bluuebunny/crossref_metadata_2025 huggingface dataset:
Serological Visualization of Interleukin 2
Authors: Steinmann Gerhard , Conlon Paul , Hefeneider Steven , Gillis Steven
Published: October 2006

Interleukin 2, a lymphokine that acts as a second signal of cellular immune response by way of its action as a T-cell growth factor, was morphologically identified by immunoperoxidase staining. With the use of a monoclonal antibody to interleukin 2 and several complex-forming antisera, the lymphokine was readily distinguished in cytocentrifuge preparations of peripheral blood leukocytes stimulated with a T-cell mitogen. When preparations of cloned interleukin 2 producer and responder cells were stained by the same procedures, discrete patterns of both responder and producer cell phenotypes were revealed. Interleukin 2 producer T cells exhibited a characteristic intense, ringlike cytoplasmic staining, whereas the responder cells (as exemplified by interleukin 2-dependent cell lines) exhibited a less intensive, spotlike membrane staining. In addition, intense membrane localization of interleukin 2, reminiscent of potential capping phenomena, could be observed in stained preparations of cloned responder cells.
Monoclonal Antibodies Reveal the Structural Basis of Antibody Diversity
Authors: Teillaud Jean-Luc , Desaymard Catherine , Giusti Angela M. , Haseltine Barbara , Pollock Roberta R. , Yelton Dale E. , Zack Donald J. , Scharff Matthew D.
Published: October 2006

Hybridoma technology has made it possible to introduce into continuous culture normal antibody-forming cells and to obtain large amounts of the immunoglobulin produced by each of these cells. Examination of the structure of a number of monoclonal antibodies that react with a single antigen has provided new information on the structural basis of the specificity and affinity of antibodies. Comparisons of families of monoclonal antibodies derived from a single germ line gene revealed the importance of somatic mutation in generating antibody diversity. Monoclonal antibodies that react with variable regions of other monoclonals allow the further dissection and modulation of the immune response. Finally, the continued somatic instability of immunoglobulin genes in cultured antibody-forming cells makes it possible to determine the rate of somatic mutation and to generate mutant monoclonal antibodies that may be more effective serological reagents.
Identification and Location of Brain Protein 4.1
Authors: Goodman Steven R. , Casoria Linda A. , Coleman Diane B. , Zagon Ian S.
Published: October 2006

Protein 4.1 is a membrane skeletal protein that converts the low-affinity interaction between spectrin and actin into a high-affinity ternary complex of spectrin, protein 4.1, and actin that is essential to the structural stability of the erythrocyte. Pig brain was shown to contain an 87-kilodalton immunoreactive analog of protein 4.1 that has partial sequence homology with pig erythrocyte protein 4.1 and the same location as spectrin in the cortical cytoplasm of neuronal and glial cell types of the cerebellum.
Sedimentation Field Flow Fractionation of DNA's
Authors: Schallinger L. E. , Yau W. W. , Kirkland J. J.
Published: October 2006

Sedimentation field flow fractionation (SFFF) is a method for purifying and providing mass or size distribution information on samples containing particulates or soluble macromolecules. Since SFFF separations are based on simple physical phenomena related to first principles, molecular weight (or particle sizes) can be determined without calibration standards. SFFF is a gentle technique suited for fractionating biomolecules. Studies with the fragile λ DNA (molecular weight, 33 × 10
6
) and smaller supercoiled plasmids have shown that these materials are not altered during SFFF separation; molecular weights and conformation remain unchanged, and biological activity is not reduced. Recoveries of nucleic acids approach 100 percent. Typically, components with about 20 percent difference in mass can be separated essentially to baseline if required. Fractionation time is usually independent of molecular weight, and separations often can be carried out within an hour.
H-2 Antigen Class: Effect on Mouse Islet Allograft Rejection
Authors: Morrow Charles E. , Sutherland David E. R. , Steffes Michael W. , Najarian John S. , Bach Fritz H.
Published: October 2006

Rejection of mouse pancreatic islet allografts occurred in a high percentage of donor recipient combinations identical for H-21-region antigens and differing at H-2K and H-2K + H-2D without I-region disparities. The results suggest that disparities in major histocompatibility complex antigens of class I (H-2K and H-2D) alone are capable of eliciting islet allograft rejection, and that lack of a stimulus from class II (I-region) alloantigens does not ensure permanent islet allograft survival.
Estradiol Fatty Acid Esters Occur Naturally in Human Blood
Authors: Janocko Laura , Hochberg Richard B.
Published: October 2006

Treatment of nonpolar ether extracts of human female blood with mild alkali produced more immunoassayable estradiol than the unhydrolyzed extract. Analysis of the serum extracts showed that the substance which released immunoreactive estradiol after hydrolysis has chromatographic properties identical to those of fatty acid esters of estradiol esterified at carbon 17. The physiological role of these previously unknown endogenous esters might be inferred from their structural similarity to synthetic drugs used therapeutically for their prolonged estrogenic action.
Extrapulmonary Gas Exchange Enhances Brain Oxygen in Pigeons
Authors: Bernstein Marvin H. , Duran Harry L. , Pinshow Berry
Published: October 2006

Blood in mouth, nose, and eye tissues of birds cools by evaporation, then flows to a cephalic vascular heat exchanger, the ophthalmic rete. There, acting as a heat sink, blood from the evaporative surfaces cools arterial blood flowing countercurrent to it toward the brain. The brain thus remains cooler than the body core. Data for unanesthetized domestic pigeons (Columba livia) suggest that in addition to losing heat, blood perfusing the evaporative surfaces also exchanges oxygen and carbon dioxide with air. In the heat exchanger, this blood apparently gives up oxygen to, and gains carbon dioxide from, arterial blood. The consequent increase in oxygen and decrease in carbon dioxide in the brain's arterial blood enhance diffusion of these gases in, and oxygen supply to, the brain. Such events may help birds maintain the brain's oxygen supply during the high systemic demand of exercise and at the reduced oxygen availability of high altitude.
Neural Mechanisms of Sound Localization in an Echolocating Bat
Authors: Fuzessery Zoltan M. , Pollak George D.
Published: October 2006

The mustache bat emits a three-harmonic echolocation pulse. At the external ear, large interaural intensity differences are generated only when a sound originates within a limited area of two-dimensional space, and this area is different for each pulse harmonic. As a consequence, the external ear generates pronounced binaural spectral cues containing two-dimensional spatial information. This information is encoded in the inferior colliculus by neurons tuned to one of the harmonics and sensitive to interaural intensity differences.
Detection of High Molecular Weight Forms of Platelet-Derived Growth Factor by Sequence-Specific Antisera
Authors: Niman Henry L. , Houghten Richard A. , Bowen-Pope Daniel F.
Published: October 2006

Antisera to synthetic peptides representing sequences of both chains of platelet-derived growth factor (PDGF) were used to structurally analyze PDGF isolated from outdated human platelets and PDGF-like proteins in normal and transformed cells. Most PDGF isolated from platelets did not contain the carboxyl portion of PDGF-2 in contrast to p20
sis
, the major form of p28
sis
detected in simian sarcoma virus-transformed cells. In addition, higher molecular weight forms of molecules containing PDGF-1 and PDGF-2 sequences were detected in all cell lines tested. These lines were heterogeneous with respect to species, cell type, and transforming agent.
Interferon-β-Related DNA Is Dispersed in the Human Genome
Authors: Sagar Anurag D. , Sehgal Pravinkumar B. , May Lester T. , Inouye Masayori , Slate Doris L. , Shulman Lester , Ruddle Frank H.
Published: October 2006

Interferon-β
1
(IFN-β
1
) complementary DNA was used as a hybridization probe to isolate human genomic DNA clones λB3 and λB4 from a human genomic DNA library. Blot-hybridization procedures and partial nucleotide sequencing revealed that λB3 is related to IFN-β
1
(and more distantly to IFN-α
1
). Analyses of DNA obtained from a panel of human-rodent somatic cell hybrids that were probed with DNA derived from λB3 showed that λB3 is on human chromosome 2. Similar experiments indicated that λB4 is not on human chromosomes 2, 5, or 9. The finding that DNA related to the IFN-β
1
gene (and IFN-α
1
gene) is dispersed in the human genome raises new questions about the origins of the interferon genes.
Genetically Obese Mice: Resistance to Metastasis of B16 Melanoma and Enhanced T-Lymphocyte Mitogenic Responses
Authors: Thompson Carl I. , Kreider John W. , Black Paul L. , Schmidt Thomas J. , Margules David L.
Published: October 2006

The metastasis of B16 melanoma cells differed significantly in obese (
ob
/
ob
) and lean (+/?) female mice of strain C57BL/6J. When the mice were inoculated subcutaneously with melanoma cells at 10 to 11 months of age, the primary tumor grew more slowly in obese than in lean littermates and the frequency of lung metastasis was greatly reduced. When the mice were injected with the cells at 4 to 7 months, the primary tumor grew at the same rate in obese and lean mice, but the obese mice again showed a significantly reduced frequency of lung metastasis. That this effect was related to an enhanced immunocompetence in obese mice was supported by the finding that splenic lymphocytes of
ob
/
ob
mice showed three times the proliferative response to the T-cell mitogen concanavalin A compared with the proliferative response of lean control mice. The
ob
/
ob
mouse may provide a model for the study of enhanced immunocompetence in obese individuals.
Chromosome 4
Jt
Gene Controls Murine T Cell Surface I-J Expression
Authors: Hayes Colleen E. , Klyczek Karen K. , Krum David P. , Whitcomb Robert M. , Hullett Debra A. , Cantor Harvey
Published: October 2006

Data are presented suggesting a resolution to the paradox concerning the murine response subregion I-J, which encodes a suppressor T cell marker. The controversy arose when sequences corresponding to I-J DNA were not found in the central immune response region described by immunogeneticists. New evidence is presented that T cell surface I-J expression results from the action of at least two complementing genes. One gene is within the H-2 region on chromosome 17; the second gene, termed
Jt
, is on chromosome 4. The two recombinant mouse strains B10.A(3R) and B10.A(5R) originally used to define the I-J subregion apparently differ not within the H-2 region but elsewhere.
Phosphorylation Events During Müllerian Duct Regression
Authors: Hutson John M. , Fallat Mary E. , Kamagata Shoichiro , Donahoe Patricia K. , Budzik Gerald P.
Published: October 2006

Regression of the fetal rat Müllerian duct in vitro was stimulated by sodium fluoride in the absence of Müllerian inhibiting substance. The action of Müllerian inhibiting substance was inhibited by sodium vanadate, adenosine 5′-triphosphate, and several related nucleotides in the presence of manganese ions. Epidermal growth factor specifically inhibited the substance, but only with manganese ions present. Insulin, platelet-derived growth factor, and nerve growth factor had no effect. These results suggest that dephosphorylation of membrane proteins mediates the action of Müllerian inhibiting substance.
Pregnancy Interception with a Combination of Prostaglandins: Studies in Monkeys
Authors: Wilks John W.
Published: October 2006

Treatment with combinations of synthetic prostaglandins, one with an ovarian site of action and one with a uterine site of action, terminated pregnancy in all rhesus monkeys given the injection on day 28 of fertile menstrual cycles. Single prostaglandins, even at higher doses, interrupted pregnancy in only one-third of the monkeys. The most effective treatment, 5-oxa-17-phenyl-18,19,20-trinor prostaglandin F
1α
methyl ester plus 9-deoxo-16,16-dimethyl-9-methylene prostaglandin E
2
, promptly intercepted early pregnancy after a single administration and without side effects.
Mercury Concentrations in Pacific Hake,
Merluccius productus
(Ayres), as a Function of Length and Latitude
Authors: Cutshall Norman H. , Naidu Janakiram R. , Pearcy William G.
Published: October 2006

Mercury concentrations in Pacific hake increase with fish size and with the latitude of collection. While the mercury-size trend is consistent with data for other species, the latitudinal trend is opposite to that reported for other fishes over the same geographical area. Consequently, latitudinal trends of mercury concentrations in fishes do not necessarily indicate trends of mercury concentrations in water. Food habits and metabolism may cause the observed variations.
Physiological Basis of Anisometropic Amblyopia
Authors: Eggers Howard M. , Blakemore Colin
Published: October 2006

In the visual cortex of kittens that have received their only visual experience while wearing a high-power lens before one eye, most neurons are dominated by input from the normal eye. Moreover, contrast sensitivity and resolving power are lower for stimulation through the originally defocused eye, mimicking psychophysical results from human anisometropic amblyopes.
Iconic Storage: The Role of Rods
Authors: Adelson Edward H.
Published: October 2006

The hypothesis that rods mediate iconic storage was tested by presenting letters of one color against a field of another. The colors were chosen to be discriminable only by the cones, only by the rods, or both. Under dark adaptation, the rods had little if any effect on partial-report advantage; however, they were important in determining the phenomenal persistence of the stimulus. Under light adaptation, the rods played no apparent role in either type of persistence.
Biotinated Probe Containing a Long-Terminal Repeat Hybridized to a Mouse Colon Tumor and Normal Tissue
Authors: Royston Moira E. , Augenlicht Leonard H.
Published: October 2006

The cloned complementary DNA pMCT-1, which contains an intracisternal A particle long-terminal repeat, is more highly expressed in a mouse colon tumor than in the normal mouse colon. In situ hybridization of biotin-substituted pMCT-1 to fixed frozen sections shows that expression of pMCT-1 is seen throughout the tumor and is highly heterogeneous on a cellular basis, while expression is undetectable in any cell in the normal colonic mucosa.
Light-Regulated Expression of a Pea Ribulose-1,5-Bisphosphate Carboxylase Small Subunit Gene in Transformed Plant Cells
Authors: Broglie Richard , Coruzzi Gloria , Fraley Robert T. , Rogers Stephen G. , Horsch Robert B. , Niedermeyer Jeanne G. , Fink Cynthia L. , Flick Jeffery S. , Chua Nam-Hai
Published: October 2006

A pea nuclear gene encoding the small subunit of ribulose-1,5-bisphosphate carboxylase was inserted into the tumor-inducing (Ti) plasmid of Agrobacterium tumefaciens and transferred into petunia cells by in vitro transformation. The transferred pea rbcS gene is expressed in petunia cells under the transcriptional control of its own promoter in a light-dependent fashion similar to that observed in pea leaves. In contrast, a nonphotosynthetic chimeric gene containing a nopaline synthase promoter is expressed constitutively in both light- and dark-grown tissues. In the transformed cells, transcripts from the pea rbcS gene are processed correctly and translated to yield an authentic pea small subunit polypeptide which is localized in chloroplasts.
Eye Movements During Sleep in Weightlessness
Authors: Quadens O. , Green H.
Published: October 2006

The number of eye movements during sleep increased during the first sleep period in zero gravity but returned to normal by the second night. These rapid-eye-movement functions in flight may be the first variations of an oscillatory system. The ratio of the higher and lower eye movement frequencies oscillates within normal-gravity limits.
Photoejection of Electrons from Flavins in Polar Media
Authors: Getoff N. , Solar S. , McCormick D. B.
Published: October 2006

Riboflavin and 12 of its derivatives have been shown to form solvated electrons under ultraviolet irradiation (253.7 nanometers) in various water-methanol solvent mixtures. The highest quantum yield of solvated electrons (about 0.03) was obtained for flavins containing tyrosine on a side chain in the isoalloxazine N-3 or N-10 position. The splitting of hydrogen atoms from excited flavin molecules was also observed. From the results presented here, it can be determined that the semiquinone transients are formed not only by way of the flavin triplet, as usually suggested, but also by the attack of the electrons and hydrogen atoms on flavin molecules in the ground state. This is important, because the flavin radicals remaining after the electron-ejection or hydrogen-splitting processes must also be considered in the subsequent reaction mechanisms. The electron-ejection process from electronically excited flavins has important implications in the photobiology of these compounds.
Sparing of the Brain in Neonatal Undernutrition: Amino Acid Transport and Incorporation into Brain and Muscle
Authors: Freedman Lewis S. , Samuels Stanley , Fish Irving , Schwartz Stephen A. , Lange Brigitte , Katz Melissa , Morgano Linda
Published: October 2006

Rates of tyrosine and lysine transport and incorporation into protein were measured in control and undernourished weanling rats. Undernutrition was induced by feeding lactating dams a low protein diet (12 percent casein) from birth to day 21. At weaning, body and brain weights of undernourished rats were 50 percent and 88 percent, respectively, of control values. Lysine and tyrosine transport rates into skeletal muscle were reduced by over 75 percent, more than twice the reduction seen in brain. Rates of amino acid incorporation into muscle protein were reduced by approximately 50 percent; the change in rate of incorporation into brain protein was not statistically significant. These data indicate that, in spite of marked retardation of amino acid transport into brain, the brain seems fully capable of maintaining normal rates of protein synthesis.
Prevention of Allograft Rejection by Immunization with Donor Blood Depleted of Ia-Bearing Cells
Authors: Faustman D. , Lacy P. , Davie J. , Hauptfeld V.
Published: October 2006

Strain-specific unresponsiveness was induced in adult mice by immunizing them with donor blood treated with antiserum to Ia (I region-associated antigens) prior to the transplantation of islets of Langerhans. This regimen alone produced greater than 100-day survival of islet allografts transplanted across a major histocompatibility barrier.
Regulation of the Macrophage Content of Neoplasms by Chemoattractants
Authors: Bottazzi Barbara , Polentarutti Nadia , Acero Raffaella , Balsari Andrea , Boraschi Diana , Ghezzi Pietro , Salmona Mario , Mantovani Alberto
Published: October 2006

Factor chemotactic for mononuclear phagocytes was found in supernatant fluids of cultured human and mouse tumor cells. In 11 mouse tumors there was a correlation observed between chemotactic activity and macrophage content of neoplastic tissues. Tumor-derived chemoattractants appear to participate in the regulation of tumor-associated macrophages.
Passive Transfer of Diabetes in the BB/W Rat
Authors: Koevary Steven , Rossini Aldo , Stoller Walter , Chick William , Williams R. Michael
Published: October 2006

Severe diabetes with insulitis was produced in young diabetes-prone BB/W rats by passive transfer of concanavalin A-treated spleen cells from BB/W animals with acute diabetes. Spleen cells alone or in combination with lymph node cells were active in transferring disease.
Effects of Tyrosine Administration on Serum Biopterin in Normal Controls and Patients with Parkinson's Disease
Authors: Yamaguchi Tokio , Nagatsu Toshiharu , Sugimoto Takashi , Matsuura Sadao , Kondo Tomoyoshi , Iizuka Reiji , Narabayashi Hirotaro
Published: October 2006

After administration of tyrosine, total concentration of biopterin, the cofactor for tyrosine hydroxylase, was increased in the striatum, adrenal glands, and serum of rats, and in the serum of humans. Serum biopterin is lower in patients with Parkinson's disease than in normal controls. After oral administration of tyrosine, the increase in serum biopterin concentration was smaller in patients with Parkinson's disease (less than twofold) than in healthy controls (three- to sevenfold). These results suggest that tyrosine may have a regulatory role in biopterin biosynthesis and that patients with Parkinson's disease may have some abnormality in the regulation of biopterin biosynthesis.
Trypsin Inhibition by Mouse Serum: Sexual Dimorphism Controlled by Testosterone
Authors: Kueppers Friedrich , Mills Julie
Published: October 2006

The trypsin inhibiting activity in the serum of male mice is substantially greater than that in females. In five strains of mice and two large groups of interstrain hybrids this difference ranged from 14 (in ICR mice) to 55 percent (in DBA mice). Castration of males significantly decreased the serum trypsin inhibiting activity, whereas the administration of testosterone restored the activity to its original level. Administration of testosterone to female mice increased the activity to a level similar to that in males of the same strain. Because almost all the change in inhibiting activity occurred in the electrophoretic α-1 region, α-1-antitrypsin is probably responsible for this effect.
A Cancer-Associated Lactate Dehydrogenase Is Expressed in Normal Retina
Authors: Saavedra Raul A. , Anderson Garth R.
Published: October 2006

An unusual isozyme of lactate dehydrogenase, lactate dehydrogenase k, is found in high concentrations in cultured cells transformed by the Kirsten murine sarcoma virus and in many human cancer tissues. In experiments described here high levels of a lactate dehydrogenase k activity were detected in extracts of normal rodent retina. This activity had the same key properties as the human tumor isozyme, namely, a highly cathodic electrophoretic mobility and inhibition of enzymatic activity by oxygen and 5′,5′-dipurinenucleoside tetraphosphates. Expression of this activity in the retina may be related to the high aerobic glycolysis characteristic of the retina, a metabolic feature shared with many tumors.
Funding More NIH Research Grants
Authors: Mandel H. George
Published: October 2006

Because of the prospect of a serious decline in the nation's biomedical research capacity owing to diminished federal appropriations, temporary measures should be initiated promptly by the National Institutes of Health to preserve the stability of resources and diversity of research required for future productivity. It is recommended that the available funds be distributed in such a way as to permit some support for 50 percent of competing grant applications approved by the National Institutes of Health study sections. Measures proposed for consideration are a sliding scale for funding, a greater across-the-board reduction, a limit on support for an individual laboratory, and a review of indirect costs.
Endogenous Inhibitors of Monoamine Oxidase Present in Human Cerebrospinal Fluid
Authors: Becker Robert E. , Giambalvo Cecilia , Fox Robert A. , Macho Michael
Published: October 2006

Inhibitory activity against the enzyme monoamine oxidase is present in low molecular weight fractions (less than 100,000) of human cerebrospinal fluid. These endogenous substances of different molecular weights (3000 to more than 35,000) act like monoamine oxidase inhibitor drugs to inhibit both type A and type B monoamine oxidase.
5-hydroxytryptophan Elevates Serum Melatonin
Authors: Namboodiri M. A. A. , Sugden D. , Klein D. C. , Mefford I. N.
Published: October 2006

Daytime administration of 5-hydroxytryptophan to sheep elevated serum melatonin more than sevenfold within 2 hours. This suggests that administration of 5-hydroxytryptophan could be used as the basis of a clinical test of pineal function and that melatonin might mediate some clinical effects of 5-hydroxytryptophan.
Free-Metal Ion Depletion by "Good's" Buffers
Authors: Nakon Robert , Krishnamoorthy C. R.
Published: October 2006

Metal-ion affinity (formation) constants were determined for two "Good's" buffers,
N
-tris(hydroxymethyl)methyl-2-aminoethanesulfonic acid (TES) and
N
,
N
-bis(2-hydroxyethyl)glycine (bicine). The metal chelates formed undergo loss of an internal ligand (alcohol) proton (bicine) and undergo hydrolysis (bicine and TES) and dimerization reactions (TES). Bicine and TES buffer not only hydrogen ions but also metal ions. The metal complexes of "Good's" buffers also buffer hydrogen ions by secondary reactions. The consequences of these reactions are considered in relation to biomedical research.
An Inverted Repeat Borders a Fivefold Amplification in Satellite DNA
Authors: Bonnewell Veta , Fowler Richard F , Skinner Dorothy M.
Published: October 2006

One variant of a complex satellite DNA of the Bermuda land crab is significantly longer than the average repeat unit of the satellite. The extra DNA in the variant is accounted for by a fivefold tandem amplification of a 0.142-kilobase sequence. The amplified sequence is bounded by a tetranucleotide inverted repeat; the upstream arm of the inverted repeat is missing from two other variants of the satellite. The latter variants contain only one copy of a sequence that is closely related to the amplified sequence. By contrast, in several satellite DNA's of other organisms, extra DNA is inserted.
Human Macrophages Armed with Murine Immunoglobulin G2a Antibodies to Tumors Destroy Human Cancer Cells
Authors: Steplewski Zenon , Lubeck Michael D. , Koprowski Hilary
Published: October 2006

Macrophages isolated from tumor-bearing patients as well as cultured human monocytes express Fc receptors that cross-react strongly with murine immunoglobulins of the G2a but only slightly or not at all with the G1, G2b, or G3 subclasses. Such macrophages in the presence of murine immunoglobulin G2a monoclonal antibodies to tumors mediated the killing of tumor cells in vitro. These data suggest that monoclonal antibodies of the G2a subclass may be useful in the immunotherapy of human cancer.
Morphine Tolerance in Genetically Selected Rats Induced by Chronically Elevated Saccharin Intake
Authors: Lieblich Israel , Cohen Edna , Ganchrow Judith R. , Blass Elliott M. , Bergmann Felix
Published: October 2006

Rats of line LC2-Hi that drank about 50 milliliters of a highly palatable saccharine solution daily for 28 consecutive days did not show morphine analgesia or an opioid form of stress-induced analgesia and were not responsive to naloxone. These findings support the idea that chronically elevated saccharine intake may cause increased release and utilization of endogenous opiates.
Circumventing the Blood-Brain Barrier with Autonomic Ganglion Transplants
Authors: Rosenstein Jeffrey M. , Brightman Milton W.
Published: October 2006

Superior cervical ganglia, whose vessels are fenestrated and permeable to protein tracers such as horseradish peroxidase, were transplanted to undamaged surfaces in the fourth ventricle of rat pup brains. Horseradish peroxidase, infused systemically into the host, was exuded from the graft's vessels into the graft's extracellular stroma within 1 minute. At later times the glycoprotein reached the extracellular clefts of adjacent brain tissue, the vessels of which appeared to retain their impermeability. The blood-brain barrier to horseradish peroxide was thus bypassed where the extracellular compartments of graft and brain became confluent. The graft of autonomic ganglia can serve as a portal through which peptides, hormones, and immunoglobulins may likewise enter the brain.
Multiclonal Origin of Polyps in Gardner Syndrome
Authors: Hsu Susan H. , Luk Gordon D. , Krush Anne J. , Hamilton Stanley R. , Hoover Herbet H.
Published: October 2006

Electrophoretic analysis of glucose-6-phosphate dehydrogenase was performed on polyp tissue from three black female patients with Gardner syndrome and who are heterozygous for the A and B forms of this enzyme. Polyp tissues from the three patients displayed the AB phenotype. This finding suggests a multiclonal origin of polyps in Gardner syndrome. Studies of tumors originating from such polyps may provide information about the sequence of cellular events leading to malignant transformation.
Opiate Antagonists Improve Spatial Memory
Authors: Gallagher Michela , King Richard A. , Young Nancy B.
Published: October 2006

Rats trained on an eight-arm radial maze were challenged by placing the maze in new spatial environments. Administration of opiate antagonists, either naloxone or diprenorphine, after exposure to the new environments significantly improved subsequent performance. The effect of naloxone on spatial memory was attenuated when drug administration occurred 2 hours after maze exposure.
Role of the Spleen in the Growth of a Murine B Cell Leukemia
Authors: Kotzin Brian L. , Strober Samuel
Published: October 2006

A spontaneous B cell leukemia (BCL
1
) grew progressively in normal BALB/c mice after injection of tumor cells but did not grow in splenectomized recipients. Despite the absence of progressive tumor growth, residual tumor cells with malignant potential were found in the peripheral blood of the splenectomized animals. Splenectomy performed after injection of tumor cells but before the development of marked leukocytosis also prevented progressive tumor growth and death of the host. Thus the spleen appears to be necessary for progressive proliferation of this lymphocytic leukemia early after passage in vivo.
Developmental Potential of Somatic Nuclei Transplanted into Meiotic Oocytes of
Rana pipiens
Authors: Hoffner Nancy J. , DiBerardino Marie A.
Published: October 2006

Somatic nuclei, when transplanted into oocytes at the stage of first meiotic metaphase, were induced to undergo chromosome condensation and alignment on spindles. When the oocytes completed maturity in vitro and were activated, the somatic nuclei transformed into "fertilization" nuclei and promoted development through embryogenesis. Thus somatic nuclei can reversibly respond to cytoplasms directing either meiotic or mitotic events, and somatic nuclei from differentiated cells may be reversed by conditioning in oocytes.
Placental Luteinizing Hormone-Releasing Factor and Its Synthesis
Authors: Khodr G. S. , Siler-Khodr T. M.
Published: October 2006

The synthesis of a placental luteinizing hormone-releasing factor (pLRF), which is immunologically, physiochemically, and biologically indistinguishable from synthetic LRF, was demonstrated. The incorporation of
3
H-labeled leucine by human placental tissue in vitro into pLRF was determined by purification on carboxymethyl-cellulose and specific immunoprecipitation of the
3
H-labeled pLRF. The specific activity of the pLRF released into the medium increased 100-fold from day 1 to day 2 of culture and attained a concentration of 2.84 microcuries per microgram. These data indicate that the pLRF that was released initially was endogenous, whereas that released subsequently reflected synthesis.
Choline Acetyltransferase-Containing Neurons in Rodent Brain Demonstrated by Immunohistochemistry
Authors: Kimura Hiroshi , McGeer Patrick L. , Peng Frank , McGeer Edith G.
Published: October 2006

Choline acetyltransferase was demonstrated in neuronal structures of the rodent central nervous system by immunohistochemistry through the application of Fab fragments obtained from monospecific antiserums to human choline acetyltransferase. The specificity of the antiserum for the enzyme was confirmed by the staining of both the ventral horn motor neurons in the rat spinal cord and the neuromuscular junction of the guinea pig diaphragm. Enzyme-containing cell bodies were observed in frontal sections of rat and guinea pig brain in the neostriatum, accumbens, nucleus of the diagonal band, medial septum, and olfactory tubercle. Positively staining fibers and probable nerve terminals were also found in the olfactory tubercle field and other areas of the basal forebrain. The results provide information on the distribution of the cholinergic systems in the rostral forebrain of the rodent.
Apparatus for the Determination of Carbon Dioxide in the Respiration of Apples
Authors: Harding P. L. , Maney T. J. , Plagge H. H.
Published: October 2006

A respiration chamber of low original cost was used, which because of its large size was adapted to handling samples of considerable bulk or quantity. The most important feature of the chamber was its wide mouth, which permitted easy insertion and removal of samples.

With the double system of connections, either total or intermittent determinations were made with only momentary stoppage of the air-stream.

The flow-meter proved very satisfactory in maintaining a known and uniform rate of aeration.

The apparatus described was admirably adapted to the determination of carbon dioxide as a measure of respiration on apples, tomatoes and cut flowers.
Cellular Transplantation in the Treatment of Experimental Hepatic Failure
Authors: Makowka L. , Falk R. E. , Rotstein L. E. , Falk J. A. , Nossal N. , Langer B. , Blendis L. M. , Phillips M. J.
Published: October 2006

The survival of Lewis rats with D-galactosamine-induced fulminant hepatic failure was prolonged if they were given intraperitoneal injections of single-cell suspensions of liver or bone marrow cells from normal rats. Suspensions of liver cells were also effective in prolonging the survival of rats with ischemia-induced hepatic necrosis. The liver cells did not act by repopulating the recipient liver.
Clocked Cell Cycle Clocks
Authors: Edmunds Leland N. , Adams Kenneth J.
Published: October 2006

The cell division cycle of both mammalian cells and microorganisms, which apparently has both deterministic and probabilistic features, is a clock of sorts in that the sequence of events that comprise it measures time under a given set of environmental conditions. The cell division cycle may itself be regulated by a programmable clock that, under certain conditions, can generate circadian periodicities by interaction with a circadian pacemaker. These clocks must insert time segments into the cell division cycle in order to generate the observed variability in cellular generation times.
Suppressible Four-Base Glycine and Proline Codons in Yeast
Authors: Donahue Thomas F. , Farabaugh Philip J. , Fink Gerald R.
Published: October 2006

Five ICR-170—induced mutations at the
His
4 locus in yeast are +1 G⋅C (G, guanine; C, cytosine) additions in DNA regions that contain multiple G⋅C base pairs. These mutations represent both nonsuppressible and suppressible alleles. All externally, suppressible frameshift mutations occur in glycine and proline codons to produce the four-base codons GGGU (U, uracil), GGGG, and CCCU. This implies that suppression of these four-base codons in yeast, as in bacteria, involves a four-base anticodon or its functional equivalent. Two identical four-base codons (CCCU) at widely separate regions within
His
4 are not suppressed equally.
Dentition of Chilean Paleo-Indians and Peopling of the Americas
Authors: Turner C. G. , Bird J.
Published: October 2006

Teeth of 12 cremated paleo-Indians (11,000 years old) from caves in southern Chile have crown and root morphology like that of recent American Indians and north Asians, but unlike that of Europeans. This finding supports the view that American Indians originated in northeast Asia. This dental series also suggests that paleo-Indians could easily have been ancestral to most living Indians, that very little dental evolution has occurred, and that the founding paleo-Indian population was small, genetically homogeneous, and arrived late in the Pleistocene.
Pineal
N
-Acetyltransferase Is Inactivated by Disulfide-Containing Peptides: Insulin Is the Most Potent
Authors: Namboodiri M. A. A. , Favilla J. T. , Klein D. C.
Published: October 2006

Pineal
N
-acetyltransferase can be inactivated in broken cell preparations by cystamine through a mechanism of thiol-disulfide exchange. Some, but not all, disulfide-containing peptides can inactivate this enzyme; the most potent inactivator is insulin. These findings suggest that a disulfide-containing peptide with high reactivity toward
N
-acetyltransferase may participate in the intracellular regulation of this enzyme.
Frontiers of the Biological Sciences
Authors: Davis Bernard D.
Published: October 2006

The history of the molecular revolution in biology is described, emphasizing its dependence on the emergence of bacterial genetics, the fusion of genetics and biochemistry, and the development of greatly improved techniques for studying macromolecules. Central concepts have included molecular information transfer, both by nucleic acids and by allosteric proteins; the spontaneous conversion of one-dimensional information into three-dimensional structures; and the extraordinary unity in the molecular mechanisms underlying the rich diversity of biology. The merging of molecular and morphological studies, to yield the very broad field of cell biology, is described more briefly, as are also some present frontiers in several areas of biology that present challenges at other levels of organization.
Origin of the Cholecystokinin-Containing Fibers in the Rat Caudatoputamen
Authors: Meyer D. K. , Beinfeld M. C. , Oertel W. H. , Brownstein M. J.
Published: October 2006

Large amounts of cholecystokinin-octapeptide (CCK) are present in the rat caudatoputamen. The peptide occurs in axons and nerve endings but not in perikarya. The origin of CCK in the caudatoputamen was investigated with the use of immunocytochemistry and a radioimmunoassay specific for CCK. Although a small amount of CCK (approximately 30 percent) originates in the amygdaloid complex, the bulk of the peptide (approximately 70 percent) occurs in processes of neurons located ventral to the caudatoputamen, that is, the claustrum or the piriform cortex. The claustrum and piriform cortex receive inputs from various cortical areas and the olfactory system, respectively, and may process information and relay it to the caudatoputamen. Thus CCK may be the transmitter in the final common pathway linking various cortical areas and the olfactory system to the caudatoputamen.
Computing in Documentation and Scholarly Research
Authors: Haas Warren J.
Published: October 2006

Production, organization, and delivery of publications of all types and in all formats are being transformed by computer and communications technology. The system of scholarly communication is, as a result, undergoing fundamental change. Whether that change will be seen as unqualified improvement depends on the way organizational and economic issues are resolved.
Influence of Cholesterol on Water Penetration into Bilayers
Authors: Simon Sidney A. , McIntosh Thomas J. , Latorre Ramon
Published: October 2006

X-ray diffraction and capacitance measurements have been used to calculate the depth to which water penetrates in fully hydrated bacterial phosphatidylethanolamine bilayers in the presence and absence of cholesterol. The data indicate that cholesterol decreases the depth of water penetration by about 2.5 angstroms.
Legal Abortion: The Public Health Record
Authors: Cates Willard
Published: October 2006

The increasing availability and utilization of legal abortion in the United States had several important effects on public health in the 1970's. It reduced deaths and surgical complications among women of childbearing age; it made possible the development of safer surgical procedures for pregnancy termination; and it increased the provision of low-cost outpatient gynecologic services. There is some concern about potential adverse outcomes in future desired pregnancies and possibly higher risks of breast cancer in certain women.
Penicillin Target Enzyme and the Antibiotic Binding Site
Authors: Kelly Judith A. , Moews Paul C. , Knox James R. , Frère Jean-Marie , Ghuysen Jean-Marie
Published: October 2006

The three-dimensional structure of a penicillin-sensitive D-alanyl-carboxypeptidase-transpeptidase has been determined by x-ray crystallography to a resolution of 2.8 angstroms. The site of binding of the β-lactam antibiotics penicillin and cephalosporin has been located. These findings constitute direct observation of the interaction of β-lactams with a transpeptidase enzyme and establish the feasibility of defining the molecular stereochemistry of this interaction for purposes of drug design.
(+)-Amphetamine Binding to Rat Hypothalamus: Relation to Anorexic Potency for Phenylethylamines
Authors: Paul Steven M. , Hulihan-Giblin Bridget , Skolnick Phil
Published: October 2006

Saturable and stereospecific binding sites for (+)-[
3
H]amphetamine were demonstrated in membrane preparations from rat brain. The density of these binding sites varies among brain regions and is highest in the hypothalamus and brainstem. Specific (+)-[
3
H]amphetamine binding in hypothalamus is largely confined to synaptosomal membranes, rapidly reversible, and sensitive to both heat and proteolytic enzymes. Scatchard analysis of the equilibrium binding data revealed two distinct sites with apparent affinity constants of 93 and 300 nanomoles per liter, respectively. The effects of various psychotropic drugs as well as a number of putative neurotransmitters and related agonists and antagonists in displacing specific (+)-[
3
H]amphetamine binding demonstrate that these binding sites are not associated with any previously described neurotransmitter or drug receptors, but are specific for amphetamine and related phenylethylamine derivatives. Furthermore, the relative affinities of a series of phenylethylamine derivates for (+)-[
3
H]amphetamine binding sites in hypothalamic membranes is highly correlated to their potencies as anorexic agents. These results suggest the presence of specific receptor sites in hypothalamus that mediate the anorexic activity of amphetamine and related drugs.
Sensitivity to Carcinogenesis in Nude Mice: Skin Tumors Caused by Transplacental Exposure to Ethylnitrosourea
Authors: Anderson Lucy M. , Last-Barney Kathleen , Budinger John M.
Published: October 2006

Female athymic nude mice and their phenotypically normal littermates were exposed transplacentally to ethylnitrosourea. Skin tumors (papillomas and sebaceous adenomas) developed on the nude mice with an almost tenfold greater incidence than on their haired littermates. Skin tumors were also induced on nude mice but not haired controls by direct intraperitoneal treatment with ethylnitrosourea. These results indicate that nude mice have higher than normal susceptibility to carcinogenesis under some circumstances.
Mammalian Muscle Acetylcholine Receptor: A Supramolecular Structure Formed by Four Related Proteins
Authors: Conti-Tronconi Bianca M. , Gotti Cecilia M. , Hunkapiller Michael W. , Raftery Michael A.
Published: October 2006

The nicotinic acetylcholine receptor has been purified from fetal calf muscle. Amino terminal amino acid sequence data indicate that the mammalian receptor is formed from closely related but distinct subunits. A cytoskeletal component, actin, may be associated with the receptor.
Prolonged Inhibition in Burst Firing Neurons: Synaptic Inactivation of the Slow Regenerative Inward Current
Authors: Wilson Wilkie A. , Wachtel Howard
Published: October 2006

By using voltage clamping and microiontophoretic techniques, it has been found that the prolonged cholinergic and dopaminergic inhibition seen in
Aplysia
burst firing neurons occludes the inward current on which slow oscillations depend. It also mimics the temperature and ionic sensitivity of that inward current. This prolonged inhibition, which cannot be inverted and is insensitive to extracellular potassium changes, thus appears to result from a synaptically produced inactivation of the regenerative slow inward current underlying bursting.
Tumor Cell Killing by Phorbol Ester—Differentiated Human Leukemia Cells
Authors: Weinberg J. Brice
Published: October 2006

The tumor promoter 12-
O
-tetradecanoyl-phorbol-13-acetate causes differentiation of cells of the human leukemia cell line HL60 to nondividing macrophage-like cells. These differentiated cells are cytotoxic for tumor cells (including parent, untreated HL60 cells) in vitro. Agents that induce this desirable differentiation to nondividing, antitumor effector cells may be useful in the experimental treatment of leukemia.
Biosynthesis and Processing of a Human Precursor Complement Protein, pro-C3, in a Hepatoma-Derived Cell Line
Authors: Morris Katherine M. , Goldberger Gabriel , Colten Harvey R. , Aden David P. , Knowles Barbara B.
Published: October 2006

A 180,000-dalton single-chain molecule (human pro-C3) is the precursor of the third component of human complement (C3), a disulfide-linked two-chain protein. The pro-C3 is converted by limited proteolysis to C3. The relationship between pro-C3 and C3 was established with the use of Hep G2, a cell line derived from a human hepatocellular carcinoma, which synthesizes at least 17 plasma proteins.
Tumor Imaging with Radioactive Metal Chelates Conjugated to Monoclonal Antibodies
Authors: Scheinberg David A. , Strand Mette , Gansow Otto A.
Published: October 2006

High-resolution gamma camera images of mouse erythroid tumors were obtained by use of leukemia cell-specific monoclonal antibodies labeled with bifunctional radioactive metal chelates. Small tumors (200 to 300 milligrams) were visible without subtraction or enhancement 1 to 5 hours after injection of antibody. Chelate-derivitized monoclonal antibodies permit targeting of a broad spectrum of radioisotopes, including those that are optimum for gamma camera imaging or positron tomography, as well as those that are tumoricidal.
Oxytocin, Vasopressin, and Estrogen-Stimulated Neurophysin: Daily Patterns of Concentration in Cerebrospinal Fluid
Authors: Perlow M. J. , Reppert S. M. , Artman H. A. , Fisher D. A. , Self S. M. , Robinson A. G.
Published: October 2006

The concentrations of oxytocin, arginine vasopressin, and estrogen-stimulated neurophysin in cerebrospinal fluid of monkeys showed a daily fluctuation with high concentrations occurring during the light period. The patterns of oxytocin and estrogen-stimulated neurophysin in the cerebrospinal fluid were not observed in the plasma nor were they altered after the administration of a dose of estradiol that increased concentrations of estrogen-stimulated neurophysin in plasma. The disassociation between these cerebrospinal fluid and plasma patterns and values suggests that the secretory activity of neurons that release estrogen-stimulated neurophysin and oxytocin into the cerebrospinal fluid is controlled by mechanisms different from those that control their release into the plasma.
Oxalate Degradation by Microbes of the Large Bowel of Herbivores: The Effect of Dietary Oxalate
Authors: Allison Milton J. , Cook Herbert M.
Published: October 2006

Rates of oxalate degradation by microbes in gastrointestinal contents from rabbits, guinea pigs, swine, and a horse increased after addition of oxalate to diets. A similar response was previously observed with ruminal microbes from cattle and sheep. Bacteria that utilize oxalate for growth appear to be selected by increased levels of dietary oxalate.
Cultivation in Vitro of the Vivax-Type Malaria Parasite
Plasmodium cynomolgi
Authors: Nguyen-Dinh Phuc , Gardner Amy L. , Campbell Carlos C. , Skinner Jimmie C. , Collins William E.
Published: October 2006

The vivax-type simian malaria parasite Plasmodium cynomologi was cultured in vitro by both the candle jar method and the continuous flow technique, with rhesus monkey erythrocytes and RPMI 1640 medium supplemented with Hepes buffer and human serum. After 6 weeks in culture, the growth of the parasite had permitted a 5 × 10
6
cumulative dilution of the original inoculum. Cultured parasites remained infective to rhesus monkeys and exhibited a reversible decrease in the ameboid behavior of their trophozoites.