Showing papers by "Johns Hopkins University published in 1977"
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01 Jan 1977
TL;DR: It now appears possible to identify these circuits, localize the sites of memory storage, and analyze the cellular and molecular mechanisms of memory.
Abstract: How the brain codes, stores, and retrieves memories is among the most important and baffling questions in science. The uniqueness of each human being is due largely to the memory store—the biological residue of memory from a lifetime of experience. The cellular basis of this ability to learn can be traced to simpler organisms. In the past generation, understanding of the biological basis of learning and memory has undergone a revolution. It is clear that various forms and aspects of learning and memory involve particular systems, networks, and circuits in the brain, and it now appears possible to identify these circuits, localize the sites of memory storage, and analyze the cellular and molecular mechanisms of memory.
1,248 citations
TL;DR: Correlation with phenotype and other known Y chromosome markers establish that the Y-chromosome-specific reiterated DNA discussed here has no evident role in male determination.
Abstract: A number of individuals with aberrant Y chromosomes have been tested for the presence of Y-chromosome-specific reiterated DNA. These studies locate Y-chromosome-specific reiterated sequences on the long arm of the Y chromosome. Correlation with phenotype and other known Y chromosome markers establish that the Y-chromosome-specific reiterated DNA discussed here has no evident role in male determination.
1,206 citations
TL;DR: The proportion of adults with poor "best" visual acuity may be much less than has been estimated by the National Health Survey and the proportion with open-angle glaucoma much more than currently suspected on the basis of foreign studies.
Abstract: During the period 1973--1975, 2675 out of 3977 still-living members of the Framingham, Massachusetts, study population, who have been under investigation for coronary disease risk factors since 1948 and who were in 1973--1975 aged 52 to 85, were given an eye examination stressing cataract, diabetic retinopathy, macular degeneration and glaucoma. Of 2940 subjects who still lived in the local Framingham area, 2477 were examined. Local population prevalence for one or both eyes positive was: 15.5% for senile cataract, 3.1% for diabetic retinopathy, 8.8% for senile macular degeneration and 3.3% for open-angle glaucoma. The proportion of adults with poor "best" visual acuity may be much less than has been estimated by the National Health Survey and the proportion with open-angle glaucoma much more than currently suspected on the basis of foreign studies.
784 citations
TL;DR: The probability of having symptoms of depression was highest among persons who were young adults, unmarried, not employed outside the home, poorly paid, and not well educated.
Abstract: Histories of depression-related symptoms were obtained from 3845 randomly selected adult residents of Kansas City, Missouri, and Washington County, Maryland. Depressed persons were slightly more common in Kansas City than in Washington County but within the latter area no urban–rural differences were observed. More depressed persons were found among blacks than among whites. Slightly more white females than males were depressed; no significant differences were found between black females and males. After adjustment for the effects of other independent variables, the probability of having symptoms of depression was highest among persons who were young adults, unmarried, not employed outside the home, poorly paid, and not well educated.
712 citations
TL;DR: These investigations demonstrate that both lactulose and neomycin-sorbitol are effective in the treatment of chronic portal-systemic encephalopathy.
664 citations
TL;DR: Hematologic data showed derangements associated with intravascular coagulation, the most prominent of which were hypofibrinogenemia and thrombocytopenia, and abnormalities included prolonged prothrombin time, increased fibr inogen-fibrin degradation products, decreased levels of factors V and VIII, cryofibrInogenemia, and microangiopathic hemolytic anemia.
653 citations
TL;DR: The distribution of opiate receptors, determined by the autoradiographic localization of stereospecific [3H]diprenorphine binding sites, was studied in the brain stem and associations of some receptors with small diameter axons, pupillary reflexes, hormonal control, and effects of opiates on neurotransmitter systems were discussed.
601 citations
TL;DR: In certain regions enkephalin immunofluorescence corresponds closely with the distribution of autoradiographic opiate receptor grains.
Abstract: Using specific antisera to methionine-enkephalin and leucine-enkephalin, we have visualized apparent enkephalin-containing neuronal fibers and terminals throughout the central nervous system of the rat. Immunoreactive enkephalin displays sharply defined localizations. Regions of highest immunofluorescent density include the laminae I and II of the spinal cord, the substantia gelatinosa of the caudal nucleus of nerve V, the vagal nuclei of the medulla, the periventricular and periaqueductal areas of the upper medulla and midbrain, dorsomedial thalamic regions, specific hypothalamic nuclei, the basal ganglia, particularly the globus pallidus and the central nucleus of the amygdala, and the lateral septum. In certain regions enkephalin immunofluorescence corresponds closely with the distribution of autoradiographic opiate receptor grains.
574 citations
TL;DR: The presence of cytochrome oxidase activity in the isolated nuclear matrix indicates that at least some integral proteins of the nuclear membrane are associated with the matrix, suggesting that the major matrix polypeptides are localized in specific structural regions of the nucleus.
Abstract: A nuclear framework structure termed the nuclear matrix has been isolated and characterized. This matrix forms the major residual structure of isolated nuclei and consists largely of protein with smaller amounts of RNA, DNA, carbohydrate, and phospholipid. The nuclear matrix can be further resolved by combined treatment with DNase and RNase. The remaining nuclear protein structure, after extraction of 90 percent of the nuclear protein, 99.9 percent of the DNA, and 98 percent of the RNA and phospholipid, is termed the nuclear protein matrix. Electron microscopy of this final nuclear protein matrix reveals an interior framework structure composed of residual nucleolar structures associated with a granular and fibrous internal matrix structure. The internal matrix framework is derived from the interchromatinic structures of the nucleus, and is connected to a surrounding residual nuclear envelope layer containing residual nuclear pore complex structures. Sodium dodecyl sulfate-acrylamide gel electrophoresis of the nuclear matrix proteins demonstrates three major polypeptide fractions, P-1, P-2, and P-3, with average molecular weights of approximately 69,000, 66,000 and 62,000, as well as several minor polypeptides which migrate at approximately 50,000 and at higher molecular weights (>100,000). Polypeptides with molecular weights identical to those of P-1, P-2 and P-3 are also components of isolated nuclear envelopes and nucleoli, whereas isolated chromatin contains no detectable matrix polypeptides. This suggests that the major matrix polypeptides are localized in specific structural regions of the nucleus, i.e., nuclear envelope, nucleoli, and interchromatinic structures. The presence of cytochrome oxidase activity in the isolated nuclear matrix indicates that at least some integral proteins of the nuclear membrane are associated with the matrix.
519 citations
TL;DR: Based on current findings in the HIP study, there appears to be strong support for periodic screening at ages 50 years and over with clinical examination and mammography; to justify screening under 50, new information from other studies is required.
Abstract: Results in the breast cancer screening project of the Health Insurance Plan of Greater New York that started the end of 1963 have been updated through December 31, 1975. The HIP study is a randomized trial designed to test whether periodic screening with clinical examination and mammography results in reduced breast cancer mortality among women aged 40–64 years at the start. Study women were offered screening examinations; 65% appeared for initial examinations and a large majority of these women had at least one of the three additional screenings at annual intervals. The control group of women continued to receive their usual medical care. New data support earlier reported results on benefits. During the nine years following date of entry there were 128 breast cancer deaths in the control group as compared with 91 in the study group (screenees plus refusers). The impact of the screening program continues to be confined to women 50 years of age and over with no benefit at ages 40–49 years. Seven-year case fatality rates show similar relationships. Several issues related to screening benefit are considered. Of major importance is the observation of no reduction among women under 50 in breast cancer mortality. The possibility that under different screening conditions (e.g., with current mammography equipment) a benefit would be found needs to be investigated. There is a clear need for rapidly determining whether a new randomized trial is the only way to answer the question and whether experience in the 27 NCI-ACS demonstration projects can provide useful data. Another critical issue concerns the incremental value of mammography in a screening program. Over an eight-year period after diagnosis, breast cancer cases that were positive only on mammography when screened had a case fatality rate of 14%; this compares with 32% for cases positive only in the clinical examination and 41% for cases positive on both modalities. Excluding mammography would have reduced the benefit of screening by an estimated one-third. With regard to risk associated with screening, it is concluded that the increment in risk resulting from radiation exposure in mammography does not offset the benefits of screening above 50 years of age. Below that age, although the risk increment is small, the risk-benefit balance is negative because of the absence of a demonstrated benefit. Another source of risk is related to the possible increase in biopsies. Assessment of the HIP experience suggests that only timing of biopsies was affected, but the potential for considerable variation if screening is adopted widely exists. Based on current findings in the HIP study, there appears to be strong support for periodic screening at ages 50 years and over with clinical examination and mammography; to justify screening under 50, new information from other studies is required.
515 citations
Journal Article•
TL;DR: A nuclear matrix structure termed the nuclear matrix has been isolated and characterized in this article, which consists largely of protein with smaller amounts of RNA, DNA, carbohydrate, and phospholipid.
Abstract: A nuclear framework structure termed the nuclear matrix has been isolated and characterized. This matrix forms the major residual structure of isolated nuclei and consists largely of protein with smaller amounts of RNA, DNA, carbohydrate, and phospholipid. The nuclear matrix can be further resolved by combined treatment with DNase and RNase. The remaining nuclear protein structure, after extraction of 90 percent of the nuclear protein, 99.9 percent of the DNA, and 98 percent of the RNA and phospholipid, is termed the nuclear protein matrix. Electron microscopy of this final nuclear protein matrix reveals an interior framework structure composed of residual nucleolar structures associated with a granular and fibrous internal matrix structure. The internal matrix framework is derived from the interchromatinic structures of the nucleus, and is connected to a surrounding residual nuclear envelope layer containing residual nuclear pore complex structures. Sodium dodecyl sulfate-acrylamide gel electrophoresis of the nuclear matrix proteins demonstrates three major polypeptide fractions, P-1, P-2, and P-3, with average molecular weights of approximately 69,000, 66,000 and 62,000, as well as several minor polypeptides which migrate at approximately 50,000 and at higher molecular weights (>100,000). Polypeptides with molecular weights identical to those of P-1, P-2 and P-3 are also components of isolated nuclear envelopes and nucleoli, whereas isolated chromatin contains no detectable matrix polypeptides. This suggests that the major matrix polypeptides are localized in specific structural regions of the nucleus, i.e., nuclear envelope, nucleoli, and interchromatinic structures. The presence of cytochrome oxidase activity in the isolated nuclear matrix indicates that at least some integral proteins of the nuclear membrane are associated with the matrix.
TL;DR: In this paper, the authors used a relative preference index to evaluate the phytoplankton preference for NH4+ and urea N over NO, and found that NH 4+ was preferred by the majority of the organisms.
Abstract: Eight stations in the main body of Chesapeake Bay and one on the continental shelf were sampled seven times over a period of 13 months to investigate the nitrogenous nutrition of the phytoplankton. The rates at which the phytoplankton were utilizing NO,, NO,, NHr+, and urea N were determined. The data demonstrate that for a large portion of the year there is inadequate N nutrient available to permit a single doubling of the particulate N. Over temperatures from 4” -28°C and salinities from 2-32&, there was a universally high phytoplankton preference for NH4+ and urea N over NO,and NO,. A relative preference index indicated that NHa’ concentrations in excess of O-5-1.0 pg-atom N liter-l almost totally suppressed NO, utilization. Urea N was used after NH,+ in order of prcfcrence, and when the sum of available NH4+ and urea N was insufficient to meet the phytoplankton N nutrient demand, NO; was used. When the sum of all available N nutrients was less than that required to satiate the phytoplankton demand, NIL’, urea N, NO,-, and NO,were all utilized at rates proportional to their availability. For the midbay region in October 1973, NO, was the dominant N nutrient present both in the water and in the diet of the phytoplankton. The Chesapeake Bay and its tributaries receive nitrogen in discharges of treated sewage from metropolitan areas of the District of Columbia and Baltimore at rates excceding 10 and 7 tonnes d-l. Carpenter et al. (1969) observed high levels of NOS(30100 pg-atoms N liter-l) in the open waters of the north half of the bay during winter and spring, levels undoubtedly sufficient to meet the nutritional needs of the indigenous phytoplankton. The persistence of such levels for several weeks in spring suggests that the rates of supply and loss were approximately balanced during this period. In summer and early autumn the NOs-concentration fell to
TL;DR: Both the blastogenic activity of concanavalin A or lipopolysaccharide and the ability of immune lymphocytes to lyse P815 target cells showed the same patterns of immunosuppression and enhancement.
Abstract: After mice were exposed to a daily auditory stressor for varying lengths of time, the responses of their splenic lymphoid cells in vitro were assessed. Both the blastogenic activity of concanavalin A or lipopolysaccharide and the ability of immune lymphocytes to lyse P815 target cells showed the same patterns of immunosuppression and enhancement.
TL;DR: Exercise thallium-201 MPI is a useful adjunct to conventional exercise testing particularly when evaluating patients with abnormal resting ECGs, those who develop ventricular conduction defects or arrhythmias during exercise, and those who fail to achieve their predicted heart rate because of fatigue or breathlessness.
Abstract: The sensitivity of myocardial perfusion imaging (MPI) using thallium-201 injected both at rest and during peak exercise was compared to simultaneously recorded 12 lead electrocardiography (ECG) for the detection of transient ischemia in 20 normal subjects and 63 patients with coronary artery disease (CAD). No significant perfusion defects or ECG changes were seen on either the rest or exercise studies in any of the normal subjects. Fifty-six percent of patients with CAD developed new perfusion defects with exercise compared to 38% who developed ischemic ST-segment depression (P less than 0.02). However, when chest pain and/or ST depression were considered indices of ischemia, the sensitivity of exercise testing and thallium-201 MPI was similar. The increased sensitivity of MPI compared to ST-segment depression on the ECG was due to patients with baseline ECG abnormalities and those who failed to achieve 85% of predicted maximum heart rate with exercise. Analysis of the exercise results according to the extent of coronary artery disease revealed a progressive increase in both positive ECGs and MPI with the number of vessels involved. In patients with single vessel disease the MPI was more sensitive than the ECG (P less than 0.02). The combination of the rest and exercise ECG, MPI and chest pain during exercise failed to identify 11% of patients with CAD. Exercise thallium-201 MPI is a useful adjunct to conventional exercise testing particularly when evaluating patients with abnormal resting ECGs, those who develop ventricular conduction defects of arrhythmias during exercise, and those who fail to achieve their predicted heart rate because of fatigue or breathlessness.
TL;DR: This article reviewed the basic arguments offered by Pylyshyn and others against using imagery as an explanatory construct in psychology and concluded that debate about the ultimate foundations of internal representation is fruitless; the empirical question is whether images have properties that cannot be derived directly from abstract propositional structures.
TL;DR: Preliminary estimates suggest that half of the eyes that lost visual field might demonstrate reproducible abnormalities of the nerve fiber layer between four and six years before onset of their visual field defects.
Abstract: • Serial fundus photographs of 14 eyes that eventually developed glaucomatous visual field defects and 110 slides from 76 eyes of race- and age-matched controls were reviewed in randomized masked fashion. Each eye that lost visual field demonstrated consistent abnormalities of the nerve fiber layer, beginning as early as 5 years (mean, 1½ years) before it developed glaucomatous visual field defects on routine Goldmann perimetry. Preliminary estimates, based on regression analysis of this small series, suggest that half of these eyes (median) might demonstrate such reproducible abnormalities between four and six years before onset of their visual field defects. Only 9% of the matched controls showed similar nerve fiber layer changes, and in the one instance where analysis was possible, these were inconsistent and nonreproducible. Nerve fiber layer assessment by means of fundus photographs may be the earliest, surest means of distinguishing ocular hypertension from true glaucoma. ( Arch Ophthalmol 95:2149-2156, 1977)
TL;DR: Because of the more favorable prognosis of the myxoid variant, it seems appropriate to separate it from the usual nonmyxoid form of MFH, which must also be clearly distinguished from benign myxoids lesions such as myxoma or nodular fasciitis, with which it is often confused.
Abstract: It has been generally recognized that malignant fibrous histiocytoma (MFH) may assume a highly myxoid, hypocellular appearance. Eighty cases of malignant fibrous histiocytoma having varying degrees of myxoid change were reviewed. These tumors typically arose on the extremities (leg, 61%; arm, 21%) of adults (peak age incidence, 60-69 years). They were usually attached to fascia (31%) or involved skeletal muscle (51%) and had a mucoid or translucent appearance. The myxoid areas consisted of widely spaced spindled and pleomorphic cells embedded in a matrix of acid mucopolysaccharides. The cellular areas were indistinguishable from those of the typical pleomorphic MFH. The rate of local recurrence of these tumors was 61%, and of metastasis, 23%, but metastasis was less likely when the tumor was small, superficially located, or had a prominent myxoid component. In fact, the degree of myxoid change was inversely related to the rate of metastasis. Therefore, because of the more favorable prognosis of the myxoid variant, it seems appropriate to separate it from the usual nonmyxoid form of MFH. The myxoid variant must also be clearly distinguished from benign myxoid lesions such as myxoma or nodular fasciitis, with which it is often confused.
TL;DR: The decay curves of r(t) indicates that the orientational motion of DPH in the hydrocarbon region is described by a wobbling diffusion restricted by a certain anisotropic potential.
Abstract: Molecular motions in liposomes of dipalmitoyl- phosphatidylcholine (DPPC) were studied by nanosecond fluorescence techniques. As a fluorescent probe for the hy- drocarbon region, 1,6-diphenyl-1,3,5-hexatriene (DPH) was used. Time courses of fluorescence intensity ZT(t) and emission anisotropy r(t) of DPH embedded in DPPC liposomes were measured at various temperatures. The value of the fluores- cence lifetime 7 obtained from a single exponential decay of Ir(t) was somewhat higher than that in liquid paraffin below the transition temperature TI and decreased above TI. Higher values of 7 below TI, indicate the almost complete hydrophobic environment. The decay curves of r(t) were separated into two phases: an initial fast decreasing phase of the order of one nanosecond and a second almost constant phase. This indicates Structure and dynamics of lipids in biological membranes have been recognized as the essential factors in their functions and organization (Inesi et al., 1973; Racker and Hinkle, 1974). Phospholipids in model membranes such as aqueous disper- sions or liposomes are known to be in a bilayer structure and the cooperative melting of their hydrocarbon chains, the crystalline-liquid-crystalline phase transition, takes place at a certain temperature (Trauble and Eibl, 1974; Sackmann et al., 1973; Chapman, 1975; Jacobson and Papahadjopoulos, 1975). Studies of dynamic properties or molecular motion of lipids in model bilayers, however, have not resolved several important questions. Although the use of spin-label techniques for the dynamic studies of lipid bilayers is widespread, the information re- garding molecular motion is restricted in most investigations. In describing the characteristics of molecular motion of that the orientational motion of DPH in the hydrocarbon re- gion is described by a wobbling diffusion restricted by a certain anisotropic potential. The results were analyzed on the model that the wobbling diffusion is confined in a cone with a uniform diffusion constant. Though temperature dependence of the cone angie was sigmoidal, that of the wobbling diffusion con- stant was like the exponential function. The change in the cone angle at TI was sharper than that in the wobbling diffusion constant at TI. Estimated values of the viscosity in the cone were an order of magnitude smaller than the values of "mi- croviscosity" which were estimated from the steady-state emission anisotropy without considering the restrictions on the rotational motion.
TL;DR: It is concluded that mood disorder is a more specific complication of stroke than simply a response to the motor disability and that a controlled trial of antidepressant medication is indicated for patients with this complication.
Abstract: In an effort to discern whether cerebral vascular injuries provoke specific emotional disturbances, 20 consecutively admitted stroke patients were compared with 10 orthopaedic patients. Both groups were examined for functional disabilities (Activities of Daily Living) and for psychiatric symptoms. Reliable and valid instruments, the Hamilton Rating Scale, the Visual Analogue Mood Scale, the Present State Exam, and the Mini-Mental State Exam were employed to display the psychopathology. More of stroke patients than orthopaedic patients were depressed (45% versus 10%) even though the level of functional disability in both groups were the same. Patients with right hemisphere stroke seemed particularly vulnerable and and displayed a syndrome of irritability, loss of interest, and difficulty in concentration, in addition to depression of mood (70% of right hemisphere stroke patients versus 0% left hemisphere stroke patients and 0% orthopaedic patients). We conclude that mood disorder is a more specific complication of stroke than simply a response to the motor disability. We suggest that a controlled trial of antidepressant medication is indicated for patients with this complication.
TL;DR: The need for corroboration of these findings is stressed, which may be a mix of real and chance associations, and the need for additional analyses before any of these associations are considered evidence of factors related to risk of ophthalmic disease.
Abstract: Using the age-sex-specific data collected in the Framingham Heart Study 1948--1964 together with ophthalmic diagnoses made in the Framingham Eye Study in 1973--1975, the following variables were found to be associated with senile cataract: education, casual blood sugar, systemic blood pressure, height, vital capacity, serum phospholipid and hand strength; with senile macular degeneration: systemic blood pressure, height, vital capacity, left ventricular hypertrophy, hand strength and history of lung infection; with diabetic retinopathy: casual blood sugar, urine sugar and other specific elements of diabetes; with ocular hypertension: systemic blood pressure, height, casual blood sugar and pulse rate. No variables were identified as associated with open-angle glaucoma. The paper stresses the need for corroboration of these findings, which may be a mix of real and chance associations, and the need for additional analyses before any of these associations are considered evidence of factors related to risk of ophthalmic disease.
TL;DR: In this paper, the role of humoral factors in the pathogenesis of myasthenia gravis was investigated using passive transfer of human serum fractions to mice, where the active fraction was identified as IgG by three different purification methods.
Abstract: To study the role of humoral factors in the pathogenesis of myasthenia gravis, we employed passive transfer of human serum fractions to mice. Immunoglobulins from 16 patients with myasthenia gravis were injected into mice daily for one to 14 days. Typical myasthenic features of reduction in amplitude of miniature end-plate potentials (mean change more than 50 per cent, P less than 0.005) or reduction in acetylcholine receptors at neuromuscular junctions (mean change more than 50 per cent, P less than 0.005) (or both) were produced by immunoglobulin from 15 of the 16 patients. Some mice showed weakness or decremental responses to repetitive nerve stimulation as well. The active fraction was identified as IgG by three different purification methods. Its effect was enhanced by the third component (C3) of the complement system, but the fifth component (C5) had no effect. These data suggest that the pathogenesis of myasthenia gravis often involves and antibody-mediated autoimmune attack on the acetylcholine receptors of the neuromuscular junction.
TL;DR: The results suggest that the high glycolytic capacity of H-91 hepatoma cells is due, at least in part, to an elevated form of hexokinase concentrated in the mitochondrial fraction of the cell.
Abstract: A tumorigenic anchorage-dependent cell line (H-91) was established in culture from an azo-dye-induced rat ascites hepatoma. When grown in a glucose-containing medium the cells exhibit high rates of lactic acid production characteristic of rapidly growing tumor cells. However, when glucose is replaced with galactose the cells grow equally well but exhibit only moderately elevated rates of lactic acid production. The molecular basis for this observation cannot be attributed to differences in permeability because initial rates of glucose and galactose entry into hepatoma cells are identical. Rather, the activity of hexokinase (ATP:D-hexose 6-phosphotransferase, EC 2.7.1.1) is found to be high in hepatoma cells, about 20-fold higher than that of control and regenerating rat liver. Moreover, tumor hexokinase activity is not inhibited by low concentrations (<0.6 mM) of the reaction product glucose 6-phosphate. Additionally, 50% of the hexokinase activity of hepatoma cells is found associated with the mitochondrial fraction. This fraction is 3-fold enriched in hexokinase activity relative to the homogenate and 4-fold enriched relative to the nuclear and postmitochondrial fractions. Tumor mitochondrial hexokinase appears to be coupled directly to oxidative phosphorylation, because addition of glucose to respiring hepatoma mitochondria (after a burst of ATP synthesis) results in stimulation of respiration. In contrast, glucose has no effect on the respiration of mitochondria from control and regenerating liver. These results suggest that the high glycolytic capacity of H-91 hepatoma cells is due, at least in part, to an elevated form of hexokinase concentrated in the mitochondrial fraction of the cell.
TL;DR: Two patterns which differed only in a single part could be discriminated from each other more quickly than could their distinguishing parts shown in isolation, and the outlines of a model for preattentive feature discrimination are presented.
Abstract: Theories of visual pattern recognition frequently assume that processing begins with an analysis of the pattern into component parts, which are often assumed to be line segments of particular orientations, lengths, positions, and curvatures. The present experiments measured discriminability of these simple parts when presented either in isolation or within configural contexts that provided no formal information useful for the discrimination. Certain contexts either impaired or did not affect performance. Other contexts were found, however, which dramatically improved discriminability. Thus, two patterns which differed only in a single part could be discriminated from each other more quickly than could their distinguishing parts shown in isolation. Further experiments suggest that this "configural superiority" effect influences perceptual components of processing rather than memorial components. The mechanism underlying configural superiority appears to be the detection of novel and distinguishing features, such as corners and intersections, which emerge when parts are placed in close proximity to each other. The outlines of a model for preattentive feature discrimination are presented.
TL;DR: Several tricyclic antidepressants have been assessed for their potency in binding to the muscarinic acetylcholine receptor of brain and intestine, with implications for their use in patients who might be affected adversely by anticholinergic effects.
Abstract: Several tricyclic antidepressants have been assessed for their potency in binding to the muscarinic acetylcholine receptor of brain and intestine. Amitriptyline hydrochloride is about ten times as potent as imipramine hydrochloride. Dimethylated drugs are more potent than monomethylated ones. The relative anticholinergic activities of tricyclic antidepressants have implications for their use in patients who might be affected adversely by anticholinergic effects.
TL;DR: In this article, rats were tested on an elevated radial maze for their ability to choose each of 17 different arms without repeating any choices, and the results indicated that the animals performed well, choosing an average of more than 14 different arms in the first 17 choices.
TL;DR: Findings indicated subtantial levels of invariance across gender for eight of the nine primary symptom dimensions of the SCL-90 with moderate levels for the ninth.
Abstract: The present study was focused on an evaluation of factorial invariance across gender for the primary symptom dimensions of the SCL-90-a multidimensional self-report symptom inventory. The argument is advanced that evidence of invariance across relevant subject parameters is an essential component of reliability for dimensional constructs. Findings indicated subtantial levels of invariance across gender for eight of the nine primary symptom dimensions of the SCL-90 with moderate levels for the ninth. The implications of invariance, for the SCL-90 in particular, and clinical measurement in general are related and discussed.
01 May 1977
TL;DR: This paper focuses on techniques for detecting and identifying the spikes in multispike trains and a method based on signal detection by template matching, which works well with relativeiy small spikes, is described in detail.
Abstract: Multispike trains are encountered often, either purposely or inadvertently, when one records from neural populations. This paper focuses on techniques for detecting and identifying the spikes in multispike trains. Relatively simple methods are briefly reviewed. Most of these require a high signal-to-noise ratio. A method based on signal detection by template matching, which works well with relativeiy small spikes, is described in detail. Use of this technique is illustrated by an investigation of the biophysical aspects of extracellular recording in sensory cortex. A further application is the analysis of multi-unit records to display relationships between two or three neurons recorded simultaneously.
TL;DR: A thorough understanding of the ways in which the lung protects itself against the daily assault of infectious, toxic, and immunogenic materials should lead to a beter understanding of pathogenesis and consequences of lung disease and to better clinical care of the patient with respiratory disease.
Abstract: The success or failure of pulmonary defense mechanisms largely determines the appearance of clinical lung disease. The lung is protected by interlucking systems of nonspecific and specific defenses. Inhaled substrances can be isolated by mechanical barriers or can be physically removed from the lung either by transport up the bronchial mucociliary escalator or by transport through interstitial and lymphatic channels leading to lymph nodes. Substances can be locally detoxified within the lung by interaction with secretory proteins, such as antibodies, or by neutralization and dissolution within phagocytic cells. The pulmonary alveolar macrophage is the central figure in the protection of the respiratory membrane, operating in all 3 of the nonspecific modes of defense and augmented by specific immunologic mechanisms as well. Alterations in macrophage function and physiology may be crucial in determining the effectiveness of pulmonary defense. Recent advances in the cell biology of the alveolar macrophage have led to a greater understanding of its complex funcition. The multiple origins of macrophages from local and circulating cell pools and the variability in their fate and lifespan reflect the multi-faceted role of this cell type. The importance of the interactions between macrophages, orther lung cells, and other defense mechanisms has become increasingly clear. As well as functioning as resident defender of the alveolus, the macrophage is an important effector of the pulmonary immune response and plays a key role in the pathogenesis of a wide variety of inflammatory, destructive, and fibrotic lung diseases. Humoral and cell-mediated immune responses amplify and direct lung defenses against infection and may also participate in protection against other agents. Immunoglobulin A and G, microbial neutralizing and opsonizing anti-bodies, and macrophage-stimulating T lymphocytes are the major immunospecific forms of lung defense. Infectious agents, cigarette smoke, air pollutants, industrial dusts, and a spectrum of coexistent disease states may impair pulmonary defense mechanisms and increase susceptibility to asute and chronic respiratory diseases. A thorough understanding of the ways in which the lung protects itself against the daily assault of infectious, toxic, and immunogenic materials should lead to a beter understanding of pathogenesis and consequences of lung disease and to better clinical care of the patient with respiratory disease.
TL;DR: Fluorescence is seen in many brain areas, with notable densities in the substantia gelatinosa zones of the spinal cord and trigeminal nucleus, central amygdaloid nucleus, anterior pituitary, median eminence, and preoptic and basal hypothalamic areas.
Abstract: Neurotensin immunofluorescence was examined in the rat central nervous system using a well-characterized antiserum directed against this tridecapeptide. Morphological characteristics of the fluorescence indicate its association with neuronal cell bodies and processes in the brain and with cells of the anterior pituitary. Fluorescence is seen in many brain areas, with notable densities in the substantia gelatinosa zones of the spinal cord and trigeminal nucleus, central amygdaloid nucleus, anterior pituitary, median eminence, and preoptic and basal hypothalamic areas.