Showing papers on "Literature survey published in 1979"

In vivo covalent binding of organic chemicals to DNA as a quantitative indicator in the process of chemical carcinogenesis.

Abstract: The covalent binding of chemical carcinogens to DNA of mammalian organs is expressed per unit dose, and a 'Covalent-Binding Index', CBI, is defined. CBI for various carcinogens span over 6 orders of magnitude. A similar range is observed for the carcinogenic potency in long-term bioassays on carcinogenicity. For the assessment of a risk from exposure to a carcinogen, the total DNA dmaage can be estimated if the actual dose is also accounted for. A detailed description is given for planning and performing a DNA-binding assay. A complete literature survey on DNA binding in vivo (83 compounds) is given with a calculation of CBI, where possible, 153 compounds are listed where a covalent binding to any biological macromolecule has been shown in vivo or in vitro. Recent, so far unpublished findings with aflatoxin M1, macromolecule-bound aflatoxin B1, diethylstilbestrol, and 1,2-epithiobutyronitrile are included. A comparison of CBI for rat-liver DNA with hepatocarcinogenic potency reveals a surprisingly good quantitative correlation. Refinements for a DNA-binding assay are proposed. Possibilites and limitations in the use of DNA binding in chemical carcinogenesis are discussed extensively.

Occurrence of C3 and C4 photosynthetic pathways in North American Grasses.

Abstract: A literature survey was made for the occurrence of C, and C, photosynthetic pathways in the United States Gramineae. Distinctive characteristics of the two photosynthetic pathways are discussed. Leaf anatomy, CO, compensation point, net enhancement of photosynthesis in oxygen-deficient atmosphere, QC discrimination, and initial product labeling were criteria selected to evaluate data for 6 subfamilies including 25 tribes, 138 genera, and 632 species. The Arundinoideae, Bambusoideae, Oryzoideae, and Pooideae (Festucoideae) are composed of species with C, pathways. All tribes within the Eragrostoideae have C, pathways with the exception of Unioleae. Within the Panicoideae, the Andropogoneae and all of the Paniceae, excepting the genera Sacciolepus, Isachne, Oplismenus, Amphicatpum, and Panicum, have C, pathways. The subgenus Dichanthelium within Panicum is C, while the Bupanicum subgenus contains plants with both C, and C, photosynthetic pathways. Plant productivity is dependent on several environmental and biological factors. The most important single factor is photosynthesis. A pathway for carbon dioxide (CO;?) fixation was described by Calvin and Bassham (1962) in which CO2 was incorporated into a 6-carbon compound and rapidly converted to a 3-carbon compound, 3-phosphoglyceric acid (3PGA). Previous to discoveries of Kortschalk et al. (1965) and Hatch and Slack (1966), the Calvin cycle (C,, reductive pentose pathway) was considered the major photosynthetic mechanism for carbon (C) fixation. However, Hatch and Slack (1966) described CO;! fixation in which labeled CO;! was first incorporated in 4-carbon compounds (malic, aspartic , or oxaloacetic acid) prior to transfer to sugars by way of 3-phosphoglycerate. The proposed mechanism involved the operation of two interconnected metabolic cycles. Downton (1970) described carbon fixation into Cd-dicarboxylic acids in mesophyll cells and subsequent incorporation into the Calvin cycle located in the bundle sheath cells. Plants (Cd plants) possessing the 4-carbon pathway (also called Cd, dicarboxylic acid, Kranz type, low CO;! compensation, tropical, Hatch and Slack, or p carboxylation pathway) were of tropical ongm and more efficient. They produced two- to threefold more dry matter than plants possessing the 3-carbon pathway (C, plants), especially in relatively sunny, warm, dry climates (Black 197 1). Distinctive characteristics associated with the Ca pathway prompted intensive research in photosynthetic processes of flowering plants. The most important photosynthetic pathways

Organolead compounds: environmental health aspects.

Abstract: Since 1923 organolead compounds have been used as antiknock additives to gasoline, and few organic chemicals are now produced in greater amounts than organolead. Early cases of poisoning resulted in increased safety precautions, but augmented production and pollution have not been followed by adequate regulations in order to eliminate environmental health hazards. Occupational and environmental exposures to inorganic lead is currently under debate, and the lead standards have recently been lowered in several countries. Organolead compounds are considered much more toxic than the inorganic lead compounds. Recent cases of organolead poisonings, and the discovery of organolead compounds present in brains of people, have questioned the safety of organolead as a gasoline additive. As a result the authors were asked by the Swedish Environmental Protestion Agency to prepare a literature survey on organic lead in 1977. The present review is an updated and extended version of the 1977 survey.

Genome size in angiosperms: temperate versus tropical species

Abstract: The presence of genome size differences between tropical and temperate plants was sought in a literature survey including 368 tropical and 524 temperate herbs. The mean and total chromosome lengths of pairs of chromosome complements of tropical plants are smaller than those properties of temperate plants. The mean length of chromosomes of tropical plants is 3.1 μ compared to 5.6 μ for temperate plants. The total chromosome length of the former assemblage is 61.3 μ versus 105.9 μ for the latter assemblage. The mean diploid number of the plants from each geographical region is near 19. Thus differences in length of chromosome complements are not attributable to numbers of chromosomes. Therefore, in general, genome size is larger in temperate herbs than in tropical ones. A comparison of 4C-DNA contents of species as presented in the literature showed that the genome sizes of temperate species is more than twice that of tropical species. The temperate-tropical differential present in angiosperms as a whole is...

Clay minerals in canadian soils: their origin, distribution and alteration

Abstract: A literature survey was conducted to collect mineralogical data of Canadian soils. In the past 40 years, clay mineralogical data of varying precision have been reported for approximately 1200 samples from more than 380 pedons. Based on the data, (1) the distribution of clay minerals was examined physiographically, (2) an investigation was made to relate specific changes in clay minerals of pedons within a physiographic region to taxonomy, and (3) a comparison was made of the clay mineral alteration in the pedons of the same order in different physiographic regions. The results indicated that virtually no or minor alterations of clay minerals had occurred in pedons of many Canadian soils with the exception of Podzolic soils and to a limited extent, Brunisolic, Luvisolic and Gleysolic soils. In the Podzolic soils, chlorite disappeared or diminished in surface horizons, and micas and possibly some chlorites were transformed by hydration into partially or fully expansible clay minerals. For general soil clay ...

Double Minutes in Human Carcinoma Cell Lines, With Special Reference to Breast Tumors

Abstract: Small DNA-containing particles called double minutes (dm) were observed in metaphases during a survey of human tumor cell lines. Detection of dm in uncultured malignant effusions, in a series of 14 breast carcinoma cell lines, and in a cervical carcinoma cell line, and a literature survey indicated that dm may be more common among human malignant cells than previously suspected. Some of the human breast carcinoma cell lines showed a high incidence of dm, which permitted a series of cytochemical studies. The dm stained identically with euchromatic regions of human chromosomes. Unlike typical chromsomes, dm contained neither C-bands nor Cd bands indicative of paracentromeric heterochromatin and centromeres, respectively. The dm were observed to cluster at the ends of chromosomes, and individual dm adhered to chromosomes. This clustering behavior allows dm to pass through cell division in the absence of centromeric regions. These results should alert tumor cytogeneticists to the possibility that their material may contain a low incidence of undetected dm.

Human Factors in Computer Systems: A Review of the Literature.

Abstract: : Based on an extensive literature survey, this document presents a description and critical analysis of the state of the art in the area of human factors in computer systems This review is concerned both with the status of human factors research in the area of user computer interaction and with the current state of user-computer interaction technology and practices The primary purpose of the review is to determine whether research and practice in this area have evolved sufficiently to support the development of a human factors guide to computer system design It is concluded that insufficient data exist for the development of a 'quantitative reference handbook' in this area, but that a 'human factors design guide' -- which discusses issues, alternatives, and methods in the context of the design process -- is both feasible and needed (Author)

Two Decades of Spacecraft Attitude Control

Abstract: Introduction T HIS paper does not fit into the usual pigeonholes of technical works, so it is necessary to start by telling the reader what it is and what it is not. It is a very personal perspective on spacecraft attitude control since the subject was first formalized in 1957, given by one who has followed it from the beginning. Special emphasis is on the period of concept formation, mainly prior to 1965, and on topics that fall within my own areas of special interests. The paper is obviously not an exhaustive literature survey of attitude control; the archive literature alone, with several thousand items, is simply too vast. Nor has there been any attempt to make the coverage complete, in the usual scholarly sense, even within its restricted scope. Although I have tried to maintain a balanced viewpoint, the reader must recognize that problems are always possible when history is recounted by an active participant. At the end of two decades of space flight it is appropriate to take a retrospective look at some of the major functional ingredients of spacecraft.! Attitude control is one of these. In the classical literature of astronautics it was scarcely recognized as an area worth studying. In 1977 I heard it said that in extreme cases the attitude control subsystem can represent up to 30% of the cost of the spacecraft. This much change in the subject's perceived importance is reason enough to review its evolution over the past two decades. If its role could be so underestimated then, what might have changed in our viewpoint toward the structure of the discipline itself and the methods available to perform the attitude control function? We would hardly expect attitude control to have suddenly emerged as a new discipline exactly 20 years ago, at the time space flight began. On the basis of the published literature, it is not unreasonable to pick 1952 as its nominal birth year. A history of the subject prior to 1952 already has been given , in which it was pointed out that the first systematic study of spacecraft attitude control in its own right began that year. (This study was documented only in unpublished form , i.e., as a company report whose original classification was "Secret".) Some forerunners existed (described in Ref. 1), extending from the technology of spin-stabilized projectiles in the 16th century, through the gyroscopic stabilization proposals in early speculative studies of space flight done in the late 1920's, to several secret studies of spacecraft sponsored by U.S. government agencies (under the euphemism "High Altitude Test Vehicles") in the second half of the 1940's. But as regards the specific subject of attitude control, published work was sparse, neither comprehensive nor intensive, and invariably formed an incidental part of broader system studies. Not until the mid 1950's did a trickle of publications begin in which spacecraft attitude control was the explicit central theme. Gravitational torque on an artificial satellite was the motivation of one work in 1956, although its wording had to be very carefully couched to avoid hinting at such a vehicle. In 1957 another addressed the effect of the Earth's magnetic field on satellite spin. Finally, in 1957 a third described for the first time in the open literature the general problem of actively controlling an artificial satellite so that one of its axes remains pointed downward toward the Earth. In the USSR that same year, Beletskii made two contributions' to problems of "classical type" (see later) having implications to the uncontrolled behavior of artificial satellites. Thus the open, archive publication of works on artificial satellites began at almost exactly the same time as the first space flight (in October, 1957), giving us a double motivation for choosing 1957 as the initial point of the two-decade period with which we are dealing. The purpose of this paper is to give an overview of the attitude control discipline as we see it at the end of 1977, and to put this into perspective with the 1957 viewpoint. Certain subsequent developments could be foreseen fairly well at that time, and these are reviewed. Perhaps more interesting is to identify those unforseen developments which were essentially new to the period. Finally, a few words are ventured about the future. The real substance of the two decades lies, of course, in the attitude control systems themselves, those that actually have been put into space. A review of those and their observed performance would be very appropriate at this time, but this

Failure of Trimethoprim/ Sulfamethoxazole in Invasive Nocardia asteroides Infection

Abstract: A case of pulmonary nocardiosis occurred with progressive involvement of the pleura, pericardium, mediastinum, and sternum. Surgical resection and drainage procedures followed by administration of the drug combination, trimethoprim/sulfamethoxazole, over a six-month period led to clinical recovery. Discontinuation of drug therapy, however, was followed by relapse and further invasion by the same organism. A literature survey of Nocardia asteroides infections treated with trimethoprim/sulfamethoxazole disclosed that posttreatment follow-up is often too brief or unknown, making the ultimate success of therapy uncertain. (Arch Intern Med139:355-356, 1979)

Information-Theoretic Approach: Application to Molecular Collisions

Abstract: What we now know as information theory(1,2) was introduced by Shannon(3) and Wiener(4) in the late 1940s. Like thermodynamics, the need for the theory was motivated by very practical considerations. Just as the question “Are there natural limits to the conversion of heat into mechanical energy?” prompted Carnot’s formulation of the second law of thermodynamics, the question “Are there theoretical limitations to the number of messages that can be reliably transmitted via a communication channel?” led Shannon to the second theorem of information theory. It is not our purpose here to review the rest of the story but to present a utilitarian summary of the current practice of information theoretic methods in the study of molecular collisions. The area has been previously reviewed(5–9) and a “handbook” of results at a given total energy is available.(10) In this chapter we focus attention on the theory from the experimentalist’s point of view, although the “experimental” data to be treated may well include computational results, e.g., from classical trajectory calculations. We intend to describe the current usage and, where appropriate, to make specific recommendations. This chapter is thus a handbook and does not always provide detailed derivations, nor does it provide a literature survey (which can be found, e.g., in Reference 9). We apologize to those of our colleagues whose work is not explicity cited.

Literature survey: methods for the removal of iodine species from off-gases and liquid waste streams of nuclear power and nuclear fuel reprocessing plants, with emphasis on solid sorbents

Abstract: Emphasis was focused on the operating parameters that most strongly affected the optimization of the processes used to treat actual process or feed streams which simulated actual compositions occurring at nuclear facilities. These parameters included gas superficial velocity, temperature, types of organic and inorganic contaminants, relative humidity, iodine feed-gas concentration, iodine species, column design (for both acid-scrub and solid sorbent-based processes), sorbent particle size, run time, intense radiation (solid sorbents only), and scrub-acid concentration. The most promising acid-scrub process for removal of iodine species from off-gases appears to be Iodox. The most promising solid sorbent for removal of iodine species from off-gases is the West German Ag-KTB--AgNO/sub 3/-impregnated amorphous silicic acid. The tandem silver mordenite--lead mordenite sorbent system is also quite attractive. Only a limited number of processes have thus far been studied for removal of iodine species from low-level liquid waste streams. The most extensive successful operating experience has been obtained with anion exchange resins utilized at nuclear power reactors. Bench-scale engineering tests have indicated that the best process for removal of all types of iodine species from liquid waste streams may be treatment on a packed bed containing a mixture of sorbents with affinity for both elemental andmore » anionic species of iodine. 154 references, 7 figures, 21 tables.« less

Isolation of the catalytic subunits of cyclic AMP-dependent protein kinases from different mammalian tissues on the basis of charge differences of their subunits.

Abstract: Both, the experimental data and a literature survey presented reveal common charge differences in the subunit composition of cAMP-dependent protein kinases from a variety of mammalian tissues. In general, the holoenzymes (type I and II) focus at pH 4.5-5.5, the cAMP-binding regulatory subunit below pH 4, whereas catalytic subunits are found at pH 6.7-9.1. For the purification of the catalytic subunits, the anionic holoenzymes of a variety of rat and rabbit organs as well as mouse and human-derived tissue culture cells were adsorbed to DEAE-cellulose. The catalytic subunit from the particular isoenzyme were selectively eluted at an appropriate ionic strength depending on the isoenzyme elution pattern by small amounts of cAMP. Extraction of tissues with Triton X-100 increased enzyme yield. Improved elution of the enzyme was accomplished by 8-(4-aminobutyl)amino-cAMP instead of cyclic AMP. Carboxymethyl-cellulose chromatography leads to both, concentration and, if necessary, to further purification of the enzyme.

Longitudinal joint systems in slip-formed rigid pavements. volume ii. analysis of load transfer systems for concrete pavements

Abstract: This report covers the development of rigid pavement joint models, the theoretical evaluation of joint systems and the results and conclusions reached from these studies. This is Volume II of a three volume series on the design and construction of longitudinal joint systems in slip-formed concrete pavements. Volume I - Literature Survey and Field Inspection - dated January 1979, was issued earlier. Volume II - User's Manual is now being printed. This report emphasizes the theoretical evaluation of joint systems. Although the study was primarily for the analysis of longitudinal joint systems for use with slip-formed pavements, the data is applicable to the analysis/design of other types of joints in rigid pavements. The study has been divided into 4 phases. Part 1, Extensive Literature Review; Part 2, Development of Rational Structural Analysis Methods; Part 3, The Finite Element Computer Model is compared with other theoretical Methods; Part 4 Studies Were Made to Define the Interaction of Joint Components and How They Affect the Stresses and Deflections of the Pavements. Cost data are given for the various alternate systems considered. (Author)

Ride dynamics of articulated vehicles - a literature survey

Abstract: SUMMARY This paper presents a review of the available literature describing the methods of modelling the vibrational response of articulated vehicles to the road inputs at the tire contact points. It states and discusses the mathematical techniques that have been put forward for obtaining road input characteristics, for modelling the vehicles in a range of degrees of freedom, and for performing the analysis necessary to obtain the vibrational response. Finally the indices that have been proposed for ride comfort and ride safety are given and the manner in which various researchers relate these to the vibrational characteristics of the vehicles is described.

Literature Survey of Bacterial, Fungal, and Drosophila Assay Systems Used in the Evaluation of Selected Chemical Compounds for Mutagenic Activity

Abstract: Literature reports were surveyed, with results noted from experiments in seven nonmammalian assay systems used for the detection of mutagenicity or other related genetic effects. A comparison was made of the activities of 54 selected noncarcinogens, procarcinogens, and ultimate carcinogens as revealed by these test systems. Of the compounds tested, 49 (91%) were active in one or more of the assays, and 42 (78%) were positive in at least one system without having to be metabolically activated. In one or more test systems, 17/17 (100%) of the ultimate carcinogens, 27/28 (96%) of the procarcinogens, and 6/9 (67%) of the noncarcinogens were positive. The Ames Salmonella-microsome assay responded with increased mutation frequency to 37/44 (84%) of the carcinogenic compounds but to only 2/8 (25%) of the noncarcinogens tested. The Drosophila system responded to 19/21 (90%) of the carcinogens and to 3/6 (50%) of the noncarcinogens. Prophages were induced when lysogenic bacteria were exposed to 12/21 (57%) of the carcinogens, but not enough tests were done with the noncarcinogens (1/3, or 33%) for a comparison. The other systems reviewed, such as the killing of repair-deficient bacteria, mutations in Escherichia coli and Neurospora crassa, and the host-mediated assay, were not challenged by enough of the compounds for valid comparisons.

Tip vortex cavitation delay with application to marine lifting surfaces : a literature survey / by Gregory P. Platzer and William G. Souders.

Abstract: The generation of tip vortices from finite-span lifting surfaces degrades the overall effectiveness of these surfaces. An extensive literature survey pertaining to this viscous rollup phenomenon and the numerous concepts advanced for its alleviation has been made. Those concepts which appear applicable to delaying the formation of marine propeller tip vortex cavitation are highlighted, and further experimental investigations are recommended. (Author)

Zur Synthese phosphinkomplexierter d8-Metalltetrasulfide (Ni(II), Pd(II) und Pt(II)) mit Natriumpolysulfiden / On the Synthesis of Phosphine-Coordinated d8-Metal Tetrasulfides (Ni(II), Pd(II), and Pt(II)) with Sodium Polysulfides

Abstract: A short literature survey on phosphine-coordinated d⁸-metal tetrasulfides is given. Different results have been reported for the reactions of elemental sulfur with Pt(PPh₃)₄ (1). The reaction of sodium polysulfides, Na₂Sx, with the corresponding dihalides results in a clear-cut manner in the formation of the already known compounds tetrasulfidoethylenebis(diphenylphosphine)palladium(II) (6) and tetrasulfido-bis(triphenylphosphine)-platinum(II) (5), and the new compound tetrasulfido-ethylenebis(diphenylphosphine)-nickel(II) (13). Degradation reactions of [Pt(S₅)₃]²⁻(9) with triphenylphosphine, tri-p-tolylphosphine and ethylene-bis(diphenylphospbine) result in the formation of 5, and tetrasulfido-ethylenebis(diphenylphosphine)platinum(II) (4) and the new tetrasulfidobis(tri-p-tolylphosphine)platinum(II) (10). IR-spectra are reported.

A releationship between protein-degradation rates in vivo, isoelectric points, and molecular weights obtained by using density labelling.

Abstract: 1. Half-lives of five plant enzymes were estimated by rate-labeling with 2H2O on the assumption that loss of catalytic activity is equivalent to protein degradation. 2. This involved measuring band-broadening of activity profiles after isopycnic centrifugation. 3. Isoelectric points were determined by isoelectric focusing, and molecular weights were estimated by gel filtration. 4. The conclusion is drawn from the experimental evidence presented that a weak correlation exists between rates of degradation and isoelectric points (r = 0.699; P greater than 0.10; not significant). 5. A highly significant relationship exists between the logarithm of subunit size and half-life (r = -0.939; P greater than 0.02). 6. A literature survey confirmed the trends observed.

Accident and operational guidelines for continuous two-way left-turn median lanes (discussion and closure)

Abstract: An investigation was begun to provide highway designers and traffic engineers with more definitive information on the installation of left-turn median lanes. Primary emphasis was on documentation of experiences with continuous two-way left-turn median lanes; however, for purposes of comparison channelized one-way left-turn median lanes (raised and flush markings) were included. This paper presents a summary of the detailed investigation of the literature on left-turn lanes, the results of a survey of current practices and standards in Texas, results of field studies, and guidelines for use. A literature survey and analysis of questionnaires returned by representatives from Texas cities and the Texas State Department of Highways and Public Transportation suggested areas in which definitive guidelines were required. Based on the analysis of these two phases of the study, field studies were conducted that concentrated on operational characteristics, accident experience, and currently accepted practices. The analysis of the data collected on left-turn-lane sites revealed many characteristics, patterns, and relationships of accidents and operational experiences. A brief summary of the conclusions and findings is included, and recommendations are provided to improve current practices. In the operational characteristics phase of the study, emphasis was placed on the lateral placement of vehicles in the left-turn lane and the entering and maneuvering distances of vehicles within the lane. These suggest the characteristics of driver behaviour that can be used by traffic engineers and highway designers in determining the optimum design elements for two-way left-turn lanes. (Author)

Thermodynamic properties of the systems benzene-chloroethanes

Abstract: This paper presents the experimental data on vapor-liquid equilibrium and heats of mixing of mixtures of benzene with 1, e-dichloroethane, 1, l, 1 -trichloroethane, and lt1,2,2-tetrachloroethane.A literature survey revealed that the heats of mixing of benzene-l,2-dichloroethane have been studied and Table I shows the extent of study on this system.

The possible impact of vessel wakes on bank erosion

Abstract: A summary is given of the knowledge available on vessel-generated wake, and the possible impact of this vessel wake on bank erosion. A literature survey was conducted to identify the various causes of bank erosion along waterways. A summary of the various natural effects and possible vessel effects is provided. Recession of waterway banks involves a large number of effects. The physical and chemical nature of the channel's water, the materials forming the bank, and the groundwater may increase the soil's erodibility by formerly noneroding water currents, wind waves, or vessel wakes. No computational methods exist for linking a vessel with a chosen hull shape, traveling at a chosen speed in a channel of chosen depth and chosen cross-sectional area and shape with banks of chosen height and materials, to a predicted occurrence of erosion.

Photobiological Production of Hydrogen: A Solar Energy Conversion Option

Abstract: This literature survey of photobiological hydrogen production covers the period from its discovery in relatively pure cultures during the early 1930s to the present. The focus is hydrogen production by phototrophic organisms (and their components) which occurs at the expense of light energy and electron-donating substrates. The survey covers the major contributions in the area; however, in many cases, space has limited the degree of detail provided. Among the topics included is a brief historical overview of hydrogen metabolism in photosynthetic bacteria, eucaryotic algae, and cyanobacteria (blue--green algae). The primary enzyme systems, including hydrogenase and nitrogenase, are discussed along with the manner in which they are coupled to electron transport and the primary photochemistry of photosynthesis. A number of in vivo and in vitro photobiological hydrogen evolving schemes including photosynthetic bacterial, green algal, cyanobacterial, two-stage, and cell-free systems are examined in some detail. The remainder of the review discusses specific technical problem areas that currently limit the yield and duration of many of the systems and research that might lead to progress in these specific areas. The final section outlines, in broadest terms, future research directions necessary to develop practical photobiological hydrogen-producing systems. Both whole cell (near- to mid-term) andmore » cell-free (long-term) systems should be emphasized. Photosynthetic bacteria currently show the most promise for near-term applied systems.« less

The frequency of pericardial effusions in bacterial meningitis.

Abstract: Because of our experience with four cases of purulent pericarditis complicating bacterial meningitis during a 13-month period, we performed a prospective study to determine the frequency of this complication. Echocardiograms were done on 100 patients with bacterial meningitis. Small or moderate pericardial effusions were detected in 19 patients, but none had symptoms or signs related to the effusion. Pericardiocentesis was done in one infant; all the other effusions resolved spontaneously. Patients with effusion were significantly younger than those without this complication, but no other significant risk factors were identified. A literature survey indicated that symptomatic pericarditis occurs in fewer than 1% of patients with meningitis. Conversely, in series of cases of purulent pericarditis, associated meningitis was reported in 12% of patients. We concluded that pericardial infection is common in patients with meningitis but that it is usually of no clinical significance and resolves with antibiotic therapy.