Showing papers by "University of North Carolina at Chapel Hill published in 1983"

Capillary zone electrophoresis

Abstract: SUMMARY Capillary electrophoresis offers the possibility of rapid and effective separations in an instrumental format. The two most serious obstacles for future development are the present insufficient detector sensitivity and residual adsorption of solutes to the capillary surface. Capillaries offer some advantages over traditional gel systems. Efficient heat dissipation from capillaries permits the application of unusually high voltages which results in fast and efficient separations. On-line sample injection and detection along with the reusable nature of capillaries makes this format suitable for automation. This could be a significant advantage in situations where repetitive analyses must be run. Capillaries lend themselves to collection of accurate physico-chemical data such as mobilities from migration times and diffusion coefficients from zone widths. They are also an ideal system in which to investigate non-aqueous separation media (ref. 14). Forming gels in a variety of non-aqueous solvents might be difficult, and capillaries offer an uncomplicated approach to the problem. Non-aqueous solvents, although not traditional in electrophoresis, offer exciting possibilities. The wider range of acid and base strengths possible in solvents other than water, as well as the ability to solvate very hydrophobic solutes, could greatly expand the range of substances amenable to electrophoretic separation and analysis.

Sexual Politics, Sexual Communities: The Making of a Homosexual Minority in the United States, 1940-1970

Abstract: With thorough documentation of the oppression of homosexuals and biographical sketches of the lesbian and gay heroes who helped the contemporary gay culture to emerge, Sexual Politics, Sexual Communities supplies the definitive analysis of the homophile movement in the U.S. from 1940 to 1970. John D'Emilio's new preface and afterword examine the conditions that shaped the book and the growth of gay and lesbian historical literature. "How many students of American political culture know that during the McCarthy era more people lost their jobs for being alleged homosexuals than for being Communists? ...These facts are part of the heretofore obscure history of homosexuality in America--a history that John D'Emilio thoroughly documents in this important book."--George DeStefano, Nation "John D'Emilio provides homosexual political struggles with something that every movement requires--a sympathetic history rendered in a dispassionate voice."--New York Times Book Review "A milestone in the history of the American gay movement."--Rudy Kikel, Boston Globe

Hostility, CHD incidence, and total mortality: a 25-year follow-up study of 255 physicians.

Abstract: High levels of hostility as assessed by a MMPI scale (Ho) have been found associated with increased levels of arteriographically documented coronary atherosclerosis. In this study we examined the relationship between hostility and subsequent health status in a 25-year follow-up of 255 medical students who completed the MMPI while in medical school. High Ho scores were found to be predictive of both clinical coronary disease incidence and total mortality.

Application of the energy gap law to nonradiative, excited-state decay

Abstract: As predicted by the energy gap law, which can be used to relate excited state, nonradioactive decay rate constants (k/sub nr/) and emission energies (E/sub em/), it is shown that plots of 1nk/sub nr/ vs E/sub em/ are linear for: (1) The metal to ligand charge transfer (MLCT) excited states in the series Re(bpy)(CO)/sub 3/L/sup +/ (bpy is 2,2'-bipyridine; L = PMe/sub 3/, CH/sub 3/CN,...). (2) The d-d excited states in the series Rh(NH/sub 3/)/sub 5/L/sup 3 +/ (L = CH/sub 3/CN, py,...). (3) Solvent effects for ..pi..-..pi..* fluorescence from 6-hydroxy-9-phenyl-fluoron and fluorescein. (4) The dsigma*-sigmap excited states in the dimers Rh/sub 2/(CNR)/sub 4/(AA)/sub 2/ (AA = bis(diphenylphosphino)methane or bis(diphenylarsino)methane. 4 figures, 3 tables.

Bias in Treatment Assignment in Controlled Clinical Trials

Abstract: Controlled clinical trials of the treatment of acute myocardial infarction offer a unique opportunity for the study of the potential influence on outcome of bias in treatment assignment. A group of 145 papers was divided into those in which the randomization process was blinded (57 papers), those in which it may have been unblinded (45 papers), and those in which the controls were selected by a nonrandom process (43 papers). At least one prognostic variable was maldistributed (P less than 0.05) in 14.0 per cent of the blinded-randomization studies, in 26.7 per cent of the unblinded-randomization studies, and in 58.1 per cent of the nonrandomized studies. Differences in case-fatality rates between treatment and control groups (P less than 0.05) were found in 8.8 per cent of the blinded-randomization studies, 24.4 per cent of the unblinded-randomization studies, and 58.1 per cent of the nonrandomized studies. These data emphasize the importance of keeping those who recruit patients for clinical trials from suspecting which treatment will be assigned to the patient under consideration.

A Meta-Analysis of the Correlates of Role Conflict and Ambiguity

Abstract: The correlational literature concerning the relationships of role conflict and ambiguity to numerous hypothesized antecedents and consequences is still somewhat unclear after a decade of research Schmidt-Hunter meta-analysis procedures were applied to the results of 43 past studies in an effort to draw valid conclusions about the magnitude and direction of these relationships in the population For some correlates, apparently inconsistent research results could be ascribed largely to statistical artifacts. For other correlates, it seems that moderator research may be needed to explain conflicting results across samples In the last 12 years, there has been a great deal of correlational research on the relationships between perceived role ambiguity and role conflict and a host of hypothesized antecedents (such as tenure, formalization, boundary spanning) and consequences (such as job satisfaction, job involvement, performance, tension, propensity to leave the job). Although nearly all studies have been crosssectional, one laboratory study did find that role conflict caused a host of dysfunctional affective and behavioral outcomes (Manning, Ismail, & Sherwood, 1981) Thus, the consequences of these two types of role stress have potentially important cost implications for organizations. Whereas the costs of turnover and substandard performance are obvious, the true cost of attitudinal variables is just beginning to be understood (Cascio, 1982; Mirvis & Lawler, 1977). Therefore, efforts to obtain a better understanding of role conflict, role ambiguity, and their correlates are certainly justified.

Abnormal ion permeation through cystic fibrosis respiratory epithelium

Abstract: The epithelium of nasal tissue excised from subjects with cystic fibrosis exhibited higher voltage and lower conductance than tissue from control subjects. Basal sodium ion absorption by cystic fibrosis and normal nasal epithelia equaled the short-circuit current and was amiloride-sensitive. Amiloride induced chloride ion secretion in normal but not cystic fibrosis tissue and consequently was more effective in inhibiting the short-circuit current in cystic fibrosis epithelia. Chloride ion-free solution induced a smaller hyperpolarization of cystic fibrosis tissue. The increased voltage and amiloride efficacy in cystic fibrosis reflect absorption of sodium ions across an epithelium that is relatively impermeable to chloride ions.

Isolation of an interleukin-1-like factor from human joint effusions.

Abstract: Interleukin-1 (IL-1) is a macrophage derived mediator whose properties suggest that it could play a role in the pathology of arthritis. To test this hypothesis, joint fluids from patients with serveral different arthritides were tested. Small amounts of IL-1-like activity were recovered from many of these joint fluids after affinity chromatography over a column of rabbit anti-human IL-1. Positive fluids were obtained from patients with rheumatoid arthritis, psoriatic arthritis, Reiter's syndrome, osteoarthritis, gout, and traumatic arthritis. Upon gel filtration, the joint derived factor displayed a molecular weight distribution similar to that of IL-1 derived from human monocytes stimulated in vitro. These results suggest that IL-1 is present in joint effusions and, therefore, might contribute to joint destruction.

Human Mitochondrial DNA Variation and Evolution: Analysis of Nucleotide Sequences from Seven Individuals

Abstract: We have analyzed nucleotide sequence variation in an approximately 900-base pair region of the human mitochondrial DNA molecule encompassing the heavy strand origin of replication and the D-loop. Our analysis has focused on nucleotide sequences available from seven humans. Average nucleotide diversity among the sequences is 1.7%, several-fold higher than estimates from restriction endonuclease site variation in mtDNA from these individuals and previously reported for other humans. This disparity is consistent with the rapidly evolving nature of this noncoding region. However, several instances of convergent or parallel gain and loss of restriction sites due to multiple substitutions were observed. In addition, other results suggest that restriction site (as well as pairwise sequence) comparisons may underestimate the total number of substitutions that have occurred since the divergence of two mtDNA sequences from a common ancestral sequence, even at low levels of divergence. This emphasizes the importance of recognizing the large standard errors associated with estimates of sequence variability, particularly when constructing phylogenies among closely related sequences. Analysis of the observed number and direction of substitutions revealed several significant biases, most notably a strand dependence of substitution type and a 32-fold bias favoring transitions over transversions. The results also revealed a significantly nonrandom distribution of nucleotide substitutions and sequence length variation. Significantly more multiple substitutions were observed than expected for these closely related sequences under the assumption of uniform rates of substitution. The bias for transitions has resulted in predominantly convergent or parallel changes among the observed multiple substitutions. There is no convincing evidence that recombination has contributed to the mtDNA sequence diversity we have observed.

Dietary components that regulate serum somatomedin-C concentrations in humans

Abstract: Dietary components responsible for the regulation of somatomedin-C in humans were assessed in five adult volunteers of normal weight who were fasted for 5 d on three occasions, then refed three diets of differing composition. The serum somatomedin-C decreased from a mean prefasting value of 1.85 +/- 0.39 U/ml (+/- 1 SD) to 0.67 +/- 0.16 U/ml at the end of fasting (P less than 0.005). After refeeding for 5 d with a normal diet, the mean serum somatomedin-C increased to 1.26 +/- 0.20 U/ml. A protein-deficient (32% of control), isocaloric diet resulted in a significantly smaller increase, to a mean value of 0.90 +/- 0.24 U/ml (P less than 0.05). A diet deficient in both protein and energy led to a further fall 0.31 +/- 0.06 U/ml. The changes in somatomedin-C during fasting and refeeding correlated significantly with mean daily nitrogen balance (r = 0.90). We conclude that both protein and energy intake are regulators of serum somatomedin-C concentrations in adult humans, and energy intake may be of greater importance. The correlation between changes in somatomedin-C and nitrogen balance suggests that the former are directly related to changes in protein synthesis and may be helpful in assessing the response to nutritional therapy.

Extremes and local dependence in stationary sequences

Abstract: Extensions of classical extreme value theory to apply to stationary sequences generally make use of two types of dependence restriction: (a) a weak “mixing condition” restricting long range dependence (b) a local condition restricting the “clustering” of high level exceedances.

John Henryism and blood pressure differences among Black men.

Abstract: A community probability sample of southern, working-class, black men (N=132)between 17 and 60 years of age was administered a scale to measure the degree to which they felt they could control their environment through hard work and determination. Since the legend of John Henry—the famous, black steeldriver of American folklore—can be understood as a cultural statement about how black Americans must often attempt to control behavioral Stressors through hard work and determination, items for the scale were developed to reflect the theme of John Henryism. It was hypothesized that men scoring below the median on education but above the median on John Henryism would have higher blood pressures than any other group. The data were in line with the prediction, in that men who scored low on education and high on John Henryism had significantly higher diastolic blood pressures than men who scored above the median on both measures. Study findings are discussed in terms of the meaning that education and John Henryism may have for raising or lowering autonomic arousal when individuals encounter behavioral Stressors in everyday life. Preliminary construct validity evidence for the John Henryism Scale is also presented.

Density Functional Theory

Abstract: Contemporary quantum chemistry presents a quandry. Solution of the Schrodinger equation proceeds to higher and higher accuracy, and molecular properties are computed ever more precisely. But the understanding of molecular properties seems thereby not enhanced. The beauty that is chemistry eludes us.

Photochemistry of MLCT excited states. Effect of nonchromophoric ligand variations on photophysical properties in the series cis-Ru(bpy)2L22+

Abstract: Proprietes photophysiques des etats excites (transfert de charge metal a coordinat) emissifs, a vie courte, d'une serie de complexes cis-Ru(bpy) 2 L 2+ , (L= pyridine, pyridazine, 1/2, phenanthroline, 1/2 bipyridine, N'-methylimidazole, (amine-2 ethyl)-2 pyridine)

Metabolism, disposition, and kinetics of delta-9-tetrahydrocannabinol in men and women

Abstract: A comparative study was done in women and men of the effects of delta 9-tetrahydrocannabinol (delta 9-THC), intravenously or orally, on dynamic activity, metabolism, excretion, and kinetics. In general no differences between the two sexes were observed. delta 9-THC is converted by microsomal hydroxylation to 11-hydroxy-delta 9-THC (11-OH-delta 9-THC), which is both a key intermediate for further metabolism to 11-nor-delta 9-THC-9-carboxylic acid (11-nor-acid) by liver alcohol-dehydrogenase enzymes and a potent psychoactive metabolite. Major differences in the ratio of the concentration of 11-OH-delta 9-THC to that of delta 9-THC in plasma were found after intravenous dosing (ratio 1:10 to 20) compared with oral administration (ratio 0.5 to 1:1). The final metabolic products are the 11-nor-acids and the related, more polar acids. Urinary excretion of delta 9-THC is restricted to acidic nonconjugated and conjugated metabolites. After 72 hr mean cumulative urinary excretion, noted for both routes and for both sexes, ranged from 13% to 17% of the total dose. After 72 hr the cumulative fecal excretion for both sexes after intravenous administration ranged from 25% to 30%; after oral administration the range was 48% to 53%. Metabolites were found in the feces in large concentration in the nonconjugated form; concentrations of 11-OH-delta 9-THC were particularly noteworthy. Kinetics of delta 9-THC and metabolites were much the same for female and male subjects. For delta 9-THC, terminal-phase t1/2s for both sexes, irrespective of the route, ranged from 25 to 36 hr. A comparison of the results for AUC/dose (delta 9-THC) after oral dosing with comparable data from intravenous administration indicated bioavailability of the order of 10% to 20% for both sexes. After intravenous delta 9-THC, large apparent volumes of distribution were noted (about 10 l/kg for both sexes).

Redox Properties of Ruthenium(II) Tris Chelate Complexes Containing the Ligands 2,2′-Bipyrazine, 2,2′-Bipyridine, and 2,2/-Bipyrimidine

Abstract: The synthesis of the title chelate complexes is described The redox potentials, photophysical and photochemical properties of the excited states including lifetimes, emission quantum yields, and protonation of the remote nitrogens on the ligands are addressed 9 figures, 3 tables

Sequence analysis of somatomedin-C: confirmation of identity with insulin-like growth factor I.

Abstract: Somatomedin-C (Sm-C) was purified from Cohn fraction IV of human plasma by previously published methods. Purity was established by SDS polyacrylamide electrophoresis followed by silver staining of the gel. Amino acid analysis of an acid hydrolysate revealed no significant discrepancies from the amino acid composition of insulin-like growth factor I (IGF-I). The first 24 residues beginning at the amino terminal glycine were identical to the corresponding residues in IGF-I. Tryptic and chymotryptic degradation followed by determination of the amino acid composition and sequence of the resultant peptides was used to complete the primary structure of Sm-C. The results of these studies document that Sm-C and IGF-I are identical peptides, thus supporting previous observations that Sm-C and IGF-I are qualitatively and quantitatively indistinguishable in radioligand and biological assay systems.

Bifurcations and stability of families of diffeomorphisms

Abstract: We consider one parameter families or arcs of diffeomorphisms. For families starting with Morse-Smale diffeomorphisms we characterize various types of (structural) stability at or near the first bifurcation point. We also give a complete description of the stable arcs of diffeomorphisms whose limit sets consist of finitely many orbits. Universal models for the local unfoldings of the bifurcating periodic orbits (especially saddle-nodes) are established, as well as several results on the global dynamical structure of the bifurcating diffeomorphisms. Moduli of stability related to saddle-connections are introduced.

Relative ion permeability of normal and cystic fibrosis nasal epithelium.

Abstract: The raised transepithelial electric potential difference (PD) across respiratory epithelia in cystic fibrosis (CF) has suggested an abnormality in ion permeation. We characterized this abnormality further by measuring in the nasal epithelia of CF and normal subjects the concentration-PD relationship for amiloride, an inhibitor of cell Na+ permeability, and PD responses to superfusion with solutions of different composition. Amiloride was more efficacious in the CF subjects but the ED50 was not different from that of normals (approximately 2 X 10(-6) M). Na+ replacement by choline induced effects similar to those of amiloride, i.e. a greater depolarization in CF subjects. A 10-fold increase in the K+ concentration of the perfusate induced a small (less than 10 mV) depolarization in both subject populations. When Cl- in the perfusate was replaced by gluconate or SO2-(4) the nasal PD of normal subjects hyperpolarized (lumen became more negative) by approximately 35 mV. A significantly smaller response (less than 17 mV) was induced in CF homozygotes but not in heterozygotes (38 mV). The smaller response of CF subjects appears to reflect an absolute decrease in luminal surface Cl- permeability because pretreatment with amiloride did not increase the response to Cl- free solution (7 mV). Accordingly, three abnormalities (decreased Cl- permeability, raised PD, greater amiloride efficacy) have been identified in CF respiratory epithelia. Whereas "excessive" active Na+ transport can account for these abnormalities and the dessication of airway surface liquid, it is possible that a lower lumenal cell membrane Cl- permeability and inhibition of a potential path of Cl- secretion can also explain the observations.

Human growth hormone and somatomedin C suppress the spontaneous release of growth hormone in unanesthetized rats

Abstract: To investigate the feedback control of GH secretion, we examined the effects of human GH (hGH) and somatomedin C (SmC) on spontaneous GH secretory surges in unanesthetized, freely moving rats. Under pentobarbital anesthesia a right atrial catheter and an intracerebroventricular cannula were placed 7–10 days before the experimentation. For iv studies, hGH (0.3 U/ml-h) was infused for 6 h after an iv loading dose (0.3 U) at the beginning of the experiments. For intraventricular injections, hGH (0.1 U/ 10 μl) or SmC (500 ng/10 μl) were injected into the lateral ventricle 2 h before the experiments. The equivalent dose of crystalline BSA diluted in the same vehicle solutions was administered to the same rat as a control on a separate day. Venous blood samples were collected every 20 min for 6 h. Intravenous and intraventricular administration of crystalline BSA did not affect the typical rat GH (rGH) surges which appeared about every 3 h and reached peak values of more than 300 ng/ml. The iv infusion of hGH s...

Replication of Epstein–Barr virus in human epithelial cells infected in vitro

Abstract: Epstein-Barr virus (EBV), a member of the herpes group of viruses and the aetiological agent of infectious mononucleosis, is usually thought of as a lymphotrophic virus with the ability to transform B lymphocytes. So the association of EBV with nasopharyngeal carcinoma is puzzling, especially given the lack of success of attempts to infect epithelial cells with EBV in culture and the apparent lack of EBV receptors on epithelial cells. Circumvention of the apparent requirement for membrane receptors by techniques of transfection, microinjection and receptor transplantation has clearly demonstrated that there is no inherent barrier to EBV replication in nonlymphoid cells, including epithelial cell types. Our ability routinely to detect EBV DNA by in situ hybridization in epithelial cells of the oropharynx from persons with acute infectious mononucleosis suggests that, in vivo, EBV regularly gains access to and replicates lytically in epithelial cells. We report here in vitro evidence for direct infection by EBV and replication of the virus in cultured normal human epithelial cells.

Alzheimer's disease: genetic aspects and associated clinical disorders.

Abstract: Genetic aspects and associated clinical disorders were studied in a consecutive series of 68 men and women in whom Alzheimer's disease appeared at or before age 70. Secondary cases of dementia were found in 17 (25%) of the families, affecting 22 of the probands' siblings and parents. The cumulative incidence of Alzheimer's disease in these relatives was approximately 14% at age 75. An increased frequency of Down's syndrome was observed among relatives of the probands: a rate of 3.6 per 1,000, as compared with an expected rate of 1.3 per 1,000. A history of thyroid disease was established in 9 (19.6%) of the 46 female probands, a frequency greater than that reported in the general population. There was no excess of hematological malignancies among the blood relatives, and parental age at the time of birth of the probands did not differ from the norm. The results of this study indicate that early-onset Alzheimer's disease is associated with a genetic factor manifested in a substantial familial aggregation of dementia, a probable excess of Down's syndrome in the probands' relatives, and a possible association with thyroid dysfunction in women with this form of dementia.

Croup: An 11-Year Study in a Pediatric Practice

Abstract: The etiology and epidemiology of croup were studied in a pediatric group practice over an 11-year period, 1964 to 1975. Croup was diagnosed in 951 instances in 6,165 cases of lower respiratory tract infection (LRI) studied. As census figures of the practice clientele were available, attack rates were calculated. The incidence of total LRI was highest in the first year of life. In contrast, the attack rate for croup was highest in the second year of life; the rate declined gradually after that age. Croup was not diagnosed in the first month of life. Boys were 1.43 times more likely to develop croup than were girls. Three hundred sixty agents were isolated from the 951 croup cases. The parainfluenza viruses accounted for 74.2% of all isolates; 65% of the parainfluenza isolates were classified as parainfluenza virus type 1. Respiratory syncytial virus, influenza viruses A and B, and Mycoplasma pneumoniae were the only other agents isolated in appreciable numbers. The propensity of various agents to produce croup symptoms in children with LRI due to specific microorganisms was 58% for parainfluenzae type 1, 60% for parainfluenzae type 2, and 29% for parainfluenzae type 3; similar figures for the other agents varied from 5% to 16%. The role of the various agents in the etiology of croup varied with patient age and depended on the propensity of the agent to produce the croup syndrome and the frequency of isolation of the agent at that age. The parainfluenza viruses were the most important croup agents at all ages; respiratory syncytial virus caused croup in children less than 5 years of age whereas the influenza viruses and M pneumoniae were significant causes of croup only in children more than 5 to 6 years old. Croup occurred predominately in late fall and early winter, times when the parainfluenza viruses, especially type 1, occurred most frequently. The epidemiology of croup differs from that of bronchiolitis, pneumonia, and tracheobronchitis; knowledge of this should be helpful to the clinician caring for children with LRI.

Unique spectrum of activity of 9-[(1,3-dihydroxy-2-propoxy)methyl]-guanine against herpesviruses in vitro and its mode of action against herpes simplex virus type 1

Abstract: A guanosine analog, 9-[(1,3-dihydroxy-2-propoxy)methyl]guanine (DHPG), was found to inhibit herpes simplex virus type 1 (HSV-1), herpes simplex virus type 2, cytomegalovirus, and Epstein-Barr virus replication by greater than 50% at concentrations that do not inhibit cell growth in culture. The potency of the drug against all of these viruses is greater than that of 9-[(2-hydroxyethoxy)methyl]guanine (acyclovir). DHPG was active against HSV-1 growth during the early phase of virus replication and had no activity when added at a later time after infection. Its antiviral activity was irreversible. Thymidine partially neutralized its action. The anti-HSV-1 activity of DHPG was dependent on the induction and the properties of virus-induced thymidine kinase. Virus variants that induced altered virus thymidine kinase and became resistant to acyclovir were still as sensitive to DHPG as the parental virus. DHPG is active against five different HSV variants with induced altered DNA polymerase and resistance to acyclovir.

Sequence of developmental alterations following acute ethanol exposure in mice: craniofacial features of the fetal alcohol syndrome.

Abstract: The typical facial features of the fetal alcohol syndrome (FAS) were induced in C57B1/6J mice with acute maternal ethanol administration at gastrulation stages of embryonic development. These features include microcephaly, microphthalmia, short palpebral fissures, deficiencies of the philtral region, and a long upper lip. Scanning electron microscopy (SEM) analysis of embryos 24 hours following initial ethanol exposure at 7 days 0 hours of gestation revealed an obvious size reduction in the neural plate, which was particularly noticeable in the forebrain region. As expected, deficiencies in neural plate development at these early stages result in abnormal brain and eye formation. SEM analysis of later embryonic stages revealed the development of closely set olfactory placodes with resultant deficiencies in the medial nasal prominences (that area responsible for forming the philtral region of the upper lip, the alveolar ridge contained the upper incisors, and the anterior portion of the hard palate--the primary palate). Cleared skeletal preparations of affected newborns had marked premaxillary bone deficiencies. One of the most prevalent known human teratogens has a major malformation-inducing effect on gastrulating embryos, a developmental stage present in human embryos prior to pregnancy recognition by most women.