Showing papers by "University of Colorado Boulder published in 1970"
TL;DR: A technique for growing human bone marrow cell colonies in agar-gel medium is described in this paper, where feeder layers containing 1 × 106 normal human peripheral white blood cells are used as the stimulus for colony growth.
Abstract: A technique for growing human bone marrow cell colonies in agar-gel medium is described. “Feeder layers” containing 1 × 106 normal human peripheral white blood cells are used as the stimulus for colony growth. Human bone marrow aspirates are collected in heparinized syringes and plated as 2 × 105 cells on “feeder layers.” Normal human bone marrow yields 32–102 colonies per 2 × 105 cells plated. Colonies are almost exclusively granulocytic. Growth rate of colonies is slower than with mouse bone marrow but colonies reach a comparable size (500–1500 cells) at days 12–16.
1,286 citations
TL;DR: DNA synthesis and mitosis are inducible in multinucleate HeLa cells formed by fusion between cells in different phases of the life cycle.
Abstract: DNA synthesis and mitosis are inducible in multinucleate HeLa cells formed by fusion between cells in different phases of the life cycle.
737 citations
TL;DR: Further evidence is put forward for the inducibility of chromosome condensation, particularly its consequences in interphase cells that are not ready for mitosis.
Abstract: Further evidence is put forward for the inducibility of chromosome condensation, particularly its consequences in interphase cells that are not ready for mitosis.
703 citations
01 Jan 1970
453 citations
TL;DR: In this paper, a technique for producing deep muscle relaxation by means of an information feedback technique is described, where the subject hears a tone with a frequency proportional to the EMG level of the muscle being monitored.
316 citations
TL;DR: In this article, the solar corona was photographed at an effective wavelength of 6500 A with an f/16, 11.1 cm aperture camera during the eclipse of 12 November 1966.
Abstract: During the eclipse of 12 November 1966, the solar corona was photographed at an effective wavelength of 6500 A with an f/16, 11.1 cm aperture camera. Reduction of the observations yields coronal radiances and polarizations from 1.4 to 3.5 solar radii. Standard techniques are used for the separation of F and K-coronas, determination of coronal electron densities and temperatures, and estimation of the orientation of the major streamers in space.
313 citations
TL;DR: In this paper, electrical conductivity without particle-particle or waveparticle collisional noise or radiation was shown to be achievable without particle particle particle or wave particle collimation.
207 citations
TL;DR: Messenger RNA synthesis and release by vaccinia subviral particles (cores) was studied in vitro using in part a nitrocellulose filter binding assay for the detection of core-bound, nascent messenger RNA.
161 citations
TL;DR: Analysis of variables relating to pre-hospital behavior and post-hospital adjustment indicates that the distinguishing characteristics of suicide attempters are fewer than might be expected from the literature.
Abstract: This paper reports a controlled, long-term followup study of adolescent suicide attempters, using as controls carefully matched youngsters hospitalized for psychiatric illness. Analysis of variables relating to pre-hospital behavior and post-hospital adjustment indicates that the distinguishing characteristics of suicide attempters are fewer than might be expected from the literature.
155 citations
TL;DR: Methods are discussed whereby this fraction of the newborn population might be detected and possibly reduced and how this fraction may be reduced.
Abstract: The incidence of gross chromosomal abnormality was measured in a large (4500), relatively unbiased sample of New Haven infants born during 1 year. The frequency of infants with abnormal chromosomal constitutions was 0.5 percent. For mothers over age 34, 1.5 percent of newborns were chromosomally abnormal. Only one in four of these infants could have been detected by phenotypic criteria alone. Methods are discussed whereby this fraction of the newborn population might be detected and possibly reduced.
154 citations
TL;DR: The kinetics suggest that the breakdown of IRS(ile-AMP) upon exposure of the complex to tRNA Ile is not a result of failure of a normal step in the aminoacyl transfer reaction sequence.
TL;DR: It has been demonstrated by chromatographic analysis that, following intraperitoneal ethanol injection, acetaldehyde accumulates in the blood of DBA/2J mice to a greater extent than it does in C57BL/6J mice, lending support to the possibility that the lower aldehyde dehydrogenase activity of the DBA or 2J mice results in an acetaldehyde-induced avoidance of ethanol.
TL;DR: Vaccinia virus cores catalyze the incorporation of ATP into polyriboadenylic acid sequences of approximately 150 nucleotides in length, and evidence is presented for a covalent association between the poly A sequences and the regular viral RNA moiety.
TL;DR: The presence of a nonspecific NADPH-linked aldehyde reductase (alcohol:NADP oxidoreductase, EC 1.1.2) was observed in various areas of bovine brain in vitro and was found that the enzyme was localized primarily in the soluble supernatant fraction of rat brain homogenates.
TL;DR: It is suggested that the "wall-modifying enzyme" may be responsible for the limited polygalacturonic acid-degrading activity present in the purified preparation, which is unable to degrade a wide variety of polysaccharide, glycoside, and peptide substrates.
Abstract: A study of the degradation of plant cell walls by the mixture of enzymes present in Pectinol R-10 is described. A "wall-modifying enzyme" has been purified from this mixture by a combination of diethylaminoethyl cellulose, Bio Gel P-100, and carboxymethyl cellulose chromatography. Treatment of cell walls with the "wall-modifying enzyme" is shown to be a necessary prerequisite to wall degradation catalyzed by a mixture of polysaccharide-degrading enzymes prepared from Pectinol R-10 or by an alpha-galactosidase secreted by the pathogenic fungus Colletotrichum lindemuthianum. The action of the "wall-modifying enzyme" on cell walls is shown to result in both a release of water-soluble, 70% ethanol-insoluble polymers and an alteration of the residual cell wall. A purified preparation of the "wall-modifying enzyme" is unable to degrade a wide variety of polysaccharide, glycoside, and peptide substrates. However, the purified preparation of wall-modifying enzyme has a limited ability to degrade polygalacturonic acid. The fact that polygalacturonic acid inhibits the ability of the "wall-modifying enzyme" to affect cell walls suggests that the "wall-modifying enzyme" may be responsible for the limited polygalacturonic acid-degrading activity present in the purified preparation. The importance of a wall-modifying enzyme in developmental processes and in pathogenesis is discussed.
TL;DR: It is anticipated that with more complete and longer follow-up the incidence of complete heart block will be even higher, as patients with right bundle-branch block and either left superior or left inferior intraventricular block have evidence of coronary artery disease or hypertension.
Abstract: In an 11-year period 209 cases of partial bilateral bundle-branch block were seen. These included patients with right bundle-branch block and either left superior or left inferior intraventricular block. The majority of patients had evidence of coronary artery disease or hypertension, though a significant number had no clinical evidence of heart disease. The majority of patients had follow-up ECG tracings, with an average follow-up for the whole group of about 2 years. The incidence of complete heart block was 14.4% (30 of 209). Complete heart block developed more than 10 years after the discovery of bilateral bundle-branch block in several patients. It is anticipated that with more complete and longer follow-up the incidence of complete heart block will be even higher.
TL;DR: Linkage relationships between human genes have been determined by following chromosome losses from human–Chinese hamster hybrid cells.
Abstract: Genetics of Somatic Mammalian Cells: Linkage Studies with Human–Chinese Hamster Cell Hybrids
TL;DR: The phenomenon of premature chromosome condensation is induced in unstimulated horse lymphocytes, bovine spermatozoa, Chinese hamster ovary cells, embryonic chick fibroblasts and erythrocytes, Xenopus kidney and mosquito cells by fusing each of these cell types with HeLa cells blocked in mitosis.
Abstract: The phenomenon of premature chromosome condensation (PCC) is induced in unstimulated horse lymphocytes, bovine spermatozoa, Chinese hamster ovary cells, embryonic chick fibroblasts and erythrocytes, Xenopus kidney and mosquito cells by fusing each of these cell types with HeLa cells blocked in mitosis. Thus it becomes possible to visualize chromosomes even from non-multiplying cells of heterologous species, such as, chick erythrocytes and bovine spermatozoa.
TL;DR: Clinical and biochemical findings in two brothers each of whom has homocystinuria and methylmalonic aciduria may tentatively be ascribed to a defect in the uptake or early metabolism of B12, the condition most likely being inherited as an autosomal recessive trait.
TL;DR: It is shown that, as medical students move through their training, a certain degree of their innate ability communicate with mothers of ill children seems to have been altered by their desire to obtain factual information which may well limit their effectiveness as the child's physician.
Abstract: The use of videotapes to observe senior medical students as they interviewed mothers of children has demonstrated a deficit in their ability to communicate with these parents. Seniors often fail to obtain the vital information pertaining to the child as an individual within a family unit. This study was performed to test the hypotheses that freshmen would obtain (1) more interpersonal and (2) less factual information from mothers of ill children than would seniors. Randomly selected freshmen and seniors videotaped interviews of three simulators who were programmed to portray mothers of a child with a serious organic illness with related psychosocial problems. The use of the programmed "mother" permitted each student to obtain a standardized interviewing experience. The students were given identical information about these children and informed that the mothers were simulators. Objective measurements were made by five trained observers who rated each videotape using a modified interaction analysis technique and an objective checklist of facts obtained. An interrater reliability coefficient for each group of ratings was high, rarely falling below 0.80. The results clearly demonstrated that freshmen obtained significantly more interpersonal information (i.e., the affect of the illness upon the child and his family) and asked fewer leading questions than did seniors (p
TL;DR: In vitro mixing experiments suggested that the impaired ADP platelet aggregation was due neither to the presence of plasma ADP inhibitors, a refractory state due to increased circulating levels of ADP, anticoagulants, nor to a selected population of platelets.
Abstract: Extract: Studies of platelet function were performed on venous blood specimens from 64 newborn infants within 0–48 h after birth. Fifty-two of the infants studied were normal, full-term average for gesta-tional age (AGA) infants, three were normal, premature AGA infants, seven were premature AGA infants with the respiratory distress syndrome (RDS), and two were premature AGA infants who had repeated apneic periods. Although it was not possible to study all variables of platelet function in each of the groups, those studies that were performed showed no differences in the results based on the group to which an individual infant belonged. Compared with 24 normal adult controls, the infants showed impaired platelet aggregation in the presence of ADP, collagen, and thrombin. The mean time required for maximal platelet aggregation with ADP, collagen, and thrombin for the adults was 120, 230, and 74 sec, respectively, compared with values of 160, 443, and 158 sec for the infants (table II, figs. 2, 3, and 4). The percentage total platelet aggregation with ADP, collagen, and thrombin for the adults was 79, 91, and 74% compared with 47, 73, and 47%, respectively, for the infants (table II, figs. 2, 3, and 4). Infant whole blood and platelet-rich plasma clot retraction were markedly defective compared with normal adults (table I). In addition, platelet factor 3 release in 10 normal infants, as measured by the modified Stypven time, was decreased when compared with 10 values for normal adults (fig.5). Other variables of platelet function (bleeding times, native blood platelet adhesiveness, petechiometer tests) studied in newborn infants were normal (table I). Thrombelastograms were compatible with hypercoagulability of the blood (table I). None of the infants studied had clinical evidence of a bleeding tendency. In vitro mixing experiments suggested that the impaired ADP platelet aggregation was due neither to the presence of plasma ADP inhibitors, a refractory state due to increased circulating levels of ADP, anticoagulants, nor to a selected population of platelets. Physiologic alterations of infant platelets are similar to platelet functional changes observed in thrombasthenia. Speculation: Transient physiologic alterations have been described in many components of the newborn's blood, i.e., decreased plasma coagulation factors, red cell enzyme changes, low immunoglobulins, and an altered kinin system. It is not surprising, therefore, to find a transient platelet functional deficiency as well. Indeed, this hypofunction may be a defense against intravascular coagulation at a time when the infant's blood may be hypercoagulable and susceptible to increased thrombotic tendencies. Whether this platelet functional alteration could aggravate or be related to the cause of hemorrhage in severely ill infants remains to be shown.
TL;DR: In this article, a tunable dye laser has been used to measure the fine-structure splitting of the state of a crossed-beam photodetachment experiment in order to determine electron affinity.
Abstract: A tunable dye laser has been used to measure the fine-structure splitting of the $^{2}P$ state of ${\mathrm{S}}^{\ensuremath{-}}$ in a crossed-beam photodetachment experiment. These measurements verify photodetachment threshold laws and provide the most accurate experimental determination of any electron affinity.
TL;DR: It is concluded that platelet abnormalities regularly occur in patients with prosthetic mitral valves and may contribute to thromboembolism in this group and therapy with 800 mg of sulfinpyrazone per day corrects demonstrated abnormalities and may be useful for prevention of thrombectomy in patientsWith prostheticMitral valves.
Abstract: Platelet survival time and platelet adhesiveness and aggregation were examined in 16 patients with prosthetic mitral valves. Subsequently, nine patients were treated with sulfinpyrazone in doses of 400 mg and 800 mg/day, and the studies were repeated after a treatment period of 5 to 8 weeks. 51 Chromium survival time was shortened in 15 of 16 patients, and the mean value for the entire group was 5.49 ± 0.23 days (normal, 6.73 ± 0.21 days; P P P
TL;DR: Abrasion and its relationship to weathering was studied by running fresh and weathered specimens of Colorado River granitic gravel in a Kuenen-type abrasion tank at the University of Texas.
Abstract: Precambnan outcrops in the Llano Uplift of central Texas furnish the Colorado River with a distinctive granitic load which changes systematically as it moves downstream. In 160 miles between Austin and the Columbus-Eagle Lake area, coarse granitic gravel diminishes in size by about 50 percent and changes from a dommantly granite-gneissaplite assemblage to a dominantly pegmatite-graphic granite assemblage. Coarse quartz and chert gravel diminish in size by about 30 percent and 20 percent, respectively. In this reach, the Colorado flows on a flood plain whose alluvial width and depth stay fairly constant, a situation unfavorable for significant down-valley sorting (Mackin, 1963). Field observations generally lead to the same conclusion.
Abrasion and its relationship to weathering was studied by running fresh and weathered specimens of Colorado River granitic gravel in a Kuenen-type abrasion tank at the University of Texas. Degree of weathering was slight to moderate, with biotite and feldspar the primary and secondary targets. Abrasion of fresh granitic gravel during 160 miles of travel produced only a 10 percent reduction in size. Abrasion of weathered gravel produced a reduction of more than 50 percent and was clearly related to lithology; the biotite-bearing rocks (granite, gneiss, and some aplite) were the least durable, the biotite-free rocks (pegmatite and graphic granite) most durable. Abrasion of quartz and chert produced a reduction in size of less than 10 percent.
Changes in size and lithology of coarse granitic gravel along the lower Colorado River are best explained by abrasion of particles tha t weather slightly during periods of temporary alluvial storage. Reduction in size of quartz and chert are not satisfactorily explained for the reach between Austin and Columbus-Eagle Lake, but downstream from Eagle Lake, sorting appears to be in control.
TL;DR: Change in activity as a function of selection during the last five generations was found to be somewhat less than that during the first five generations, although the correlated response in open-field defecation has continued.
Abstract: The response to selection for open-field activity in each of six lines of mice (two selected for high activity, two selected for low activity and two controls) is presented. Change in activity as a function of selection during the last five generations was found to be somewhat less than that during the first five generations, although the correlated response in open-field defecation has continued. The realized heritability of open-field activity was estimated to be 0.13±.02 and the realized genetic correlation between open-field activity and defecation was −0.80±.13. During the tenth generation of selection, second litters were obtained so that full-sibs ofS
10 subjects could be tested in an extensive activity battery and thus assessed for the situational generality of the response to selection. In general, selection for open-field activity has produced lines which differ markedly in both activity and defecation in apparatus which have some elements in common with the open field. Apparatus which result in significant differences between the high-and low-active lines are boxlike and illuminated, but do not necessarily possess the “openness” of the open field. However, significant differences were not observed in more confining apparatus nor in exercise wheels.
TL;DR: In this paper, the authors examined the social effects of a legal reform on the highway death rate using the Interrupted Time-Series research design, a method of analysis that has broad potential use in studies of legal change more generally.
Abstract: The social effects of a legal reform are examined in this paper utilizing the Interrupted Time-Series research design, a method of analysis that has broad potential use in studies of legal change more generally. A previous demonstration of the applicability of this design to the sociology of law concerned the Connecticut crackdown on speeders (see Campbell and Ross, 1968; Glass, 1968). In that study, the substantive findings were that the crackdown had little effect on the highway death rate, and that it introduced certain unexpected and undesirable changes into the legal process in Connecticut. The present study concerns a similar attempt to lower the highway death rate through changes in the law, specifically the British Road Safety Act of 1967. Critical scrutiny of the data indicates that in this instance the legal change quite impressively achieved its goal. The British crackdown attempted to get drunken drivers off the road, and thus took aim at a scientifically demonstrated correlate of automobile accidents. The Connecticut crackdown, in contrast, was based on commonsense considerations unsupported even by correlational studies. Its sponsors claimed success prematurely, before such possibilities as random variation and statistical regression could be ruled out as explanations of an apparently strikii~g decline in accident rate. In the present study, similar claims turned out to be justified.