxytocin-like hormones could have been relieved from osmoregulatory functions and able to accept many neutral variations.

Amino Acid Sequence↗
PubMed2001

Species traits and environmental constraints: entomological research and the history of ecological theory.

The role that entomology has played in the historical (1800s-1970s) development of ecological theories that match species traits with environmental constraints is reviewed along three lineages originating from the ideas of a minister (Malthus TR. 1798. An Essay on the Principle of Population. London: Johnson) and a chemist (Liebig J. 1840. Die Organische Chemie in ihrer Anwendung auf Agricultur und Physiologie. Braunschweig: Vieweg). Major developments in lineage 1 focus on habitat as a filter for species traits, succession, nonequilibrium and equilibrium conditions, and generalizations about the correlation of traits to environmental constraints. In lineage 2, we trace the evolution of the niche concept and focus on ecophysiological traits, biotic interactions, and environmental conditions. Finally, we describe the conceptual route from early demographic studies of human and animal populations to the r-K concept in lineage 3. In the 1970s, the entomologist Southwood merged these three lineages into the "habitat templet concept" (Southwood TRE. 1977. J. Anim. Ecol. 46:337-65), which has stimulated much subsequent research in entomology and general ecology. We conclude that insects have been a far more important resource for the development of ecological theory than previously acknowledged.

Animals↗
PubMed1996

Tracing the development of single memory-lineage B cells in a highly defined immune response.

To study the development of B lymphocyte memory, we identified and isolated splenic B cells expressing a highly defined antibody variable region that constitutes a reproducible and predominant component of the memory antibody response to p-azophenylarsonate (Ars). Isolation was achieved during the primary immune response by surface staining and flow cytometry using a specific anti-idiotypic antibody called E4, which recognizes this canonical V region, encoded by one set of V gene segments. The isolated E4+ cells displayed all of the phenotypic characteristics of germinal center centrocytes, including a low level of surface Ig, a lack of surface IgD, a high level of receptor for peanut agglutinin, and expression of mutated antibody V genes. E4+ B cells were first detected in the spleen 7-8 d after primary immunization, reached peak numbers from days 10-13, and waned by day 16. Surprisingly, at their peak, E4+ cells comprised only 40,000 of all splenocytes, and half of these failed to bind Ars. Using this number, we estimate the total number of Ars-specific memory-lineage cells in the spleen to be no more than 50,000 (0.1%) at any one time, and presumably far fewer that are committed to the memory pool. Chromosomal copies of rearranged V genes from single E4+ cells were amplified by nested PCR, and the amplified products were sequenced directly without cloning, using standardized conditions that disclose virtually no Taq polymerase errors. V gene sequence analyses of E4+ cells isolated from single mice confirmed their canonical nature and revealed that they were derived from few precursors. In the average mouse, the E4+ pool was derived from fewer than five canonical precursors. Somatic mutations were found within the V genes of almost all cell isolates. At day 13, a significant fraction of E4+ cells had mutations known to increase antibody affinity for Ars, suggesting they were products of at least one cycle of post-mutational antigen-driven selection. However, the lack of shared mutations by clonally related cells indicated that the selective expansion of mutant subclones typical of memory responses had not yet taken place. This was supported by the observation that half of the E4+ cells failed to bind Ars. Collectively, our results indicate that the memory compartment is a highly selected entity, even at relatively early stages of the primary immune response when somatic mutation and clonal selection are still in progress. If germinal centers are the source of memory B cells, our data suggest that B cell memory may be derived from only a small fraction of all germinal centers.

Amino Acid Sequence↗
PubMed1991

Molecular diversity of cytokeratins: significance for cell and tumor differentiation.

Normal and transformed epithelial cells are characterized by the expression of a distinct class of intermediate filaments (IFs), the cytokeratin (CK) filaments. Their constituents, the CKs, comprise a complex multigene family of related proteins which can be subdivided into two sequence types (I and II). In the various epithelial cell types (excluding trichocytes), 19 different CK polypeptides (CKs 1-19) have been distinguished until recently. An additional cytoskeletal polypeptide of Mr 46,000 has been detected, by gel electrophoresis and by immunocytochemistry, in certain types of epithelia including gastric foveolar epithelium, small and large intestinal epithelium, urothelium, and epidermal Merkel cells. On the basis of its biochemical properties and considerable sequence homologies with several type I CKs, this new cytoskeletal protein is suggested to be included in the catalogue of human CKs as CK 20. The various CK polypeptides, as detected by gel electrophoretic and/or immunocytochemical analysis, are expressed in different epithelia and carcinomas in various combinations in a differentiation-dependent manner. Moreover, co-expressions of CKs with other IF classes (vimentin, neurofilaments, glial filaments) are also characteristic of certain epithelial differentiation lineages. Both non-neoplastic epithelial alterations as well as malignant transformation may result in similar modifications of the IF expression profiles although there is a considerable tendency of conservativity. In several instances, a reduced degree of differentiation is paralleled by an increased complexity of the IF protein pattern. CK (and IF) typing can be successfully used in the tracing of developmental lineages as well as in the histological differential diagnosis of primary and metastatic carcinomas. Certain CK polypeptides (CKs 5, 6, 14, 16, 17) identify squamous cell carcinomas including poorly differentiated ones, while other CKs, including CK 20, are typical of primary and metastatic urothelium-derived carcinomas. Among simple-epithelial tumors, CK analysis is of potential diagnostic value in the distinction of mesotheliomas from adenocarcinomas, the discrimination of different carcinomas within the gastrointestinal tract, and the distinction of certain gastrointestinal carcinomas from other adenocarcinoma types including breast and lung carcinomas. Among the individual CKs, CKs 5, 7, 13, 14, 19, and 20 appear to be particularly useful for diagnostic purposes. An important task in the future will be the development of additional monospecific CK-antibodies, particularly such which work on routine paraffin sections.

Cell Differentiation↗
PubMed2005

Mosaic analysis with double markers in mice.

We describe a method termed MADM (mosaic analysis with double markers) in mice that allows simultaneous labeling and gene knockout in clones of somatic cells or isolated single cells in vivo. Two reciprocally chimeric genes, each containing the N terminus of one marker and the C terminus of the other marker interrupted by a loxP-containing intron, are knocked in at identical locations on homologous chromosomes. Functional expression of markers requires Cre-mediated interchromosomal recombination. MADM reveals that interchromosomal recombination can be induced efficiently in vivo in both mitotic and postmitotic cells in all tissues examined. It can be used to create conditional knockouts in small populations of labeled cells, to determine cell lineage, and to trace neuronal connections. To illustrate the utility of MADM, we show that cerebellar granule cell progenitors are fated at an early stage to produce granule cells with axonal projections limited to specific sublayers of the cerebellar cortex.

Animals↗