Showing papers by "Tufts University published in 1977"
TL;DR: A new method for the detection of RNA–DNA hybrids in cytological preparations is described with significant advantages over the autoradiographic procedures used so far, and the locations of hybrid molecules on polytene chromosomes are revealed.
Abstract: WE describe here a new method for the detection of RNA–DNA hybrids in cytological preparations with which we have revealed the locations of hybrid molecules on polytene chromosomes. The critical reagent is an antiserum raised in rabbits against poly(rA)·poly(dT) complexed with methylated bovine serum albumin, originally described by Stollar1. The specificity and resolving power of the indirect immunofluorescence procedure are demonstrated using in situ hybridisation of 5S rRNA (ribosomal RNA) to polytene chromosomes of Drosophila melanogaster as a model system. The method has significant advantages over the autoradiographic procedures2–5 used so far.
303 citations
TL;DR: Experiments with recombinant-inbred lines, derived from C57Bl/6By and BALB/cBy mice, suggest that the initial response to cocaine and the development of sensitization are controlled by different genetic determinants.
Abstract: Repeated administration of cocaine to B6AF1/J mice increased their running response to 20 mg/kg cocaine as much as four-fold over the response to the first injection. After four daily injections, the extent of the increase was proportional to the dose of cocaine that was used for pretreatment. Sensitization persisted for as long as 2 months after the last injection of cocaine. Cocaine-pretreated mice did not show an increased running response to either morphine or d-amphetamine. The response to cocaine was increased two-fold by treatment with morphine, and three-fold by pretreatment with d-amphetamine. Pretreatment with either imipramine or reserpine did not produce sensitization to cocaine. There was no correlation between cocainesensitization and whole-brain catecholamine levels. There were marked differences in both the running response to cocaine and the extent of cocaine sensitization between the parental strains, C57B1/6J and A/J. Experiments with recombinant-inbred lines, derived from C57Bl/6By and BALB/cBy mice, suggest that the initial response to cocaine and the development of sensitization are controlled by different genetic determinants.
249 citations
TL;DR: In 6 adolescent rhesus monkeys, horseradish peroxidase (HRP) was injected into 6 regions of the dorsalateral convexity of the prefrontal granular cortex, and a horizontal band of HRP-labeled neurons which waxed and waned in cell density may well represent a vertical type of organization to the neurons which give rise to the interhemispheric cortical afferents to prefrontalgranular cortex in the monkey.
200 citations
TL;DR: The ad hoc Committee on Behavioral Tcrminology, convened at the Conference on Sensory Transduction in Microorganisms in Santa Barbara, California, in January 1976, has considered recommendations for uniform naming of stimulus-induced movement responses of microorganisms.
Abstract: The ad hoc Committee on Behavioral Tcrminology convened at the Conference on Sensory Transduction in Microorganisms in Santa Barbara, California, in January 1976, has considered recommendations for uniform naming of stimulus-induced movement responses of microorganisms (bacteria, motile algae, protozoa, sperm cells, etc.). We wish to emphasize that the terminology recommended by us is not meant to be used throughout every scientific publication, and also that it is not necessarily restricted to microorganisms. We are mostly concerned with usage in titles, because of the importance of title-based literature search procedures. Once an unambiguous term has been introduced, an abbreviation or othcr simplification will often be the preferred means of identifying the phenomenon under study, except in legends of figures. The following terminology, based on the original work by Pfeffer (1904), Kuehn (1919) and Fraenkel and Gunn (1 960), is recommended, and can be modified or extended when novel types of behavior are discovered.
179 citations
TL;DR: In 6 adolescent rhesus monkeys, unilateral injections of horseradish peroxidase (HRP) were made into 6 regions on the convexity of the prefrontal granular cortex, and the HRP-positive neurons that comprised the intrahemispheric cortical afferents to prefrontalgranular cortex were located primarily in layer iii.
175 citations
TL;DR: The results suggest that the superoxide-forming enzyme from human neutrophils is a FAD-requiring enzyme, and particle extracted with detergent prior to assay show little activity if FAD is omitted from the assay mixture.
171 citations
TL;DR: There were no appreciable histopathologic differences between the accessory gland and the main gland in the same facial half and Aging changes, such as decreased glandular elements, increased fat, and increased fibrous connective tissue, were not more extensive in the accessory glands than in the main glands.
169 citations
TL;DR: Preliminary evidence is reported that the latter type of assay may significantly improve the usefulness of ferritinaemia as a tumour marker.
Abstract: SMALL amounts of ferritin are found in serum in normal and pathological states1,2, usually at levels directly related to the amount of tissue storage iron3,4. This relationship, however, does not hold in many cancers where grossly elevated levels can occur without a corresponding increase in iron stores5–9. These latter findings suggest a possible use of ferritinaemia in cancer diagnosis but the value of this test has not been clearly established Such use is complicated by the multiple potential sources of the serum ferritin which could affect its type as well as its amount. Much of the ferritin in cancer sera may reflect increased iron stores arising from chronic anaemia or from transfusions in treated patients. Some may also come from nonspecific tissue damage. The high levels of ferritin synthesis in some cancer cells10 and the presence in serum of isoferritins characteristic of some cancer and foetal tissues11,12, however suggest that much of the ferritin may come directly from cancer cells. If so, selective quantitation of these isoferritins may provide specificity in possible serodiagnosis. The multiple isoferritins found in most human tissues seem to be hybrid molecules composed of different proportions of two subunit types13. One type predominates in liver and spleen isoferritins, and the other in the more acidic isoferritins in heart, tumours and HeLa cells14. Different isoferritin populations can be distinguished immunologically, apparently on the basis of their subunit composition14,15. Ferritin is usually assayed by immunological methods, with crystalline liver or spleen ferritins as immunising antigens and reference standards. These ferritins consist almost entirely of the liver-type subunit15. Consequently, most assays based on these ferritins have only a low reactivity for the more acidic ‘carcinofoetal’ isoferritins which may contain less than 20% of the liver-type subunit14,15. We have, therefore, tested a variety of cancer sera and compared the apparent levels of ferritin given by a standard ‘liver-type’ assay with levels given by an assay whose specificity is directed against the more acidic isoferritins15. We report here preliminary evidence that the latter type of assay may significantly improve the usefulness of ferritinaemia as a tumour marker.
155 citations
TL;DR: It appears that this highly reactive species of oxygen can be produced in several biochemical systems without the use of light and its reactions may account for some types of cell damage.
134 citations
TL;DR: The filling defects in open-angle glaucoma appear to be specific, indicating that the blood supply to the anterior portion of the optic nerve is involved, as in ischemic optic neuropathy.
Abstract: • An Improved technique for high-contrast, high-resolution fluorescein angiography of the optic disc has been developed that almost eliminates pseudo-fluorescence. Fluorescein angiography of the optic disc was performed on normal, ocular hypertensive, and glaucomatous patients. Rapid-sequence angiograms in the early arterial phases have demonstrated localized areas of hypofluorescence or filling defects of the optic disc. Two types of fluorescein filling defects were observed—absolute and relative. The number of absolute filling defects, which increased with degree of visual field loss, was greater in glaucomatous than in ocular hypertensive or normal eyes. Similarly, ocular hypertensive eyes showed a larger number of discs with filling defects than normal eyes. It is postulated that relative defects progress to absolute filling defects, which may be an indication of impending loss of visual field. ( Arch Ophthalmol 95:1961-1974, 1977)
124 citations
TL;DR: These studies demonstrate than factor X deficiency associated with systemic amyloidosis is due to binding of factor X to body tissue, probably within the circulatory system.
Abstract: To determine the metabolic fate of factor X in primary amyloidosis associated with factor X deficiency, we examined the pathways of its catabolism in a man with this syndrome. Intravenous infusion of human or bovine 131I-labeled factor X established a triphasic plasma clearance pattern for factor X. About 85 per cent of the factor X disappeared, with a disappearance half-time of less than 30 seconds. A second and third phase showed a T1/2 of 90 minutes and nine hours respectively. 131I-labeles factor X in plasma did not appear to be rapidly modified or degraded. Relatively minor quantities of 131I were cleared into the urine. We observed a diffuse distribution of radioactivity over the body surface, with a concentration in the hepatic and splenic regions. These studies demonstrate than factor X deficiency associated with systemic amyloidosis is due to binding of factor X to body tissue, probably within the circulatory system.
TL;DR: The results suggest that certain bacteria play a role in the pathogenesis of enterocolitis in this model.
TL;DR: The asymmetry of function revealed in both experiments suggests that the left hemisphere is in some sense specialized for verbal functions, and the right hemisphere for nonverbal functions by the age of 3.
TL;DR: A technique of enlarging the lumen of the distal arch and thereby further lowering the gradient has been found effective and is presented.
TL;DR: It was observed that electromyographic activity does not always correlate with urethral resistance but must be interpreted in conjunction with other urodynamic parameters, such as urethrals pressures, urinary flow rates and voiding cystourethrography.
TL;DR: The results indicate that the quantity of ferritin measured by radioimmunoassays is markedly affected by the isoferritin and subunit composition of the ferritIn sample as well as by the nature of the antiferritin antibodies.
TL;DR: Thyrotropin-releasing hormone is present in the skin of the frog (Rana pipiens) in concentrations twice that found in the hypothalamus of this amphibian and a skin extract shows biologic activity appropriate to its immunoreactive content.
Abstract: Thyrotropin-releasing hormone, a hypothalamic tripeptide that stimulates the secretion of pituitary thyroid-stimulating hormone in mammalian species and is widely distributed throughout the brain of vertebrates, is present in the skin of the frog (Rana pipiens) in concentrations twice that found in the hypothalamus of this amphibian. A skin extract shows biologic activity appropriate to its immunoreactive content. Apart from the brain and spinal cord, immunoreactive thyrotropin-releasing hormone is found only in the blood and retina in significant concentrations. The results imply that frog skin is a huge endocrine organ that synthesizes and secretes this hormone.
TL;DR: The serum ferritins were very similar to the natural apoferritin from liver in all respects and corresponded to only the most basic isoferritins in liver.
Abstract: Serum ferritins from a patient with haemochromatosis and from a patient with transfusional siderosis were compared with tissue isoferritins on the basis of their iron content, isoferritin spectrum and immunological properties. Both serum ferritins had a low iron content and corresponded to only the most basic isoferritins in liver. The serum ferritins were very similar to the natural apoferritin from liver in all respects.
TL;DR: Patients with inoperable metastatic malignant melanoma, excluding those with cutaneous metastases only, were randomized to one of three drug treatments: DTIC alone, methyl‐CCNU alone, or the combination DTIC plus methyl‐SSU.
Abstract: This report is the result of an Eastern Cooperative Oncology Group (ECOG) study. Four hundred and 15 patients with inoperable metastatic malignant melanoma, excluding those with cutaneous metastases only, were randomized to one of three drug treatments: DTIC alone, methyl-CCNU alone, or the combination DTIC plus methyl-CCNU. Responses were seen in 14% of DTIC patients (19/127), 15% of methyl-CCNU patients (18/119) and 14% of DTIC plus methyl-CCNU patients (18/122). Duration of response was the same (14 weeks) for all three treatment groups. There was no difference among the treatments in achieving complete responses. Survival was improved significantly for responders (50 weeks) compared with nonresponders (15 weeks) regardless of treatment regimen. Toxicities were generally tolerable. DTIC caused significantly more gastrointestinal toxicity than methyl-CCNU. Methyl-CCNU caused significantly more bone marrow toxicity than DTIC. There were three drug-related deaths. All occurred in patients on combination DTIC plus methyl-CCNU. Important pretreatment characteristics that favor response are ambulatory status, female, less than 50 years old, no prior chemotherapy and no liver or brain metastases. Patients with favorable characteristics combinations had a 30% response rate, while those with unfavorable characteristic combinations had only a 9% response rate.
TL;DR: It is determined that giant-headed, gene 2-defective particles containing several genome lengths of DNA per head are fully infective on exo V + hosts even though part of the parental DNA is degraded to acid-soluble fragments early after infection.
TL;DR: Massive liver damage and marked elevation of serum glutamic-oxaloacetic transaminase was observed after a single injection of 50 mg per kg cocaine-HC1, which led to increased sleep time after pentobarbital, and a decreased rate of pentobarBital metabolism in vivo.
TL;DR: It can be shown that optimal chlorination may occur between pH 4.0 and 7.4, and it may be concluded that the optimal pH for chlori-nation is dependent on the [H2O2]/[C1-] ratio.
Abstract: SummaryThe oxidation of Cl- ion by H2O2 yielding Cl+ is catalyzed by myelope-roxidase (MPO) prepared from human PMN. Both H2O2 and CI- in this reaction serve as substrates. Affinity (apparent) studies between MPO and CI- and MPO and H2O2 were carried out. Both (apparent) affinities vary according to pH. The higher the pH, the less the affinity for Cl-. In contrast, the affinity between MPO and H2O2 increases with pH. The dissociation constant of the MPO-CI- enzyme substrate complex is affected by the second substrate, H2O2. The effect of H2O2 on the MPO-C1- affinity is competitive. Likewise, the MPO-H2O2 affinity is decreased with increasing Cl- concentration. This influence is also competitive. From these interactions, it may be concluded that the optimal pH for chlori-nation is dependent on the [H2O2]/[C1-] ratio. The relationship of pH, H2O2, and CI- concentrations may be expressed by the following formula: pH = log [CI-] x560/ [H2O2]. Using the formula, it can be shown that optimal chlorination may oc...
TL;DR: Temperature-sensitive mutants of simian virus isolated following nitrous acid or hydroxylamine mutagenesis demonstrated two patterns of expression of virion antigens, which were indistinguishable from wild type on the basis of antigenic phenotype.
TL;DR: In this article, a linear stability analysis for flow between concentric cylinders when a fully developed axial flow is present is presented, where small perturbations are assumed to be nonaxisymmetric.
Abstract: A linear stability analysis is presented for flow between concentric cylinders when a fully developed axial flow is present. Small perturbations are assumed to be nonaxisymmetric. This leads to an eigenvalue problem with four eigenvalues: the critical Taylor number, an amplification factor and two wavenumbers. The presence of the tangential wavenumber permits prediction of the stability of spiral flow. This made it possible to model the flow more accurately and to extend the range of calculations to higher axial Reynolds numbers than had previously been attainable. Calculations were carried out for radius ratios from 0·95 to 0·1, Reynolds numbers as large as 300 and cases with co-rotation and counter-rotation of the cylinders.
TL;DR: Newer lung function tests (e.g., flow volume-loops and closing volume), as well as standard pulmonary function tests, were performed on 19 healthy individuals in the third trimester and after delivery and found that the flow characteristics, manifested in the FVL, and the CV remained unaltered during pregnancy.
TL;DR: SDS polyacrylamide gel electrophoresis of nonreduced and reduced fibrinogen and its derivatives indicates that the intact fibr inogen molecule is essential for ADP-induced platelet aggregation.
TL;DR: In this paper, the authors measured the light emission arising from the H2O2/OCI- reaction and found that certain cyclic diamines increase the emission of light, while other amines were inhibitory.
Abstract: — Various nitrogen containing compounds have previously been shown to quench singlet oxygen (10z). When measuring the dimol 1O2 light emission arising from the H2O2/OCI- reaction, we found that certain cyclic diamines increase the emission of light, while other amines were inhibitory. This increase of light emission was seen with both 1, 4diazabicyclo[2.2.2]octane and N, N'-dimethylpi-perazine but not with acyclic analogues. Sodium azide inhibited both the normal and enhanced light emission. The enhanced light emission shows spectral properties characteristic of lO2 dimol emission.
TL;DR: The presence of a 5' terminal pppAp structure in each RNA segment confirms indications from electron microscopy that the apparently circular RNA segments are not covalently closed, and supports the concept that Uukuniemi virus is a negative strand virus.
TL;DR: To determine whether extrahypothalamic brain TRH arises from the hypothalamus or is synthesised in situ, electrolytic lesions of the “thyrotrophic area” of the rat hypothalamus are made and the effect on TRH content is examined, finding that such lesions markedly reduce the hypothalamic content of TRH, deplete the pituitary gland ofTRH and result in severe chemical hypothyroidism.
Abstract: THYROTROPHIN-releasing hormone (TRH) is widely distributed in regions of the brain outside the hypothalamus1–3, and behavioural4 and neurophysiological5 studies lend credence to the hypothesis1,6 that in these locations it is involved in neuro-transmission. To determine whether extrahypothalamic brain TRH arises from the hypothalamus or is synthesised in situ, we have made electrolytic lesions of the “thyrotrophic area”7 of the rat hypothalamus, and examined the effect on TRH content in the hypothalamus itself, the rest of the brain and the anterior and posterior pituitary. We have found that such lesions markedly reduce the hypothalamic content of TRH, deplete the pituitary gland of TRH and result in severe chemical hypothyroidism, but do not affect the large amount of TRH normally stored in the extrahypothalamic brain.