Showing papers by "Research Triangle Park published in 1988"
TL;DR: The architecture of the edge detector presented is highly pipeline to perform the computations of gradient magnitude and direction for the output image samples and has been demonstrated with a prototype system that is performing image edge detection in real time.
Abstract: The architecture of the edge detector presented is highly pipeline to perform the computations of gradient magnitude and direction for the output image samples The chip design is based on a 2- mu m, double-metal, CMOS technology and was implemented using a silicon compiler system in less than 2 man-months It is designed to operate with a 10-MHz two-phase clock, and it performs approximately 200*10/sup 6/ additions/s to provide the required magnitude and direction outputs every clock cycle The function of the chip has been demonstrated with a prototype system that is performing image edge detection in real time >
743 citations
472 citations
Journal Article•
TL;DR: A strong correlation was observed between the relative hepatocarcinogenicity of DEHP and Wy-14,643 and the ability to induce a persistent increase in replicative DNA synthesis, emphasizing the possible importance of cell replication in the mechanism of PP-induced hepatOCarcinogenesis.
Abstract: The mechanism of hepatocarcinogenesis caused by peroxisome proliferators (PP) is poorly understood, making it difficult to predict the carcinogenicity of PP to rodents or other species. It has been suggested that the carcinogenic potential of individual PP in rodents is correlated with the degree of PP-induced hepatic peroxisome proliferation. To evaluate this possible correlation, di(2-ethylhexyl)phthalate (DEHP) at 1.2% and [4-chloro-6-(2,3-xylidino)-2-pyrimidinylthio]acetic acid (Wy-14,643) at 0.1% were fed to male F-344 rats for up to 365 days and hepatocytic peroxisome proliferation and DNA replication were measured. All rats fed Wy-14,643 for 365 days had numerous grossly visible nodules in comparison to none in the livers of DEHP-fed or control rats. Despite this difference in the induction of tumors, both DEHP and Wy-14,643 increased the peroxisomal volume density 4- to 6-fold from 8 to 365 days of treatment. Peroxisomal beta-oxidation enzyme activities were increased 8-fold by both DEHP and Wy-14,643 after 18 days. At later time points (77 to 365 days), these enzyme activities were about 25% higher in livers of Wy-14,643- than DEHP-fed rats. DEHP or Wy-14,643 increased absolute liver weights 50 to 75% above controls after 18 to 365 days of feeding. Labeling of hepatocyte nuclei with a single injection of tritiated thymidine revealed a rapid burst in replicative DNA synthesis in both DEHP and Wy-14,643-fed rats, with a return to control levels by 4 days. Additional rats were implanted with 7-day osmotic pumps containing tritiated thymidine. With this more extended method of labeling a 5- to 10-fold increase in replicative DNA synthesis was observed in rats receiving Wy-14,643 for 39 to 365 days as compared to DEHP-fed rats or controls. In conclusion, when performed under conditions similar to the tumorigenicity studies, the degree of peroxisome proliferation correlated poorly with the relative hepatocarcinogenicity of DEHP and Wy-14,643. However, a strong correlation was observed between the relative hepatocarcinogenicity of DEHP and Wy-14,643 and the ability to induce a persistent increase in replicative DNA synthesis. These data emphasize the possible importance of cell replication in the mechanism of PP-induced hepatocarcinogenesis.
356 citations
TL;DR: The results of this study show that mature hamster oocytes contain significantly more glutathione (GSH), about 8 mM, and hence more disulfide reducing power, as compared with GV or pronuclear oocytes, which is the first evidence that modulation of GSH levels during oocyte maturation and fertilization may be a mechanism by which sperm nuclear decondensing activity is regulated.
342 citations
TL;DR: The data show that the antiproliferative effect of IFN-gamma through induction of indoleamine 2,3-dioxygenase, with a consequent L-tryptophan deprivation, is an effective means of regulating cell growth.
Abstract: The antiproliferative effects of interferon alpha (IFN-alpha) and interferon gamma (IFN-gamma) were found to be cell-dependent. Among the human cell lines examined, IFN-gamma had a greater antiproliferative effect against cell lines that exhibited induction of indoleamine 2,3-dioxygenase, such as the KB oral carcinoma or WiDr colon adenocarcinoma, than against those that lacked the enzyme activity, such as the SW480 colon adenocarcinoma or NCI-H128 small-cell lung carcinoma. Induction of this dioxygenase showed a clear temporal relationship with increased metabolism of L-tryptophan and the depletion of this amino acid in the culture medium. While 70-80% of L-tryptophan remained in the medium of IFN-alpha- or vehicle-treated cells, virtually all of this amino acid was depleted in the medium of the IFN-gamma-treated group following 2-3 days of culture. Supplementing the growth medium with additional L-tryptophan reversed the antiproliferative effect of IFN-gamma against KB cells in a dose- and time-dependent manner. The antiproliferative effects of IFN-alpha and IFN-gamma on SW480 and NCI-H128 cells, which are independent of the dioxygenase activity, and the inability of added L-tryptophan to reverse the effects of IFN-gamma in WiDr cells suggest multiple mechanisms of action of the IFNs. The data show that the antiproliferative effect of IFN-gamma through induction of indoleamine 2,3-dioxygenase, with a consequent L-tryptophan deprivation, is an effective means of regulating cell growth.
244 citations
TL;DR: There were important qualitative differences in the effects of CAR and CDM on reactions to handling and the reflex tests in that CDM increased excitability and enhanced responses to several stimuli but CAR either had no effect or decreased these measures.
238 citations
TL;DR: A static headspace method, Equilibrium Partitioning in Closed Systems (EPICS), was used to measure Henry's Law constant, and the batch air stripping method was used as a check.
234 citations
TL;DR: The development of a method for determining hydrophobicity constants for small, organic molecules by reversed-phase liquid chromatography is presented and values of log k'w are shown to be largely column-independent as long as the hydrophobic properties of columns are similar.
Abstract: The development of a method for determining hydrophobicity constants for small, organic molecules by reversed-phase liquid chromatography (RPLC) is presented. The method uses capacity ratios measured at a number of different compositions of methanol to obtain derived values, denoted log k'w, upon which a new scale of hydrophobicity constants can be developed. This scale eliminates potential problems such as peak inversion that hamper RPLC methods using isocratic data to estimate hydrophobicity. The differential hydrogen bond effect observed in most correlations of RPLC data with logarithms of octanol-water partition coefficients (log Po/w) for compounds of opposite net hydrogen bonding capabilities (noncongeners) was minimized by adding trace quantities of n-decylamine and 1-octanol to the eluent and using an octyl-modified silica gel stationary phase. Values of log k'w are shown to be largely column-independent as long as the hydrophobic properties of columns are similar. The correlation of log k'w values with the logarithms of bovine serum albumin binding constants (log 1/C) is shown to be statistically indistinguishable from the correlation of log 1/C with log Po/w, indicating that this data models log 1/C as well as log Po/w for these compounds. Additionally, the chromatographic system is automatable and thus capable of higher sample throughput than measurements of log Po/w by the shake-flask method.
227 citations
Patent•
04 May 1988TL;DR: A body lumen measuring instrument for insertion into a body passageway such as a bronchial tube or the like in order to determine the interior lumen diameter and/or axial length of the passagway at a predetermined location is described in this article.
Abstract: A body lumen measuring instrument for insertion into a body passageway such as a bronchial tube or the like in order to determine the interior lumen diameter and/or axial length of the passageway at a predetermined location. This instrument can also be used to aid selection of a radioisotope capsule of proper size to be properly positioned at a specific location for tumor treatment. The measuring instrument includes a flexible sleeve having a handle secured to one end. A cable is slidably positioned within the sleeve and secured at one end to a slide actuator within the handle and at the other end terminates in a probe adapted for determining body passageway size under endoscopic observation. A measurement scale is associated with an indicator on the slide actuator in order to display the passageway size.
189 citations
TL;DR: A hypothetical ordering of the frequency-response profile provides the basis for future experimental designs to test each possible interaction model and for their connection to the calcium-ion efflux endpoint.
Abstract: The frequency dependence of electromagnetic field-induced calcium-ion efflux from chicken brain tissues has been examined at 15-Hz intervals over the range 1-510 Hz The electric field component was 15 Vrms/m and the magnetic component varied between 59 and 69 nTrms No patterns of response as a function of frequency could be readily discerned when the differences in mean efflux values between exposed and sham samples were compared However, the calculated P-value, a function that combines at each frequency the difference between the means of the exposed and sham groups with the variance of each group, does provide a basis for hypothesizing the existence of three frequency-dependent patterns in the data One pattern includes all the highly significant (P less than 01) responses which occur between 15 and 315 Hz, at 30-Hz intervals; two independent trials at 165 Hz, giving nonsignificant responses (P greater than 5), break this pattern into two groups of five frequencies each, which is contrary to the expected result for a simple Lorentz-force interaction However, another pattern of significant results at 60, 90, and 180 Hz, but not at 300 Hz, is consistent with a Lorentz-force model A third pattern, composed of only one significant response at 405 Hz, is very close to the resonance predicted on a linear extrapolation from high-frequency data for 13carbon atoms This hypothetical ordering of the frequency-response profile provides the basis for future experimental designs to test each possible interaction model and for their connection to the calcium-ion efflux endpoint
173 citations
TL;DR: In this article, the same six species of sperm nuclei were induced to undergo decondensation in vitro by treatment with DTT and detergent, and the resulting changes in nuclear size were monitored by phase-contrast microscopy and flow cytometry.
Abstract: To assess the structural stability of mammalian sperm nuclei and make interspecies comparisons, we microinjected sperm nuclei from six different species into hamster oocytes and monitored the occurrence of sperm nuclear decondensation and male pronucleus formation. The time course of sperm decondensation varied considerably by species: human and mouse sperm nuclei decondensed within 15 to 30 min of injection, and chinchilla and hamster sperm nuclei did so within 45 to 60 min, but bull and rat sperm nuclei remained intact over this same period of time. Male pronuclei formed in oocytes injected with human, mouse, chinchilla, and hamster sperm nuclei, but rarely in oocytes injected with bull or rat sperm nuclei. However, when bull sperm nuclei were pretreated with dithiothreitol (DTT) in vitro to reduce protamine disulfide bonds prior to microinjection, they subsequently decondensed and formed pronuclei in the hamster ooplasm. Condensed rat spermatid nuclei, which lack disulfide bonds, behaved similarly. The same six species of sperm nuclei were induced to undergo decondensation in vitro by treatment with DTT and detergent, and the resulting changes in nuclear size were monitored by phase-contrast microscopy and flow cytometry. As occurred in the oocyte, human sperm nuclei decondensed the fastest in vitro, followed shortly by chinchilla, mouse, and hamster and, after a lag, by rat and bull sperm nuclei. Thus species differences in sperm nuclear stability exist and appear to be related to the extent and/or efficiency of disulfide bonding in the sperm nuclei, a feature that may, in turn, be determined by the type(s) of sperm nuclear protamine(s) present.
TL;DR: It was concluded that excitatory amino acid transmission contributes in an important, but non-critical way to amygdala kindling.
TL;DR: Comparison with available natural history data suggests that zidovudine therapy is associated with increased 44-week survival of post-PCP patients with acquired immunodeficiency syndrome.
Abstract: Through a compassionate plea program (Treatment Investigational New Drug), 4805 patients with acquired immunodeficiency syndrome who previously had experiencedPneumocystis cariniipneumonia (PCP) received zidovudine (Retrovir, formerly azidothymidine). Overall survival at 44 weeks after initiation of therapy was 73% ( ± 2.1%). A positive association was found between survival and pretherapy clinical status as defined by hemoglobin level, functional ability, and stage of disease as measured by time since diagnosis of PCP. For patients with baseline hemoglobin levels of 120 g/L or greater, Karnofsky scores of 90 or greater, and PCP diagnosis within 90 days prior to initiation of therapy, 44-week survival was 88%. Adverse clinical experiences associated with zidovudine therapy were consistent with those from a double-blind, placebo-controlled trial. Survival experience of this large and diverse cohort is consistent with, and extends data from, this clinical trial. Comparison with available natural history data suggests that zidovudine therapy is associated with increased 44-week survival of post-PCP patients with acquired immunodeficiency syndrome. (JAMA1988;260:3009-3015)
TL;DR: DEHP was not teratogenic at any dose tested in Fischer 344 rats when administered in the feed throughout gestation but did produce maternal and other embryofetal toxicity at 1.0, 1.5, and 2.0%; in contrast, DEHP administration throughout gestation in CD-1 mice resulted in an increased incidence of malformations.
TL;DR: In this article, the potential impact of drug-abuse treatment in combatting the AIDS epidemic is discussed, and it is shown that drug abuse treatment results in substantial declines in the use of heroin, cocaine, prescription psychotherapeutic drugs, and other drugs in the year after treatment.
Abstract: Drug-abuse treatment may have important direct and indirect effects on restricting the spread of infection with human immunodeficiency virus by decreasing the prevalence of intravenous drug use and by decreasing regular drug use that impairs the immune system. Drug-abuse treatment results in substantial declines in the use of heroin, cocaine, prescription psychotherapeutic drugs, and other drugs in the year after treatment. Declines are closely related to the length of time spent in treatment; treatment duration of greater than or equal to 6 months has a significant impact on drug use after treatment. The potential impact of drug-abuse treatment in combatting the AIDS epidemic is discussed.
TL;DR: A genetically homogeneous population of Plasmodium falciparum prepared by a single erythrocyte micromanipulation technique was used to produce lines of P. falcIParum resistant to mefloquine hydrochloride in vitro.
TL;DR: It is demonstrated the transfer and expression of a foreign chimeric gene in the grass species, Dactylis glomerata L. Pooideae, which includes the small grain cereals, from which transformed plants have not yet been obtained.
Abstract: We have demonstrated the transfer and expression of a foreign chimeric gene in the grass species, Dactylis glomerata L. This species is a member of the Gramineae sub-family Pooideae, which includes the small grain cereals, from which transformed plants have not yet been obtained. A chimeric hygromycin-resistance gene was introduced into protoplasts isolated from an embryogenic suspension culture, using heat shock followed by electroporation or polyethylene glycol treatment. Cell colonies resistant to 20 μg/ml hygromycin were selected in liquid medium using an agarose bead type culture system. Transformed calli were identified by Southern hybridization. Embryogenic callus was induced to regenerate plants and transformed plants were shown to contain the hygromycin resistance gene.
TL;DR: The findings were interpreted as being consistent with the hypothesis that alcohol effects violence directly, acting through the acute effects of use, rather than indirectly through the effects of underlying or mediating factors.
Abstract: While the empirical association of drinking and problem drinking to violence is well established, the etiological nature of the relationship is poorly understood. Using data collected from 1,149 convicted male felons, the acute (drinking just before the violent event) and chronic (a psychiatric diagnosis of alcohol abuse or dependence) effects of alcohol use on violence were analyzed. Logistic regression models were used to examine the relationship of acute and chronic alcohol effects to incarceration for a violent offense and arrest for a violent offense, with demographic and criminal history factors controlled. The acute effects of alcohol were found to be significantly associated with incarceration for a violent offense, but the net explanatory capacity of acute alcohol effects was not large. Chronic alcohol effects were not significantly associated with incarceration for a violent offense or arrest for a violent offense in the previous year. The findings were interpreted as being consistent with the hypothesis that alcohol effects violence directly, acting through the acute effects of use, rather than indirectly through the effects of underlying or mediating factors.
TL;DR: The effects of acute inhalation exposure to methyl bromide (MeBr) on the olfactory epithelium of male F-344 rats was investigated by morphologic examination of animals killed at varying timepoints during and following exposure to 200 ppm MeBr 6 hr/day for 5 days, demonstrating that the Olfactory mucosa is highly sensitive to the toxic effects of MeBr.
TL;DR: There is little evidence for strong associations between this phenotype and the polymorphisms at the DNA level, contrary to a simple prediction based on the theory of mutation selection-balance of partially recessive deleterious mutants which predicts less variation on X chromosomes.
Abstract: Restriction map polymorphism in a 13-kb region of the Zw locus in Drosophila melanogaster was investigated for 64 X chromosome lines with seven 6-cutter and ten 4-cutter restriction enzymes. A total of 203 restriction sites were scored, of which 20 were found to be polymorphic. The estimated nucleotide variation for this region for overall data (pi = 0.003 and 0.001, and theta = 0.003 and 0.002, for 4-cutter and 6-cutter studies, respectively) was smaller than that reported for most regions studied in D. melanogaster. It was found that the Slow allozyme has a larger nucleotide variation and haplotype diversity than the Fast allozyme. Results suggest the relatively recent divergence of the Fast allozyme from the Slow allozyme. Glucose 6-phosphate dehydrogenase (G6PD) activity was measured as a phenotype of the Zw locus. A significant difference in G6PD activity between allozymes was detected. The between-line effect was highly significant within the Slow allozyme, but was not significant within the Fast allozyme. Although a direct causative link could not be established, these results suggest an association between the amounts of quantitative and molecular genetic variation at the Zw locus region.
TL;DR: The effects of 3'-azido-3'-deoxythymidine (AZT) on the deoxynucleotide pools of three human cell lines, HL-60, H-9, and K-562, were determined and the concentration of thymidine, and to a lesser extent deoxyuridine, increased in the media of treated cells.
TL;DR: The complete primary sequence of the precursor protein for spinach nitrite reductase has been deduced from cloned cDNAs, which most likely serve as a transit peptide involved in directing this nuclearencoded protein into the chloroplast.
Abstract: The main nitrogen source for most higher plants is soil nitrate. Prior to its incorporation into amino acids, plants reduce nitrate to ammonia in two enzymatic steps. Nitrate is reduced by nitrate reductase to nitrite, which is further reduced to ammonia by nitrite reductase. In this paper, the complete primary sequence of the precursor protein for spinach nitrite reductase has been deduced from cloned cDNAs. The cDNA clones were isolated from a nitrate-induced cDNA library in two ways: through the use of oligonucleotide probes based on partial amino acid sequences of nitrite reductase and through the use of antibodies raised against purified nitrite reductase. The precursor protein for nitrite reductase is 594 amino acids long and has a 32 amino acid extension at the N-terminal end of the mature protein. These 32 amino acids most likely serve as a transit peptide involved in directing this nuclearencoded protein into the chloroplast. The cDNA hybridizes to a 2.3 kb RNA whose steady-state level is markedly increased upon induction with nitrate.
TL;DR: Thrombin activation of protein kinase C phosphorylates and inactivates a signaling protein which is common to both thrombin and alpha 2-adrenergic receptors, suggesting that alpha i maintains the throm bin receptor in a state which can couple to phospholipase C when activated with thromin.
University of California, Los Angeles1, California Air Resources Board2, Research Triangle Park3, California Health and Human Services Agency4, University of South Florida5, California Institute of Technology6, Brigham Young University7, Southern California Edison8, National Oceanic and Atmospheric Administration9, University of Calgary10, Ford Motor Company11, Battelle Memorial Institute12, University of Denver13, University of California, Riverside14
TL;DR: The results from the three annular denuders do not agree; the ratios of means to the DDM value are 1.0, 0.8 and 0.6 as mentioned in this paper.
TL;DR: In this paper, microspheres containing 13-16% l-methadone were prepared from three biodegradable polymers, poly( l -lactic acid), PLLA; poly (glycolic acid-co- l-lactic acids), PGLA; and poly (ϵ-caprolactone-co − l - lactic acid) PCL-LA, using the solvent evaporation method.
TL;DR: The approach used here provides a sensitive index of clastogenic damage and offers unique opportunities for investigating the determinants of cytogenetic damage in humans.
Abstract: Recent studies have demonstrated that in the absence of spleen function, frequencies of micronuclei (Howell-Jolly bodies) in peripheral blood rbcs can be used to measure in vivo cytogenetic damage. Among 20 subjects studied greater than or equal to 6 months after splenectomy, 1 had a frequency of micronucleated rbcs more than an order of magnitude higher than rates for the others. Initial data suggested that this subject was mildly folate-depleted, and a therapeutic trial with folate rapidly reduced the frequency of micronucleated rbcs to normal values. These observations suggest a need to evaluate further the contribution of mild levels of folate depletion to spontaneous chromosomal damage. The approach used here provides a sensitive index of clastogenic damage and offers unique opportunities for investigating the determinants of cytogenetic damage in humans.
TL;DR: In this article, a fundamental study was carried out for low-temperature deep oxidation of n-hexane and benzene over a 0.1 % Pt, 3% Ni/γ-Al2O3 catalyst.
TL;DR: There are good reasons for health departments to place high priority on prevention efforts directed to prostitutes: 1) prostitutes often have other risky behaviors such as drug use; and 2) prostitutes are reachable, being a group which is already in the health care system administered by health departments.
Abstract: With increasing competition for resources, health departments are faced with the question of whether to target female prostitutes as a high priority component of AIDS prevention strategy. Prostitutes are considered to be a reservoir for transmission of certain sexually transmitted diseases (STDs). However, a variety of studies suggest that human immunodeficiency virus (HIV) infection in prostitutes follows a different pattern than that for STDs: HIV infection in non-drug using prostitutes tends to be low or absent, implying that sexual activity alone does not place them at high risk, while prostitutes who use intravenous drugs are far more likely to be infected with HIV. Emerging data from heterosexual groups similarly suggest a low rate of heterosexual transmission, particularly from women to men. Prostitutes who do not use intravenous drugs probably face their highest risk from steady partners who may be infected with HIV and other STDs and with whom barrier protection is generally not used. Nevertheless, there are good reasons for health departments to place high priority on prevention efforts directed to prostitutes: 1) prostitutes often have other risky behaviors such as drug use; and 2) prostitutes are reachable, being a group which is already in the health care system administered by health departments.
TL;DR: There was a significant correlation between the infusion rate of mivacurium required to maintain 95% twitch depression and the plasma cholinesterase activity of individual subjects.
Abstract: Mivacurium chloride (BWB1090U) is a new, short-acting non-depolarizing neuromuscular blocking agent. It is a synthetic bis-benzylisoquinolinium diester, which is hydrolysed rapidly by plasma cholinesterase. This study compares mivacurium, atracurium and vecuronium by continuous i.v. infusion. The duration of mivacurium infusion ranged from 29.5 to 286 min. The steady state infusion rates necessary to maintain 95 (SEM 4)% twitch suppression were: mivacurium 8.3 (0.7) μg kg−1 min−1; atracurium 7.9 (0.4) μg kg−1 min−1; vecuronium 1.2 (0.3) μg kg−1 min−1. Following infusions of mivacurium, various recovery times (for example: 25–75%, 6.9 (0.3) min; 25–95%, 11.0 (0.4) min; 5–95% 14.5 (0.4) min) did not differ significantly from those following single bolus doses. Recovery times following cessation of mivacarium infusions were approximately 50% of those for equivalent durations of infusion of atracurium (10.9 (0.3) min for 25–75% recovery and 26.6 (0.4) min for 5–95% recovery). For vecuronium, corresponding recovery times were 13.8 (0.9) and 32.0 (1.2) min, respectively. Comparative recovery times for mivacurium were 40–50% of those for vecuronium. There was a significant correlation between the infusion rate of mivacurium required to maintain 95% twitch depression and the plasma cholinesterase activity of individual subjects.
TL;DR: 1,3-Dinitrobenzene produced profound and specific lesions in the seminiferous tubules, and recovery was slow and incomplete, and atrophic tubules seemed to form if the normal cellular associations were not reestablished within 24 days, possibly due to the inability of Sertoli cells to reorganize the synchrony of germ cell development.
Abstract: This study determined the quantitative and qualitative histopathologic effects of a single oral dose of 1,3-dinitrobenzene (48 mg/kg) on the rat testis from 1 to 175 days postexposure. The testis was damaged severely by hour 24, as evidenced by increased numbers of regressive seminiferous tubules that exhibited degenerating pachytene spermatocytes, chromatin margination in spermatids, giant cells, deformed spermatid heads, retained spermatids, and reduced numbers of meiotic figures. The major effects during the first 48 hours posttreatment were degeneration or exfoliation of pachytene spermatocytes and round spermatids and the retention of step 19 spermatids. These regressive effects continued until 24 days, after which the tubules either recovered or became atrophic. At the end of the study (175 days), three males were normal, one had regressed testicles, and three males had atrophic tubules (15 to 45%). Several cellular abnormalities were common throughout the period. In addition, the frequency of the stages of spermatogenesis was altered, an indication of a disturbance in the kinetics of spermatogenesis. 1,3-Dinitrobenzene produced profound and specific lesions in the seminiferous tubules, and recovery was slow and incomplete. Atrophic tubules seemed to form if the normal cellular associations were not reestablished within 24 days, possibly due to the inability of Sertoli cells to reorganize the synchrony of germ cell development.