bluuebunny/crossref_metadata_2025 huggingface dataset:
BIOCHEMICAL and CLINICAL ASPECTS OF MEGATHROMBOCYTES
Authors: Karpatkin Simon
Published: December 2006

Human platelets have been separated into heavy and light populations by differential centrifugation in specific density media. The heavy‐platelet population has an average volume approximately 2–2.4‐fold that of the light‐platelet population. All eleven enzymes of the Embden‐Meyerhof pathway were examined in both platelet populations. Six of the eleven were found to have a twofold greater content/g wet weight in heavy platelets compared to light platelets. Three of these six: hexokinase, phosphofructokinase, and glyceraldehyde‐3‐P‐dehydroge‐nase were found to be rate‐limiting for glycolysis. The reductive capacity of heavy vs. light platelets was also examined. Heavy platelets contained 1.9‐fold greater GSH, 1.7‐fold greater DPNH, and 1.2‐fold greater TPNH than light platelets. Heavy platelets also contained 1.8‐fold less lipid peroxidation products than light platelets and were 2.4‐fold more resistant to lipid peroxidation catalysed by 0.1 mM FeCl3.

Kinetic studies in humans with Se75‐selenomethionine revealed that heavy‐large platelets were young platelets, recently released from the bone marrow, and suggested a transition of heavy‐large platelets to lighter‐smaller platelets.

Clinical studies in humans revealed the usefulness of the measurement of the percentage of large platelets (or megathrombocytes) in estimating platelet turnover. An excellent correlation was found between the percentage of megathrombocytes on EDTA peripheral smear (and as determined by volume with Coulter Counter) and the number of megakaryocytes in the bone marrow in all platelet disorders examined with low or normal platelet counts, r=0.70 P < 0.001, except in megaloblastic anemia. In megaloblastic anemia, an increase in the percentage of megathrombocytes was usually found, but in the absence of increased megakaryocyte number. Increased megathrombocyte number (% megathrombocytes X platelet count) could be used to predict compensated thrombocytolytic states: normal platelet counts in the presence of increased platelet turnover. This was detectable in 84 patients. Platelet survival studies with DFP32 were obtained in eight of these patients and found to be exponential and significantly shortened in all eight. Megathrombocyte number was also examined in various clinical disorders (with normal platelet counts) in which increased platelet turnover might be suspected. Significant elevations were noted in SLE (68%), rheumatic heart disease with severe valvular damage (63%), disseminated intravascular coagulation (60%), chronic autoimmune thrombocytopenic purpura “in remission” (55%), and diabetes mellitus with retinopathy (47%).
FACTORS AFFECTING HEMOSTATIC PLUG FORMATION IN AN EXTRACORPOREAL MODEL*
Authors: Didisheim Paul , Pavlovsky Miguel , Kobayashi Itsuro
Published: December 2006

A model is described for the study of factors affecting hemostasis. It consists of a Teflon extension of the carotid artery of rats. Holes of precise diameter are then produced in the extension with a micromanipulator and the aid of a microscope. The bleeding time of these holes is then recorded.

The principal advantage of this method is that it makes possible the production in the “blood vessel” of holes the diameters of which are known with a high degree of accuracy, under known conditions of intravascular pressure.

With holes below 75 μ in diameter, prolongation of the coagulation time with heparin did not affect the bleeding time. With increasing hole diameters, or with increasing intravascular pressure, coagulation time did affect the bleeding time. Bleeding time could be predictably modified by increasing or decreasing blood pressure. There is a striking interrelationship of these factors in influencing the bleeding time.

Intravenous pyridinolcarbamate (12 mg/kg) significantly prolonged the bleeding time for a 20‐minute period. At a lower dose (8 mg/kg), which was ineffective in prolonging the bleeding time, pyridinolcarbamate partially inhibited the shortening of the bleeding time that follows the administration of epinephrine.

Intravenous polyvinylpyrrolidone (PVP), 750 mg/kg, caused a sustained prolongation of the bleeding time, lasting more than three hours.
PLATELET MEMBRANE MUCOPOLYSACCHARIDES: SOME RELEVANT OBSERVATIONS*
Authors: O'Brien John R.
Published: December 2006

Biochemical analysis disorganizes the membrane before study; thus there are advantages in studying reactions of intact cells. Alcian blue (AB) causes aggregation of washed red cells–presumably because of membrane staining and a charge effect. Neuraminidase or the presence of plasma prevents this aggregation. AB added to platelets without plasma causes immediate aggregation; added to platelet‐rich plasma at low concentration, it potentiates ADP‐induced aggregation. A higher concentration stains the granules and causes release and delayed aggregation. Aspirin inhibits release induced by ADP but hardly influences that induced by AB. This suggests that aspirin inhibits an early stage of release, since adding AB shows that the later stages are still intact. During release, platelet factor 4, a glycoprotein, is liberated. Thereafter the platelet membrane stains with ruthenium red, but not before. Neuraminidase removes sialic acid. It prevents red cells but not platelets from aggregating with AB, and it exposes platelet factor 3 sites on platelets but not on red cells.

These findings are believed to relate to the organization of mucopolysaccharides and glycoproteins in the platelet membrane.
NATURE OF THE PLATELET DEFECT IN THE WISKOTT‐ALDRICH SYNDROME*
Authors: Baldini Mario G.
Published: December 2006

The thrombocytopenia in patients with the Wiskott‐Aldrich syndrome was found to be due to increased platelet destruction caused by an intracorpuscular cell defect. Multiple abnormalities of platelet structure, function, and metabolism were also observed. Platelet adhesiveness to collagen, and platelet aggregation with ADP, collagen, and epinephrine were reduced or absent in the affected patients and partially depressed also in the clinically normal female carrier. Of various biochemical alterations, the decrease in platelet glycogen and in hexokinase activity were most prominent. The latter defect was, however, not rate limiting. Although these platelets were capable of phagocytosis, the typical metabolic reaction to it, with increase in the citric acid cycle activity, did not occur. This reaction was severely depressed also when other aggregating stimuli such as ADP, collagen, and epinephrine were used. Thrombin, on the other hand, could produce both aggregation and stimulation of the citric acid cycle. It is concluded that platelets in the Wiskott‐Aldrich syndrome have a basic defect in energy metabolism. Although there is no intrinsic block in anaerobic and aerobic glycolysis, stimulation of the citric acid cycle does not occur with common aggregating (and degranulating) agents, most probably because a physiologic “regulator” of this metabolic pathway, the energy of which is indispensable for normal platelet aggregation, is lacking or is not made available. Thrombin can either liberate or substitute for such regulator.
IMMUNOTHERAPY OF CHRONIC MYELOCYTIC LEUKEMIA: EFFECTS OF DIFFERENT VACCINATION SCHEDULES*
Authors: Sokal Joseph E. , Aungst C. William , Snyderman Michael , Gomez German
Published: December 2006

In a clinical trial of immunotherapy in chronic myelocytic leukemia, 62 patients received repeated intradermal injections of BCG‐cultured cell mixtures, while 16 were vaccinated with BCG alone. The lymphoblastoid cell lines used for vaccination were established from blood of patients with advanced myeloid leukemia and were reactive with “specific” primate antisera against myeloid leukemic cells. Both sensitization to target cell antigens and substantial general increases in delayed hypersensitivity responses were recorded among immunized patients. Major immunologic complications (hypersensitivity and “autoimmune” phenomena) were observed in 10 patients. These complications were attributable to the BCG content of vaccines, and their incidence correlated with intensity of immunologic stimulation.

Data from cases in which intermittent busulfan therapy was used provided suggestive evidence that immunotherapy (either with BCG‐cell mixtures or with BCG alone) prolonged unmaintained remissions in one‐third of the patients. Among 48 “good‐risk” patients, there was an inverse correlation between intensity of immunologic stimulation and survival. The survival of 18 patients who received the most intensive vaccination schedule was identical to that of controls. Survival of the other 30 patients was significantly better (p = 0.03), with an increase of 2 years in median survival. Survival of 30 poor‐risk patients (24, most intensive vaccination schedule) was identical to that of controls.

We conclude that immunologic stimulation may produce worthwhile prolongation of life in CML but that overly aggressive schedules of immunotherapy abrogate this effect. Our experience raises the question whether results in other clinical trials of immunotherapy may have been adversely affected by excessive frequency or dosage of immunologic stimulants.
WHITE IMAGES OF BLACK SLAVES IN THE SOUTHERN UNITED STATES
Authors: Fredrickson George M.
Published: December 2006

Sambo, the typical plantation slave, was docile but irresponsible, loyal but lazy, humble but chronically given to lying and stealing; his behavior was full of infantile silliness and his talk inflated with childish exaggeration. His relationship with his master was one of utter dependence and childlike attachment; it was indeed this childlike quality that was the very key to his being. Although the merest hint of Sambo's “manhood” might fill the Southern breast with scorn, the child “in his place,” could be both exasperating and loveable8 (p. 82).
REVIEW OF CLINICAL CRITERIA OF BRAIN DEATH
Authors: Molinari Gaetano F.
Published: December 2006

Summary

A spectrum of descriptive definitions of death has been formulated based on a variety of observations using currently available clinical methods. These definitions vary widely in objectivity and some fail to distinguish the inevitability of death or irreversible coma from the fact of death. A hopeless prognosis may be an adequate criterion for termination of artificial resuscitation, but the bioethical issue involved is one of “passive” euthanasia and not brain death. A hopeless prognosis without a pronouncement of death itself would seem inadequate grounds to remove viable organs for transplantation.

When organ donation is contemplated, the declaration of death as a past event must be based on cerebral rather than on cardiovascular criteria. At this point in the history of the art and science of medicine, the highest degree of assurance that the brain is dead may be achieved in the shortest possible time, only by using multiple independently measured variables including clinical criteria, electrophysiologic criteria (the EEG), and assessment of cerebral circulation determined either directly or indirectly. As science and technology improve, the degree of objectivity and facility in obtaining objective criteria will also improve.
THE EEG IN DETERMINATION OF BRAIN DEATH
Authors: Bennett Donald R.
Published: December 2006

Summary

The values and limitations of electroencephalography in the determination of brain death have been reviewed. Electrocerebral silence per se does not necessarily mean total or irreversible brain dysfunction. In the state of brain death the EEG is always silent; however, ECS does not always mean brain death. Electroencephalography, when properly used, can be a most helpful aid to the physician. Clinical criteria alone for the establishment of brain death may lack specificity, and occasional cases with potentially remediable lesions may be overlooked. The diagnosis of brain death cannot be made by only one test. The physician has to make his decision based on the entire clinical picture and results of the studies that are available to him.
LOCAL MAXIMA IN GRADED GRAPHS OF EMBEDDINGS
Authors: Gross Jonathan L. , Tucker Thomas W.
Published: December 2006

Summary

This paper describes four natural ways in which the set of all orientable embeddings of a graph might be regarded as the vertices of a “graded graph.” A local maximum in any of these kinds of graded graphs is an embedding such that every “adjacent” embedding has fewer faces, and consequently, higher genus. Examples are presented to show that local maxima can arise in each of the four kinds of graded graphs, thereby undermining the hope for an obvious hill‐climbing algorithm. (Some hope for a more subtle hill‐climbing algorithm may survive.)
ON THE SPANNING TREES OF SELF‐DUAL MAPS
Authors: Tutte W. T.
Published: December 2006

Summary

A central reflex is a map on the sphere that is transformed into its dual map by reflection in the center. It is shown in [2] that the number T(M) of spanning trees of a central reflex M is a perfect square {X(M)}2. In the present paper we determine X(M) directly as the number of spanning trees of M in which no edge is equivalent, under central reflection, to the dual edge of another.

The paper is constructed as an expository article on the theory of dual planar maps. The proof that T(M) = {X(M)}2 is presented as an exercise in this theory.
ELECTRICAL FIELDS, CALCIUM GRADIENTS, AND CELL GROWTH
Authors: Robinson Kenneth R. , McCaig Colin
Published: December 2006

Summary

We have outlined the evidence that fucoid eggs and pollen tubes drive an electric current through themselves as they grow, alter (or initiate) their growth in response to an applied electrical field, and develop a calcium gradient during their growth with the region of highest calcium concentration being the growing point. New data have been presented to support the notion that it is this calcium gradient that is essential in the polarization process.

The fucoid egg (a free‐living cell) would not normally be subjected to an externally imposed electrical field. The fact that an imposed field can mimic the endogenous current must be viewed as somewhat fortuitous, since the effects of the imposed field on the membrane and the cytoplasm must be quite different from those of the endogenous field. The case of the growing neurite is quite different; we imagine that it might well be exposed to a field during normal neurogenesis. The following intriguing possibility is raised. Might the exogenous electrical field interact with an endogenous electrical field in the growing neurite? If so, the analogy between neurite extension and plant tip growth could be very close indeed. Our preliminary evidence that the neurites curve in response to a calcium ionophore gradient adds to the suspicion that these processes are similar. The idea is that the small voltage gradient sensed by a neurite would be amplified by the neurite's production of its own current which would involve local calcium entry. We are encouraged to attempt to suitably scale down the vibrating probe in an effort to measure such self‐generated currents.

Our finding that the muscle cells form their long axes at right angles to an electric field was made accidently and does not easily fit into the scheme that has been suggested for fucoid egg, pollen, and nerve. It may be that the field affects the orientation of a transverse tubule system which is somehow caused to form parallel to the field with the result that the long axis forms perpendicular to the field, but this is purely speculative at this point.

Finally, we should emphasize that our notion that an epithelially generated current may play a role in the orientation of nerves and muscle in embryonic Xenopus is not an exclusive one. We envision that such currents are only crude, initial controls and that other, subtler controls (such as local chemical gradients) will undoubtedly be involved in the finer control of these processes.
CELL TYPES IN LONG‐TERM PROPAGABLE CULTURES OF RAT LIVER*
Authors: Grisham J. W.
Published: December 2006

Under the conditions of this experiment, propagable hepatic epithelial cells in long‐term culture were derived from a small, nonparenchymal precursor cell present in the liver in vivo. Progeny of the nonparenchymal precursor cell weakly expressed some hepatocyte‐like properties in culture. Hepatocytes were not clonogenic under the conditions of this experiment. Propagable hepatic epithelial cells in long‐term culture probably originate from hepatic stem cells in vivo. Terminal biliary ductular cells are facultative stem cells for hepatocytes.
Is Ultrasound Monitoring of Follicular Growth Harmless?
Authors: DEMOULIN A. , BOLOGNE R. , HUSTIN J. , LAMBOTTE R.
Published: December 2006

Monitoring of the growth of ovarian follicles by ultrasound (US) is now frequently utilized in such procedures as hMG stimulation, artificial insemination, and in vitro fertilization. While experimental studies have demonstrated that ultrasound, when used at diagnostic intensities, is not toxic for cells or tissues,1 until now there has been no study concerning the effect of ultrasound waves on preovulatory follicles. Using ultrasound to determine the appropriate time for artificial insemination with donor semen (AID) in 1980, we have compared the pregnancy rates in two populations of AID patients (with US versus without US). The success rate is reduced in the US‐monitored group. Animal experiments confirm these results.
Monitoring Embryos after in Vitro Fertilization Using Early Pregnancy Factor
Authors: CHEN CHRISTOPHER , JONES WARREN R. , BASTIN FERN , FORDE CARON
Published: December 2006

The success of in vitro fertilization (I VF) and embryo transfer (ET) is dependent upon optimizing the efficiency of each step of the procedures that finally lead to embryo replacement. Much effort has been directed at improving oocyte recovery and fertilization through various regimes of ovarian stimulation, oocyte aspiration techniques, and cell culture technology. This has led to rates of oocyte recovery in the region of 80–90% and embryo transfer rates of 60–70%.1–4 By contrast, the pregnancy rate following ET is disappointingly low, being of the order of 15 to 20%.1,2,5,6 This seems to be the step at which most failures of IVF occur.
Patient Selection for in Vitro Fertilization: Physical and Psychological Aspects
Authors: JOHNSTON W. I. H. , OKE K. , SPEIRS A. , CLARKE G. A. , McBAIN J. , BAYLY C. , HUNT J. , CLARKE G. N.
Published: December 2006

In vitro fertilization (IVF) and embryo replacement offers the infertile couple a whole new dimension in their treatment. It offers new hope to the previously abandoned, and it has sparked a veritable frenzy of scientific endeavor among the reproductive biologists of the world. It has attracted extensive media attention, and, as each technological breakthrough is announced, the euphoria increases and the horizons seem endless.
The Effects of Vitamin C Supplementation on Blood and Hair Levels of Cadmium, Lead, and Mercury
Authors: CALABRESE EDWARD J. , STODDARD ANNE , LEONARD DENISE A. , DINARDI SALVATORE R.
Published: December 2006

Fifty‐two adult male subjects were randomly assigned to one of three possible treatment groups: supplemental ascorbic acid at one of two levels, 500 mg or 1000 mg, or a placebo. Hair and blood samples were taken before vitamin C or placebo supplementation was started and at monthly intervals thereafter for three months. Samples were analyzed for cadmium, lead, and mercury. Results indicate that vitamin C did not significantly affect levels of these metals in either hair or blood samples.
Hemopoietic Cell Progenitors in the Avian Embryo: Origin and Migrations
Authors: DIETERLEN‐LIÈVRE F.
Published: December 2006

The cellular events involved in the formation of hemopoietic progenitors during early embryogenesis are critical for the lifelong function of the blood‐forming system if, as is supposed, these progenitors arise during ontogeny and thereafter maintain their stock by self renewal. Several aspects of these events have been unravelled in recent years. Basic data on the interactions between stem cells and hemopoietic microenvironments have emerged from studies of the avian embryo by experimental approaches that are possible only in that class at the time of organogenesis. Interestingly, when it has been possible to devise appropriate experimental models, similar mechanisms have often been detected in mammals.

When early developmental processes are investigated, difficulties arise from the small contingent of cells available. Cell markers have made it possible to trace individual cells and thus to follow lineages through their phenotypic changes and their extensive migrations. In the avian embryo, a cell‐marking technique devised by N. Le Douarin in 19691 has become widely used for the study of various lineages. It consists in associating cells (or tissues, rudiments, embryonic territories) from two species, the chicken and the quail. Cell nuclei have a different appearance in these two species (Figure 1). In recent years, the distinction of blood cells according to species in this heterospecific system has become refined by the availability of two monoclonal antibodies with affinity restricted to the quail species and which recognize the hemangioblastic lineage, MB12 and QH13 (Figure 2). The hemangioblastic lineage comprises, on the one hand, endothelial cells, and on the other, blood cells and their progenitors. The points to consider about the ontogeny of the blood system are the relationships between stem cells and hemopoietic organ rudiments, the spatial and chronological origins of stem cells during ontogeny, the mechanisms through which they settle into the stromas of hemopoietic organs and the nature of the relationship between endothelial and hemopoietic cells.
Novel Molecules That Antagonize Leukotriene B4 Binding to Neutrophils
Authors: LIN ALICE H. , MORRIS JOEL , WISHKA DONN G. , GORMAN ROBERT R.
Published: December 2006

A series of LTB4 analogues have been synthesized that replace carbons 7–9 of the cis‐trans‐trans triene unit of LTB4 with a stable ring structure. Meta‐substituted pyridine analogues are more potent inhibitors than benzene or furan analogues. C‐1 alcohols are often more potent inhibitors than free carboxylic acids, and 5,6‐cis double bond compounds are more potent than 5,6‐trans compounds. Compounds such as these may prove to be useful in the treatment of inflammatory diseases.
Retroviral Pathogenesis: Unexpectedly High Levels of HIV‐1 RNA and Protein Synthesis in a Cytocidal Infection
Authors: ROBINSON H. L. , SOMASUNDARAN M.
Published: December 2006

I am pleased to be able to participate in this conference honoring Dr. Friend. I first met Dr. Friend in Tokyo in 1966 when she, I, and Dr. Duesberg shared a cab. At that time I was just beginning work with avian leukosis viruses, and my interests were focused on how these viruses transformed normal cells to malignant cells. At the time of this symposium honoring Dr. Friend and her research contributions, I am again starting a new area of research, work with human immunodeficiency virus type‐1 (HIV‐1). It is the early work of my laboratory with HIV‐1 that I am going to report on today. The work I will be describing was done by Dr. Mohan Somasundaran, a highly accomplished postdoctoral fellow in my laboratory.
The Molecular Control of Normal and Leukemic Hematopoiesis: Myeloid Cells as a Model Systema
Authors: SACHS LEO
Published: December 2006

Charlotte Friend was always optimistic and had a wide range of interests in different subjects. Her death is a tragedy for all of us. It is a loss to the wider scientific community, but even more so for those with whom she was most closely associated. Our meetings will not be the same without her. She and I often agreed in discussions, and I trust that what I have to say today would have met with her approval.
Studies of Cachexia in Parasitic Infection
Authors: TRACEY KEVIN J. , CERAMI ANTHONY
Published: December 2006

Chronic illness caused by infection with parasites, viruses, or bacteria is frequently associated with a potentially fatal syndrome termed “cachexia.” The stricken host dies from progressive weight loss, anemia, immune suppression, and terminal organ injury, even when the invasive burden may be relatively small. Until recently the biochemical basis of these harmful effects of infection‐associated cachexia was not understood. They are now known to be mediated primarily by endogenous factors released in response to invasive infection. The search for these mediators led to the identification, isolation, and cloning of the cytokine known as cachectin/TNF (tumor necrosis factor).

Investigation of the biological effects of cachectin/TNF subsequently confirmed its role as a mediator of cachexia. Further studies revealed that cachectin is also an important mediator of septic shock, another syndrome of injurious host responses elicited by acute bacterial infection. The realization that endogenous factors, produced acutely or chronically during infection and inflammation, may mediate lethal syndromes in the host has advanced our understanding of the pathophysiology of infectious illnesses, and led to the investigation of novel treatment modalities. In this paper we will briefly review the history of cachectin/TNF, and discuss its role as an endogenous mediator of the hosts' responses to infection.
SOME PROPERTIES OF FAMILIES OF EXCITONIC QUASIPARTICLES
Authors: Birman Joseph L. , Artoni M. , Wang Bing Shen
Published: December 2006

Three closely related types of excitonic quasiparticles have been recently studied: polaritons, phonoritons and photoritons. We show that the well known polariton displays frequency‐tunable intrinsic squeezing. Related to this is a new Quantum Optics Extinction Theorem. The phonoriton is associated with a “reconstruction” of the dispersion equation for the parent‐polariton: tests have so far proven elusive. Two new experiments are proposed and analyzed for identifying the phonoriton: Non‐Linear Resonance Brillouin Scattering, and Non‐Linear Reflectivity. Some remarks are made about the photoriton.
LOCAL MOMENTS NEAR THE METAL‐INSULATOR TRANSITION
Authors: Sachdev Subir
Published: December 2006

This paper reviews recent progress in understanding the metal‐insulator transition in a system of spin‐1/2 interacting electrons in the presence of a non‐magnetic random potential. Using results of recent experiments in doped semiconductors, it is argued that the metallic state near the transition can be described by a phenomenological two‐fluid model of local moments and itinerant quasiparticles. A mean‐field calculation on a disordered Hubbard model which justifies this two fluid model is described. Recent advances in the non‐linear sigma model description of the transition are also discussed.
Single Base Substitution in Codon 74 of the MD Rat Myelin Proteolipid Protein Genea
Authors: SIMONS R. , RIORDAN J. R.
Published: December 2006

The myelin‐deficient (md) rat is one of several X‐linked animal mutants that have severe dysmyelination in the central nervous system. It appears in all to be the result of mutations in the myelin proteolipid protein gene which is located on the long arm of the X‐chromosome. To identify the md rat mutation, we isolated and sequenced cDNAs corresponding to PLP and DM‐20 mRNAs from the brain of hemizygous affected males. The only consistent sequence difference between these and normal rat sequences was the substitution of a C for an A at the first position of codon 74, resulting in a threonine to proline amino acid change. The presence of this helix‐breaking amino acid in the second hydrophobic α‐helical segment of the protein might be expected to influence its ability to interact with the membrane. PCR amplification and sequencing of the corresponding genomic regions were used to confirm the presence of the single base change in the hemizygote and both normal and mutant versions in the heterozygotes. It is interesting that this change, like those detected in other X‐linked myelin disorders, involves an amino acid replacement within a hydrophobic α‐helical segment of the PLP protein. Disruption of these structures apparently has severe consequences for the ability of PLP to contribute normally to myelination.
On Cleavability of Topological Spaces over R, Rn, and Rω
Authors: ARHANGEL ALEXANDER V.
Published: December 2006

A space X is said to be cleavable over a space Y if for every subset A of X there exists a continuous mapping f : X → Y such that A = f−1f(A). It is shown that a compact space X is cleavable over the space R of real numbers if and only if X is homeomorphic to a subspace of R. It is also proved that if a space X is cleavable over Rn, where n is a natural number, and V is a subspace of X homeomorphic to Rn, then V is open in X. Every infinite connected subset of any space cleavable over R is shown to have a nonempty interior.
ℵ‐completeness as E‐compactness via the Uniform Dimensiona
Authors: CONCILIO A. DI
Published: December 2006

Let ℵ be an infinite cardinal number and ℛ (ℵ, 1) a complete metric space of density ℵ and uniform dimension 1 uniformly universal in the class of all metric spaces of density ≤ℵ and uniform dimension ≤ 1. The ℵ‐uniformity of a Tychonoff space X, which is generated by all open normal coverings of X with cardinality ≤ℵ, is complete iff X can be embedded as a closed subspace in a Cartesian product of copies of ℛ (ℵ, 1).
Sum and Mapping Theorems for B(D, ω0)‐Refinable Spaces
Authors: FAST STEPHEN H.
Published: December 2006

It is known that closed maps preserve θ‐refinability and subparacompactness. It is also known that perfect maps preserve weak θ‐refinability. Some results toward a perfect mapping theorem for B(D, ω0)‐refinability are given, as well as some results on sum theorems for this property.
On Free p‐Compact Groups
Authors: GARCIA SALVADOR
Published: December 2006

A. R. Bernstein introduced the concept of p‐compactness (p∈ω*). Years later, W. W. Comfort defined a (pre)‐order ≤C on ω* by p ≤C q iff every q‐compact space is p‐compact. It is natural to consider the relation ≤GC on ω* given by p≤GC q iff every q‐compact topological group is p‐compact. It is shown that ≤RK≤C, and ≤GC coincide on the set of weak P‐points of ω* (≤RK denotes the Rudin–Keisler order on ω*), and that ≤C and ≤GC have several properties in common, but the question whether ≤C=≤GC still remains unsolved. Some properties of free M‐compact groups (M⊆α*) are also studied. In particular, it is shown that if α is a regular infinite cardinal and X is < α‐bounded, then X is a closed subspace of the free < α‐bounded topological (Abelian) group over X.
Preimages of Spaces Having a Base of Countable Order
Authors: GRABNER E. M.
Published: December 2006

The main theorem characterizes the quasi‐perfect and perfect preimages of T1‐spaces having a base of countable order. The preimages of T1‐spaces having a base of countable order are connected with the preimages of T1‐spaces having a primitive base under the same type of mappings.
The Fell Topology on C(X)
Authors: HOLÁ L̆BICA , MCCOY R. A.
Published: December 2006

The space C(X, Y) of continuous functions from a topological space X to a Hausdorff space Y can be thought of as a subset of the hyperspace of closed subsets of X × Y by identifying each element of C(X, Y) with its graph. A study is made of C(X, Y) with the topology inherited by the Fell topology on hyperspaces. The emphasis is on real‐valued functions where Y=ℝ, in which case the function space is denoted by C(X). A number of characterizations are given of topological properties of C(X) and C(X, Y) in terms of properties on X (and Y). These properties often turn out to involve both local compactness and connectedness type of conditions.
Nonarchimedean Normed Linear Spaces
Authors: REN GUANSHEN
Published: December 2006

Important theorems of valuation theory and classic functional analysis that have known analogues in the theory of nonarchimedean normed linear spaces over rank‐one valued fields are considered in the more general context of nonarchimedean normed linear spaces over fields of arbitrary rank. Maximal completeness, pseudocompleteness, and spherical completeness are shown to be equivalent. Versions of Riesz's lemma and the Hahn–Banach theorem are given. The utility of considering ordered (value) groups as being embedded in their Dedekind completions is demonstrated.
Big Sets
Authors: SHELL NIEL
Published: December 2006

A relation between two ring topologies on a field that implies neighborhoods of zero in one topology may reasonably be considered to consist of elements that are large in the other topology.
Products of Locally Pseudocompact Topological Groupsa
Authors: TRIGOS‐ARRIETA F. JAVIER
Published: December 2006

An old theorem of Comfort and Ross to the effect that the product of any number of pseudocompact groups remains pseudocompact is generalized, and a brief survey of some known results of locally pseudocompact groups is given. The product of any number of pseudocompact regularly closed subspaces of topological groups is proved to be pseudocompact. A corollary is obtained that the classes of locally pseudocompact groups and of locally compact groups behave similarly with respect to products. Additional known facts concerning products of functionally bounded sets that are connected with the results are briefly surveyed.
The Work of Mary Ellen Rudina
Authors: TALL FRANKLIN D.
Published: December 2006

An overview and historical perspective of the work of Mary Ellen Rudin is given.
Aberrant Phosphoinositide Metabolism in Alzheimer's Diseasea
Authors: SHIMOHAMA SHUN , FUJIMOTO SADAKI , TRESSER NANCY , RICHEY PEGGY , PERRY GEORGE , WHITEHOUSE PETER J. , HOMMA YOSHIMI , TAKENAWA TADAOMI , TANIGUCHI TAKASHI , SUENAGA TOSHIHIKO , KIMURA JUN
Published: December 2006

Since phosphoinositide‐specific phospholipase C (PLC) is one of the key molecules in signal transduction, its involvement was assessed in Alzheimer's disease (AD). The phosphatidyl‐inositol (PI)‐specific PLC activity in the Alzheimer cytosolic and participate fractions was not significantly different from that in the control fractions. The PI‐specific PLC activity as a function of the free Ca2+ concentration was also similar between control and Alzheimer brains. These results suggest that the PI‐specific PLC activity is not altered in AD. Immunostaining of a specific antibody against the PLC isozyme, PLC‐δ, demonstrated that this enzyme was abnormally accumulated in neurofibrillary tangles (NFT), the neurites surrounding senile plaque (SP) cores, and neuropil threads in AD brains. Western blot analysis confirmed that PLC‐δ was concentrated in the paired helical filament (PHF)‐rich fraction of AD brains. PLC‐δ marked the same neurons containing τ immunoreactivity and yet τ and PLC‐δ often marked different structures within the same neuron, with τ more clearly on NFT and PLC‐δ covering it superficially. The double stain with PLC‐δ and basic fibroblast growth factor (bFGF) binding suggest that PLC‐δ is an intracellular marker, showing little overlap with bFGF binding, an extracellular marker. All of this was consistent with the electron microscopy, with PLC‐δ being NFT associated. Antibodies to other PLC isozymes did not produce positive immunostaining of these pathologic structures. Moreover, diffuse and amorphous deposits of PLC‐δ were found to precede the accumulation of fibrillary deposits. These results suggest that PLC‐δ accumulation plays a possible role in the formation of intraneuronal inclusions in AD.
Heat‐shocked Neuronal PC12 Cells Reveal Alzheimer's Disease—associated Alterations in Amyloid Precursor Protein and Tau
Authors: JOHNSON G. , REFOLO L. M. , WALLACE W.
Published: December 2006

The Alzheimer's disease (AD) brain contains many abnormal protein modifications. These include the abnormal processing of amyloid precursor protein (APP) to form the amyloidogenic β/A4 peptide and the abnormal phosphorylation of tau to form A68, the major constituent of the neurofibrillary tangle. In addition, many of the biochemical alterations found in the AD brain are also found in heat‐shocked or stressed cells. We used heat‐shocked neuronal PC12 cells to investigate the effects of stress on APP and tau. We found that by simply exposing neuronal PC12 cells to an elevated temperature (45°C) for 30 minutes, they exhibited several features characteristic of the heat shock response. These included a 45% reduction in total protein synthesis, the induction of heat shock protein (hsp) 72, and increased phosphorylation of the protein synthesis initiation factor eIF‐2 α. The heat‐shocked cells also exhibited alterations in the metabolism and phosphorylation of APP. Under heat shock conditions, we found two additional APP‐like polypeptides not present in controls and a significant decrease in the phosphorylation state of APP. We also found that an A68‐like protein is formed in neuronal PC12 cells when subjected to elevated temperature. This A68‐like protein was formed with heat shock even in the absence of protein synthesis, suggesting that its production occurred post‐translationally. The tau/A68 polypeptides were identified as phosphoproteins, and the phosphorylation of tau to form A68 was reversed with recovery of the cells from heat shock. Immunoprecipitation of lysates from heat shocked cells with antibodies to hsp72/73 resulted in co‐precipitation of tau, but not A68 with hsp72 indicating a stable complex formation between these two proteins. These results suggest that heat shock proteins may play either a protective or promoting role in the formation of A68 and/or the amyloidogenic C‐terminal fragment of APP.
Phospholipid and Phospholipid Metabolites in Rat Frontal Cortex Are Decreased following Nucleus Basalis Lesionsa
Authors: HOLMES TODD C. , NITSCH ROGER M. , ERFURTH ANDREAS , WURTMAN RICHARD J.
Published: December 2006

Membrane phospholipid metabolism is abnormal in Alzheimer's disease (AD) brain. Phosphatidylcholine and phosphatidylethanolamine levels are decreased as are choline and ethanolamine, while glycerophosphocholine (GPC) and glycerophosphoethanolamine are increased.1 To develop a rat model for these changes, we examined the effects of unilateral lesion of the cholinergic nucleus basalis (nBM) with ibotenic acid (10 mg/ml in PBS, 0.5 μl) and sham lesion on frontocortical phospholipid, choline and GPC. After one week, choline acetyltransferase activity in frontal cortex was decreased (26%, p < 0.005, n = 14) on the nBM ibotenate‐lesion side relative to the contralateral side, while there were no differences following the nBM sham‐lesion. Levels of membrane phospholipids (nmol/mg protein) in adjacent frontal cortex sections exhibited concomitant decreases (13%, p < 0.05, n = 14) on the nBM ibotenate‐lesion side, while there were no differences following the nBM sham‐lesion. Tissue nBM ibotenate‐lesion frontocortical choline and GPC levels were also decreased relative to those in control tissues (choline: 21%, p < 0.05, n = 14; GPC: 10%,p < 0.05, n = 14), while nBM sham‐lesion showed no effect. Muscarinic receptor sensitivity in frontal cortex following nBM ibotenate‐lesion was increased, as measured by carbachol‐sdmulated inositol phosphate production (p < 0.001, n = 12), indicating that increased receptor mediated phospholipid hydrolysis in cortex may occur following nBM ibotenate‐lesion. These data suggest that impaired cholinergic transmission alters phospholipid metabolism in cholinergic target regions.
Behavioral Effects of Cholinergic Graftsa
Authors: RIDLEY R. M. , BAKER H. F.
Published: December 2006

ABSTRACT: Experimental work in animals and, to a more limited extent, in humans, has demonstrated that the cholinergic system is involved in mechanisms which control learning and memory. Since there is cholinergic loss in a variety of dementing illnesses, any treatment designed to alleviate the mental symptoms of these diseases must address the issue of cholinergic dysfunction even if other treatments are also required to overcome other neurotransmitter imbalances. Work in rodents has demonstrated that cholinergic‐rich fetal neural tissue transplants can, under certain circumstances, alleviate the behavioral effects of cholinergic lesions or of cholinergic decline associated with aging. More complex cognitive testing can be achieved using primates and, in this case, the common marmoset is a suitable species to use because its rapid and reliable reproductive rate aids the provision of appropriate transplant tissue. Marmosets with transection of the fornix are deprived of a cholinergic input into the dentate gyrus, posterior hippocampus and entorhinal cortex and are specifically impaired on learning tasks which require remembering a rule of responding (non‐evaluative memory). Transplantation of cholinergic‐rich fetal septal tissue into the hippocampus of such animals completely restores their ability to learn this type of task, whereas transplantation of cholinergic‐poor fetal hippocampal tissue into the same area produces no such improvements. These results demonstrate that where a learning impairment is produced by a relatively simple procedure which has a major effect on one neurotransmitter, that function can be restored by transplantation of tissue containing that neurotransmitter even where the impairment consists of a very “high level” cognitive dysfunction.
PKC Translocation in Rat Brain Cortex Is Promoted in Vivo and in Vitro by α‐Glycerylphosphorylcholine, a Cognition‐enhancing Druga
Authors: GOVONI S. , BATTAINI F. , LUCCHI L. , PASCALE A. , TRABUCCHI M.
Published: December 2006

Protein kinase C (PKC) activity was measured in soluble and particulate fractions of rat individual brain areas after treatment with α‐glycerylphos‐phorylcholine (GPC), a cognition‐enhancing drug which promotes acetylcholine synthesis and release. The drug induced both in vivo and in vitro PKC translocation. In vivo, an increase of paniculate PKC activity was observed 1 hour following the acute oral administration of a behaviorally active dose (600 mg/kg); the effect was transient. In vitro, GPC promoted PKC translocation in cortical slices at concentrations as low as 50 nM; the concentration‐response curve was bell shaped. The increased PKC activity may be related to the cortical effects of GPC.
Oral Cytidine 5′‐Diphosphate Choline Administration to Rats Increases Brain Phospholipid Levels
Authors: AGUT J. , G.‐COVIELLA I. LOPEZ , ORTIZ J. A. , WURTMAN R. J.
Published: December 2006

Exogenous cytidine 5′diphosphocholine (CDF‐choline) is completely metabolized to circulating cytidine and choline. Both compounds enter the brain and can be used in phosphatidylcholine (PC) synthesis via the Kennedy (CDP‐choline) cycle. We administered oral CDP‐choline to 12 month‐old rats (500 mg/kg/day) for 21, 42, or 90 days to determine whether this treatment would alter brain levels of PC and the other structural phospholipids, phosphatidylserine (PS) and phosphatidylethanolamine (PE). After 42 days, brain PC levels increased significantly (p < 0.01) by 23.3%; after 90 days PC increased by 30% (p < 0.01), PS by 37.2% (p < 0.01), and PE by 13% (not significant). The ratios of each of the phospholipids to total membrane phospholipids were unchanged. These data demonstrate that repeated oral CDP‐choline administration can increase the amounts of phospholipids in brain membranes, thus providing a rationale for using this compound in brain diseases that damage neurons.
TOWARDS A THEORY OF QUARK AND LEPTON MASSES*
Authors: Hall L. J.
Published: December 2006

Has any progress been made on understanding and predicting the 13 parameters which describe the observed masses and mixing angles of the quarks and leptons? Arguments are given in favor of pursuing schemes in which grand unified and family symmetries provide many relations among these 13 parameters. A sequence of simple assumptions leads to a supersymmetric SO(10) theory with 8 predictions: tan β, mt, Vcb, ms, ms/md, mu/md, Vub and the amount of CP violation J. These predictions are presented, together with experiments which will test them.
Convergence Space Extensions
Authors: KENT D. C. , REED E. E.
Published: December 2006

ABSTRACT. Some, but certainly not all, convergence space extensions can be obtained by completing an appropriate Caunchy structure. A more general completion theory is developed, in which “Cauchy structures” are replaced by “stack systems,” and it is shown that every convergence space extension via a dense embedding can be described as a completion derived from an appropriate stack system.
Products of ACRIN Spaces
Authors: LaBERGE TIMOTHY J.
Published: December 2006

ABSTRACT. Products of spaces X and Y with the property that every continuous regular image of the product is normal are investigated, and the conclusion that there are fewer such spaces than might be suspected arrived at. In fact, either X and Y are Lindelöf, or X is countably compact, Y is compact, and t(Y) is small. In a first effort to find a partial converse to the second case, Nogura's result on the normality of the product of an ordinal with a compact space is extended.
Extensions of Discrete Spaces
Authors: PORTER JACK R.
Published: December 2006

ABSTRACT. A simple method is developed that embeds an H‐closed space as the remainder of an H‐closed extension of a discrete space; one of the many generated extensions will have the same cardinality, weight, density, and character as the original space. Also, an example of an H‐closed space (an extension of a discrete space) is constructed in which the number of H‐closed subspaces is less than the number of H‐sets.
Autohomeomorphisms of Thin‐Tall Locally Compact Scattered Spaces in ZFC
Authors: ROITMAN JUDITH
Published: December 2006

ABSTRACT. For many uncountable groups G, there is a thin‐tall locally compact scattered space (equivalently, thin‐tall superatomic Boolean algebra) whose nontrivial autohomeomorphism (equivalently, automorphism) group is G. Such groups include ω!, the free group on ω1 generators, and the free commutative group on ω1.
Lower Density Topologiesa
Authors: ROSE D. A. , JANKOVIĆ D. , HAMLETT T. R.
Published: December 2006

Abstract

By considering lower density operators and their induced topologies in a general setting, some results of S. Scheinberg and E. Ľazarow et al. are unified and generalized. It is also shown that every σ‐finite complete measure space (X, M, m) has a lower density operator and that every such operator induces a topology making X a category measure space in the sense of J. C. Oxtoby, except that the measure need not be finite. One consequence is that category σ‐finite measure spaces must have the countable chain condition. Also, for every topological space (X, |Gt), there is a lower density operator on the σ‐field of sets having the property of Baire (relative to the σ‐ideal of meager sets). Further, in both the “measure” and “category” contexts, all induced lower density topologies have simple form. Finally, it is shown that the deep. J‐density operator on the σ‐field of subsets of the real line having the property of Baire is not a lower density operator.
A Problem in the Open Disc
Authors: BALOGLOU GEORGE , TRACY PHIL
Published: December 2006

ABSTRACT. An open problem relating measure and category to a convexity‐like property is presented.
Topological Measures of Systems of Sets
Authors: BANKSTON PAUL
Published: December 2006

ABSTRACT: If X is an infinite set, we may topologize the power set of X naturally so that systems of subsets of X can be described in the language of Baire category. Systems we consider include: subalgebra lattices of algebraic structures; topologies; filters; and families of almost disjoint sets.
Topological Linearly Ordered Spaces Determined by Pervin's Quasi‐uniformity
Authors: FERRER J. , GREGORI V.
Published: December 2006

ABSTRACT: In this paper we study those uniform linearly ordered spaces that are determined by Pervin's quasi‐uniformity. In particular, we show that the space of all countable ordinals is determined by a unique quasi‐uniformity.