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Showing papers by "Johns Hopkins University School of Medicine published in 1972"



Journal ArticleDOI
TL;DR: The uptakes of glutamic and aspartic acids were mutually competitive in both cerebral cortical and spinal cord preparations, suggesting that they utilize the same uptake mechanism.

465 citations


Journal ArticleDOI
TL;DR: The ability to measure this new pituitary polypeptide by radioimmunoassay permits investigation of its role in human gestation and during the menstrual cycle.

388 citations


Journal ArticleDOI
10 Nov 1972-Science
TL;DR: The high-affinity choline uptake appears to represent selective choline accumulation by cholinergic neurons, and is associated with considerable formation of acetylcholine.
Abstract: Synaptosomes from rat brain accumulate choline by two kinetically distinct processes, a high-affinity uptake system [Michaelis constant (K(m)) = 1 x 10(-6)M], and a low-affinity system (K(m) = 9 x 10(-5)M). The high-affinity uptake system requires sodium, and is associated with considerable formation of acetylcholine. The low-affinity uptake system is less dependent on sodium, and does not appear to be associated with a marked degree of acetylcholine formation. The high-affinity choline uptake appears to represent selective choline accumulation by cholinergic neurons.

285 citations


Journal ArticleDOI
TL;DR: Virus-like particles resembling papovaviruses in the brain of one patient and in monkey-kidney cell cultures infected with both virus isolates indicate a close relation between the isolated viruses and SV40.
Abstract: Virus related to simian-virus 40 (SV40) was isolated from brains of two patients with progressive multifocal leukoencephalopathy, a human demyelinating disease. Virus was grown in cell cultures of primary African green-monkey kidney inoculated with cultures of cells derived from patients' brains. Electron microscopy showed virus-like particles resembling papovaviruses in the brain of one patient and in monkey-kidney cell cultures infected with both virus isolates. Immunologic studies using fluorescent and neutralizing antibodies indicate a close relation between the isolated viruses and SV40.

284 citations


Journal ArticleDOI
TL;DR: The results argue strongly for the exclusive localization of the receptor to the cell surface by showing that intracellular membranes or particles have no significant and specific insulin-binding activity.

276 citations


Journal ArticleDOI
TL;DR: A new, behavioral model which employs mothers' health motivations, perceptions, and attitudes as predictors of giving oral penicillin and keeping follow-up appointments for otitis media is tested.

237 citations


Journal ArticleDOI
25 Feb 1972-Science
TL;DR: Direct effects of insulin on an enzymatic system in broken-cell -preparations suggest a fundamental role of adenylate cyclase activity and of cyclic adenosine monophosphate in the mechanism of action of insulin.
Abstract: Insulin depresses both the activity of adenylate cyclase stimulated by glucagon, epinephrine, and sodium fluoride in liver cell membranes and the activity of adenylate cyclase stimulated by epinephrine and adrenocorticotropin in particulate preparations from homogenates of isolated fat cells. Significant inhibition is detected with very low concentrations (10 -11 molar) of insulin but not with unphysiologically high (10 -9 molar) concentrations of the hormone. These direct effects of insulin on an enzymatic system in broken-cell -preparations suggest a fundamental role of adenylate cyclase activity and of cyclic adenosine monophosphate in the mechanism of action of insulin.

226 citations



Journal ArticleDOI
TL;DR: The persistence of normal IPTH concentration despite elevated serum total and ionized calcium values suggests an abnormality of the receptor mechanism for the calcium ion control of the secretion of parathormone by the parathyroid glands.

219 citations


Journal ArticleDOI
TL;DR: Review of available data suggests there is a wide spectrum of the disease which may be divided into two main types designated I and II, and aortic incompetence is likely to increase or develop following operation in both types.
Abstract: Twenty-five patients with discrete subaortic stenosis were reviewed. Twenty were operated on for severe obstruction. Review of available data suggests there is a wide spectrum of the disease which may be divided into two main types designated I and II. Type I is a thin discrete membrane immediately under the aortic valve obstructing the outflow but not associated with narrowing of it. Type II is situated about 1 cm below the valve and consists of a fibrous ring, thicker than type I, and associated with muscular hypertrophy which narrows the outflow tract, encroaches on the anterior leaflet of the mitral valve, and may extend 1-2 cm downward. Both have a characteristic angiographic appearance. Results of surgery are good for type I but not satisfactory for type II. Aortic incompetence is likely to increase or develop following operation in both types.


Journal ArticleDOI
TL;DR: Observations revealed that contrary to previous accepted hypotheses, LUV rays have a striking augmentative effect on sunburn damage and an effect on DNA metabolism does occur.

Journal ArticleDOI
TL;DR: APMPPE is considered one of the “placoid diseases” together with serpiginous choroiditis (SC), relentless placoid chorioretinitis, and persistent placoid maculopathy due to the ” placoid” nature of the lesions and similarities on fluorescein angiography (FA) and indocyanine green ang iography (ICGA) findings.

Journal ArticleDOI
TL;DR: The case histories of 9 autistic children, 8 boys and 1 girl, selected from a total of 96 so diagnosed at The John Hopkins Hospital prior to 1953, are presented in some detail and discussed.
Abstract: The case histories of 9 autistic children, 8 boys and 1 girl, selected from a total of 96 so diagnosed at The John Hopkins Hospital prior to 1953, are presented in some detail and discussed. These children, first evaluated and given the diagnosis at an age ranging from 2 years and 10 months to 8 years and 1 month, are presently in their 20's and 30's. Their development is traced from acute psychotic infancy until the end of 1971. Having made a sufficient social adjustment, they manage to function as self-dependent individuals, mostly well educated and all gainfully employed. Attention is drawn to differences between this group and other autistic patients, maturational and environmental issues as well as to past and present patterns of behavior and personality structure.

Journal ArticleDOI
05 May 1972-Science
TL;DR: Electrical stimulation was applied continuously to the denervated rat diaphragm in vivo to mimic the normal activity pattern, and found that muscle activity may account for "neurotrophic" regulation of the acetylcholine sensitivity.
Abstract: Denervation of skeletal muscle results in a spread of acetylcholine sensitivity over the entire surface membrane. Electrical stimulation, programmed to mimic the normal activity pattern, was applied continuously to the denervated rat diaphragm in vivo. After 4 days, the acetylcholine sensitivity was far less in the stimulated diaphragms than in denervated controls. Muscle activity may account for "neurotrophic" regulation of the acetylcholine sensitivity.

Journal ArticleDOI
TL;DR: It is postulated that the disorder is one of impaired coronary perfusion to portions of the right and left ventricular myocardium through increased work demands created by unusually brisk pulmonary vasoconstriction from hypoxia.

Journal ArticleDOI
TL;DR: Age has frequently been used as an experimental variable in investigations of the host determinants of encephalitis and implicated the development of anatomic barriers of resistant cells, maturational changes in the reticuloendothelial system, acceleration of immune responses, and enhanced production of interferon in the limitation of the spread of virus into the adult nervous system.
Abstract: Resistance to Sindbis-virus encephalitis was studied in mice of various ages. Resistance developed abruptly during the second week of life in mice that received either intracerebral or subcutaneous inoculation. In weanling mice, limited replication of virus occurred in the inoculated tissues, and staining with fluorescent antibody showed that the same types of cells became infected in weanlings as in newborns. In weanling mice, infection did not spread; this limitation of viral replication and dissemination was evident by 24 hr. The development of neutralizing antibody at three days and of mononuclear cell infiltrates at four to five days did not appear to determine resistance. Furthermore, fibroblasts from weanling mice were grown in vitro and were found to be resistant to infection, whereas fibroblasts derived from newborn mice were susceptible. In viral infections of man and animals, resistance to disease often develops with increasing age [1, 2]. However, experimental studies of viruses that cause acute encephalitis have shown that the maturing host animal usually remains susceptible to intracerebral infection, while it develops resistance to encephalitis after extraneural inoculation [3-8]. For this reason, age has frequently been used as an experimental variable in investigations of the host determinants of encephalitis. Such investigations have implicated the development of anatomic barriers of resistant cells [4], maturational changes in the reticuloendothelial system [9, 10], acceleration of immune responses [11, 12], and enhanced production of interferon [13] in the limitation of the spread of virus into the adult nervous system. Sindbis virus, a group A arbovirus, causes acute encephalitis in newborn mice after either

Journal ArticleDOI
01 Dec 1972-Science
TL;DR: Observations suggest that glutamate and aspartic acids and glycine serve specific synaptic functions, presumably as neurotransmitters in central nervous tissue.
Abstract: Glutamic and aspartic acids and glycine are accumulated by high-affinity uptake systems into synaptosomal preparations in central nervous tissue. Sodium is required by these high-affinity transports, but not by the low-affinity transports for these and other amino acids. The sodium-requiring amino acid uptake systems label unique synaptosomal fractions. Observations suggest that these amino acids serve specific synaptic functions, presumably as neurotransmitters.


Journal ArticleDOI
08 Sep 1972-Science
TL;DR: Radioimmunoassayable prolactin rises in postpartum women during nursing and after intravenous thyrotropin-releasing hormone (TRH), and the maintenance of a regular nursing pattern seems to promote thetenance of ovarian unresponsiveness to circulating gonadotropins.
Abstract: Radioimmunoassayable prolactin rises in postpartum women during nursing and after intravenous thyrotropin-releasing hormone (TRH). Prolactin release induced by TRH can be dissociated from the postsuckling response. In addition to this, increases in endogenous prolactin secretion are followed by marked breast engorgement and milk letdown, especially after intravenous TRH. In this group of breast-feeding women, vaginal smears remained atrophic even up to 410 postpartum days. Prolactin appears to influence the production of breast milk, and the maintenance of a regular nursing pattern seems to promote the maintenance of ovarian unresponsiveness to circulating gonadotropins.

Journal ArticleDOI
TL;DR: This article presents an analysis in terms of this conceptual system of present knowledge concerning one level of living system—the organization of General systems behavior theory, concerned with seven levels of living systems—cell, organ, organism, group, organization, society, and supranational system.
Abstract: General systems behavior theory is concerned with seven levels of living systems—cell, organ, organism, group, organization, society, and supranational system. An exposition of the basic concepts in this theory appeared in “Living Systems: Basic Concepts,” Behavioral Science, 1965, 10, 193–237. (See also “Living Systems: Structure and Process,” and “Living Systems: Cross-Level Hypotheses,” Behavorial Science, 1965, 10, 337–411.) A condensation of the basic concepts also appeared in “The Nature of Living Systems,” Behavorial Science, 1971, 16, 277–301. The following is an analysis in terms of this conceptual system of present knowledge concerning one level of living system—the organization. In order to emphasize the cross-level formal identities among levels of living systems, this article follows exactly the same outline as other articles written by the author on the cell (“Living Systems. II. The Cell,” Currents in Modern Biology, 1971, 4, 78–206), the organ (“Living Systems. III. The Organ,” Currents in Modern Biology, 1971, 4, 207–254), the organism, and the group (“Living Systems: The Group,” Behavorial Science, 1971, 16, 302–398). Their subheadings and section numbers are identical. All these articles will also be published as chapters of the author's forthcoming book Living Systems (New York: John Wiley & Sons, 1972). Other chapters in that book, also following the same outline, analyze current knowledge about higher levels of living systems—society and supranational system. Since anatomists and physiologists are usually laymen in organization theory or international relations, psychologists are commonly laymen in economics, and social scientists are ordinarily laymen in cellular biology, all parts of the book, including the article published here, are necessarily written for intelligent laymen rather than experts, even though the articles deal with many technical topics. Some statements in them will seem to experts to be too elementary to be worth repeating. If a fact is fundamental and may not be known to specialists in other fields, it is stated here, even if it is elementary to the experts. The complex division of labor of modern science, often characterized by pluralistic insularity, requires this. The multitude of detailed and specialized experiments and studies that have been carried out provide the substance of the scientific investigation of organizations. Their findings constitute the trees. But an overview of these results and of the relationships among them—a view of the forest—is also essential. Such a telescopic rather than a microscopic view may suggest the proper balance for research on various aspects of organizations and clarify the priorities for future efforts. Many ideas presented here are not original with the author, though the arrangement is. Unless several persons have wrestled with an idea it is not often fundamental. The author has necessarily selected only a few researches to discuss out of the vast published repertoire, and so his selection has necessarily been arbitrary. Experts in each special field might agree on other studies as more important. Some of the author's statements may be wrong and his analysis ill advised. If so he would appreciate corrections—it is hard to cover such a wide range and still make no errors. The discussion of the processes of each subsystem ends with a number of examples of the variables of that subsystem which can be observed and measured. These variables make concrete the content of science at this level. They appear also to be common for a particular subsystem at multiple levels of living systems. Measurement of these variables, therefore, can be one way to determine whether cross-level formal identities exist. Throughout the text there are numerous references to cross-level hypotheses. These are mentioned for a similar purpose—to show that propositions possibly valid at other levels may also apply to organizations. These hypotheses, numbered to indicate the section of the article to which they apply, appear on pages 2–5. Many of them have been shown in other articles to be relevant to other levels of living systems as well. At each level there are scientists who apply systems theory in their investigations. They are system theorists but not necessarily general systems theorists. They are general systems theorists only if they accept the more daring and controversial position that though every living system and every level is obviously unique-there are important formal identities of large generality across levels. These can potentially be evaluated quantitatively, applying the same model to data collected at two or more levels. This possibility is the chief reason why the author has used the same outline with identically numbered sections to analyze the present knowledge about each of the seven levels of living systems. The following survey of what is known about organizations as systems, therefore, is to be read as a single segment of a larger, integrated whole.

Journal ArticleDOI
TL;DR: It is suggested that a portion of mouse brain histamine turns over quite rapidly, and the rate of histamine decline reflects the rateof histamine turnover, and these results suggest that the portion of mice brain histamines turns overquite rapidly.
Abstract: — The intraperitoneal administration of L-histidine in a dose of 1000 mg/kg increased threefold the whole brain levels of histamine in the mouse. This increase was evident in all brain regions except the medulla oblongata-pons. The subcellular localization of histamine and histidine was the same in mice administered bhistidine as in salinetreated animals. Cold exposure and restraint further augmented the elevation of histamine elicited by histidine treatment. a-Hydrazino-histidine and 4-bromo-3-hydroxybenzyloxyamine (NSD-1055) but not a-methyl-DOPA inhibited histidine decarboxylase [EC 4.1.1.221 activity in mouse brain homogenates and prevented the increase in brain histamine after histidine administration. NSD-1055 and a-hydrazino-histidine also lowered brain levels of histamine by 50 per cent. NSD-1055 lowered whole brain levels of histamine rapidly, with a half-life for the depletable histamine pool of about 5 min. Assuming that inhibition of histidine decarboxylase accounted for the reduction in histamine, then the rate of histamine decline reflects the rate of histamine turnover, and our results suggest that a portion of mouse brain histamine turns over quite rapidly. Reserpine lowered brain levels of histamine by about 50 per cent, whereas the antihistaminic agent, dexbrompheniramine, and sodium pentobarbital elevated histamine levels.


Journal ArticleDOI
TL;DR: The acid perfusion test and pH probe correlated most closely with symptoms of gastroesophageal reflux while the resting lower esophageAL sphincter pressure and acid barium swallows correlated less well.

Journal ArticleDOI
TL;DR: It is suggested that enhanced photosensitivity of post Synaptic activity is a result of summation of many receptors onto the postsynaptic elements, and that transients in the post synaptic responses are related to the complex synaptic arrangements in the ocellar plexus to be described in the following paper.
Abstract: Intracellular responses from receptors and postsynaptic units have been recorded in the median ocellus of the dragonfly. The receptors respond to light with a graded, depolarizing potential and a single, tetrodotoxin-sensitive impulse at "on." The postsynaptic units (ocellar nerve dendrites) hyperpolarize during illumination and show a transient, depolarizing response at "off." The light-evoked slow potential responses of the postsynaptic units are not altered by the application of tetrodotoxin to the ocellus. It appears, therefore, that the graded receptor potential, which survives the application of tetrodotoxin, is responsible for mediating synaptic transmission in the ocellus. Comparison of pre- and postsynaptic slow potential activity shows (a) longer latencies in postsynaptic units by 5–20 msec, (b) enhanced photosensitivity in postsynaptic units by 1–2 log units, and (c) more transient responses in postsynaptic units. It is suggested that enhanced photosensitivity of postsynaptic activity is a result of summation of many receptors onto the postsynaptic elements, and that transients in the postsynaptic responses are related to the complex synaptic arrangements in the ocellar plexus to be described in the following paper.


Journal ArticleDOI
TL;DR: Cell wall and membrane subfractions of the cell envelope of Escherichia coli have been isolated by a procedure involving particle electrophoresis and sucrose gradient density centrifugation and fatty acid analysis revealed that the wall phospholipids contain a greater proportion of palmitic acid.
Abstract: Cell wall and membrane subfractions of the cell envelope of Escherichia coli have been isolated by a procedure involving particle electrophoresis and sucrose gradient density centrifugation. The lipid content of each fraction has been investigated. The individual phospholipids of both fractions are quantitatively similar except that the proportion of lysophosphatidylethanolamine is greater in the wall than in the membrane. Fatty acid analysis of the phospholipids of each fraction revealed that the wall phospholipids contain a greater proportion of palmitic acid. Coenzyme Q is almost exclusively localized in the cell membrane.

Journal ArticleDOI
01 Dec 1972-Blood
TL;DR: Tryptic peptides characteristic of mouse hemoglobin α- and diffuse-type β-chains were isolated from dimethylsulfoxide-treated mouse leukemia virus-infected cell cultures, reflecting a synthetic capacity that is probably sufficient for 32P labeling of hemoglobin messenger RNAs (mRNA) in quantities commensurate with structural characterization of mRNAs by radioautographic methods.

Journal ArticleDOI
TL;DR: This study demonstrated the acquisition of resistant gram-negative organisms by patients receiving antibiotics within a hospital environment, and implicates transferable episomes as mediators of antibiotic resistance in a significant proportion of these organisms.