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Cells transformed by Friend virus in liquid suspension culture respond to low concentrations of dimethylsulfoxide by initiating hemoglobin synthesis. The kinetics of appearance of such differentiated erythroid cells is consistent with either the induction of differentiation in a uniformly susceptible population of transformed cells or selection for the growth of a distinct erythropoietic subpopulation. The dimethylsulfoxide response of individual colonies of cells transformed by Friend virus grown in semisolid medium was studied in order to distinguish between these alternatives. The data do not support a selective effect of dimethylsulfoxide on the growth of a unique erythropoietic subpopulation; they indicate, rather, that the 745A strain of cells transformed by Friend virus consists of a relatively uniform population of dimethylsulfoxide-sensitive erythropoietic cells.

A sheared liquid suspension whose flow is reversed remembers with various degrees of perfection all earlier configurations of the particles. The memory effects, studied primarily because of their importance in suspension rheology, may be of wider significance.

The extraction procedure for the official first action infrared analysis for carbaryl in formulations, 6.206–6.208, has been modified by the addition of anhydrous granular sodium sulfate to make the method applicable to liquid suspension formulations of carbaryl. A limited collaborative study of the modified method yielded a standard deviation of ±1% at the 40% level and a coefficient of variation of ±2%. The modification has been adopted as official first action.

Millimeter wave phase shifters based on microwave-induced birefringence in artificial Kerr media have been demonstrated. Full-wave phase shifts produced by alignment of rod-shaped particles in a liquid suspension make possible the development of millimeter wave analogs of nonlinear optical devices.

SummaryAn open study was carried out in 40 elderly patients suffering from osteoarthrosis of the hip to assess the effectiveness of 200 mg flurbiprofen daily, given either in tablet or liquid suspension form, over a period of 4 weeks. Statistical evaluation of the results in the 19 patients admitted to analysis showed that flurbiprofen produced significant improvement in daytime and overnight pain, and did not impair their mental status, as assessed on a modified Goldfarb scale. No significant differences were found between the response of the two groups, except for severity of night pain. Fourteen of the 19 patients included in the analysis reported side-effects, as did 18 of the 21 patients who were excluded. Only 7 patients (4 on tablets, 3 on liquid), however, were withdrawn from the trial for this reason.

Summary. The capacity of cells grown in colonies derived from human haematopoietic cells to phagocytize bacteria and to reduce nitroblue tetrazolium (NBT) was studied as a measurement of functional maturation. Marrow cells from 12 non-leukaemic patients, fivc patients with acute non-lymphocytic leukacmia, and cells taken from a myeloblastic cell line established from a patient with acute myelo-genous leukaemia (AML) were studied. Cells were cultured in soft agar with normal human leucocyte feeder layers as the source of stimulating factor. While the leukaemic marrows gave rise to fewer colonies than the non-leukaemic marrows, colony formation by the AML cell line was extensive. In all instances colony formation was completely dependent upon the presence of the leucocyte feeder layers. Suspensions of pooled colonies contained 42% mature granulocytes in non-leukaemic cultures and 41% in the leukaemic cultures. Granulocytes from these cultures showed active phagocytosis of Staphylococcus aureus and reduction of NBT. In cells taken directly from the liquid suspension culture of the AML cell line, no mature granulocytes nor phagocytosis were noted, whereas 35% and 26% of the cells removed from the colonies formed by these cells were classified as mature granulocytes, or demonstrated phagocytosis and NBT reduction respectively. These observations indicate that granulocytes in soft agar colonies derived from human haematopoietic cells are functionally mature, and that cells derivcd from a human AML cell line have the capacity to form colonies with normal maturation, if they are provided with an appropriate stimulating factor.

Mutagenicity test systems using Escherichia coli are characterized by the great diversity of tester strains and substrains (e.g., several different repair-proficient and repair-deficient strains), of genetic endpoints (several different forward- and back-mutation types, lysogenic induction), and of testing methods (spot test, liquid suspension test, fluctuation test). There is no single set of experimental conditions where all the substances of this study would have been assayed. It is, therefore, difficult quantitatively to compare the results that have been gained under the influence of different experimental factors. As an example, the lowest detectable mutagenic activity of MMS is about 1 × 10−3 mole/1, in usual liquid suspension tests, whereas newly developed fluctuation tests (1) allow the detection of MMS concentrations as low as 45 × 10−6 mole/1. Nevertheless, attempts have been made to estimate roughly the relative mutagenic potencies of the test substances as indicated further in the text. Induction of vegetative growth of prophage in lysogenic cells has been added as a further genetic endpoint, since it was repeatedly demonstrated to be correlated to mutagenic activity.

The purpose of this experiment is to measure, by a sensitive manometric method, the rate of photosynthesis in a unicellular green alga as a function of light intensity at two temperatures under conditions where carbon dioxide is in abundant supply. A very large part of the research on photosynthesis has been done with cultures of unicellular green algae, which afford several conveniences compared to terrestrial seed plants. The unicellular algae can be grown in defined inorganic culture media under standard and reproducible conditions; uniform, dense, very active samples can be prepared and pipetted as a liquid suspension; and rate of photosynthesis can be accurately measured as rate of oxygen production by sensitive manometric methods.

The medical management of severe reflux esophagitis (symptoms of heartburn and dysphagia plus objective endoscopic signs) can sometimes offer relief of symptoms, but is often less successful in healing endoscopic abnormalities (Wes-dorp 1984).

To examine the relationship between viability of acute myelogenous leukemia (AML) blasts in liquid suspension culture and the occurrence of myeloid maturation in culture, total and differential cell counts and viability as determined by trypan blue dye exclusion were followed over 21 days of culture. A significant positive correlation was found between viability of cells on day 21 of culture and percentage of mature cells present. These data suggest that myeloid maturation may be a mechanism by which AML cells maintain viability in an adverse environment.

To study the ability of acute myelogenous leukaemia blasts to spontaneously differentiate in vitro, bone marrow and/or blood mononuclear cells from 63 patients with acute myelogenous leukaemia were incubated in liquid suspension cultures containing human serum, without addition of chemical inducers of differentiation. Cultures were examined weekly for disappearance or persistence of blasts, and for appearance of morphologically recognizable granulocytes and macrophages. Culture outcomes were extremely variable, ranging from lack of appearance of differentiated cells to complete disappearance of blasts with replacement by mature cells. In 50 cases an increase (25-185%) in the absolute number of differentiated cells in culture was noted during the culture period. Full differentiation was seen exclusively in cultures from 13/48 (27.1%) patients studied at diagnosis, as compared to 0/20 patients studied at relapse (P less than 0.01). The ability to fully or partially differentiate in culture was lost to a significant degree at relapse (13/20 patients) as compared to diagnosis (48/48 patients, P = 0.0001). At diagnosis full differentiation in culture was associated with a significantly higher remission rate than partial differentiation (89% versus 40%, P less than 0.02). Origination of mature cells from leukaemic rather than normal precursors was suggested by the appearance of Auer rods in mature cells in seven cases, by the correlation of types of differentiated cells seen in culture with the FAB class of leukaemia and by cytogenetic data in one case.

A simple and less expensive method for the preparation of spherical matrixes of prolonged-release drugs was developed from liquid suspension. The drugs dispersed in distilled water were agglomerated with a small amount of organic solution or melt of matrix material. The process, called a “solution” or “melting” method, depended on the state of matrix material. In the present study, sulfamethoxazole and sulfanilamide were agglomerated with white beeswax and ethylcellulose. Furthermore, the parameters affecting the average size and release behavior of the resultant matrixes were investigated. Increasing the amount of matrix material used yielded large matrixes and prolonged-release action. The drugs rendered hydrophobic by surface treatment produced larger matrixes that released drug more slowly than untreated drugs. The sizes of the matrixes decreased and became uniform with increasing agitation speed. The sulfamethoxazole matrixes with wax proved to be enteric coated since the release rate was fast in the alkaline test solution (pH 7.5) but slow in the acidic one (pH 1.2).

The mutagenicity of 99 chemicals was determined in a standard Salmonella typhimurium assay with the use of strains TA1535 and TA1538; the DNA-modifying capacity was determined with normal and DNA polymerase-deficient Escherichia coli strains. The following categories of chemicals were studied: alkylating agents (15); nitrosamines, hydrazines, and related substances (8); heterocyclics (10); aromatic amines (36); polycyclic aromatic hydrocarbons (11); amides, ureas, and acylating agents (7); antimetabolites (5); inorganics (4); and promoters (3). Of the substances studied, 21 were known noncarcinogens, 21 were ultimate carcinogens, and 45 were procarcinogens. Of the noncarcinogens, 35, 30, and 25% were positive in the Salmonella, E. coli, and both systems, respectively. All of the ultimate carcinogens were detectable as mutagens of DNA-modifying agents; 79, 100, and 79% gave positive tests in the Salmonella, E. coli, and both systems, respectively. Of the procarcinogens 72% were identifiable by these procedures: 52, 67, and 48% in the Salmonella, E. coli, and both assays, respectively. A tabulation of the combined data for ultimate carcinogens and procarcinogens indicates that 77% of the carcinogens gave positive results: 61, 74, and 59% in the Salmonella, E. coli, and both assays, respectively. We suggest that, for prescreening procedures with microbial assays, S. typhimurium strains TA98 and TA100 be included and the standard E. coli DNA polymerase-deficient assay be run in tandem with the Salmonella mutagenicity assay. When the standard E. coli DNA polymerase-deficient assay does not give interpretable results because of the lack of zones of growth inhibition, a modified assay with the use of liquid suspension should be performed.

This paper discusses the need for accurate calibration artifacts in the optical particle sizing community, and details work at the U.S. National Bureau of Standards toward the development of such materials using optical techniques for certification.

1. In an experiment in which a high-fat supplement was given in the dry form to lambs offered dried grassad lib., both the voluntary intake and digestibility of the dried grass were reduced. When the high-fat supplement was given in a liquid suspension so that the rumen was by-passed, the voluntary intake and digestibility of the dried grass were not significantly altered.2. The effect of injecting an emulsion of tallow into the rumen of sheep on rumen metabolism was studied in another experiment. Increasing the fat supplementation lowered the rate of digestion of both dried grass and cotton thread, lowered markedly the concentration of rumen ammonia, and raised the proportion of propionic acid in the rumen.

The effects of mouse L-cell interferon (IFN) on growth of mouse bone marrow cells and their differentiation into macrophages and granulocytes were investigated in a liquid suspension culture system with two different types of colony-stimulating factor (CSF). Within 7 days, most bone marrow cells differentiated into macrophages in the presence of macrophage colony-stimulating factor (M-CSF) derived from mouse fibroblast L929 cells, but into both granulocytes (40%) and macrophages (23%) in the presence of a granulocyte-macrophage colony- stimulating factor (GM-CSF) from mouse lung tissue. IFN inhibited growth of bone marrow cells with both M-CSF and GM-CSF, but had 20 times more effect on bone marrow cells stimulated with M-CSF than on those stimulated with GM-CSF. A low concentration of IFN (50 IU/ml) stimulated production of macrophages by GM-CSF in liquid culture medium, whereas it selectively inhibited colony formation of macrophages in semisolid agar culture. IFN caused no detectable block of late stages of differentiation; mature macrophages and granulocytes were produced even when cell proliferation was inhibited by IFN. These results indicate that IFN preferentially affects growth and differentiation of the cell lineage of macrophages among mouse bone marrow cells.

WHEN they reach the stationary phase, the vegetative cells of Dictyostelium discoideum become adhesive and form multicellular aggregates before forming fruiting bodies. In shaken liquid suspension they form aggregates in two stages1. First, they produce loose amorphous clusters which, if deposited on a solid substratum, immediately disperse. In the second stage (6–7 h) the clusters have become tight, round or ovoid aggregates eventually covered with a thin cortical sheath. If deposited on solid substratum, they remain intact and immediately proceed to the next stage of fruiting body construction. The loose clusters are EDTA-sensitive, the tight aggregates are not2.

Methyl- (MNUA), ethyl- (ENUA), propyl- (PNUA) and butylnitrosourea (BNUA) have been tested for toxicity and mutation in a liquid suspension assay towards Escherichia coli WP2 and some of its repair deficient derivatives. A comparison of survival rates after nitrosourea exposure between WP2 and WP2 uvrA showed no difference between the two strains but a consistent difference in potency between the various nitrosoureas studied. Toxicity increased in the order MNUA less than PNUA less than ENUA less than BNUA. ENUA and PNUA induced a greater number of trp+ revertants in both strains than did MNUA and BNUA, particularly at low survival rates. None of these differences in biological potency could be accounted for by differences in rates of hydrolysis. ENUA, PNUA and BNUA were non-mutagenic towards WP2 lexA, WP2 recA and WP2 uvrA lexA, whereas MNUA did induce mutations. Ethyl methanesulphonate (EMS) was able to mutate WP2 lexA. These results are discussed in the light of current theories regarding the mechanism of action of these compounds.

The development of high-speed flow-systems, cell separation methods for automated analysis and sorting of single cells has provided a new dimension to biological investigations by making possible the isolation of cells with particular physical and biochemical properties from heterogeneous mixtures. Rapid advances in this technology, coupled with new preparation and staining techniques, now provide unique quantitative methods for analyzing specific cellular properties, thus contributing to new insights into cellular mechanisms. Individual cells in liquid suspension are typically analyzed at rates of up to 105/min by electrical and optical sensors that measure various cellular properties. Sensor signals are processed several ways, and the resulting data are displayed as frequency distribution histograms. The uniqueness of the method lies in the fact that measurements are made on each cell in the population at high speed. Since many cells are examined, statistical precision is high and small subpopulations can be detected with confidence. New cell staining techniques have provided high- resolution measurements of such modalities as DNA content. Also, other measurements not previously possible within a cell population now can be performed routinely. Improved instrumentation has been developed recently that incorporates several analytical techniques, permitting multiple measurements to be performed on the same cell.

In this paper we describe an experimental study of self-focusing bistable devices using a liquid suspension of dielectric particles as the nonlinear medium. We observe regions of multiple optical hysteresis in good agreement with theoretical predictions.

1. Fluids were given by mouth in various ways to young sheep. The extent to which closure of the oesophageal groove operated to direct the fluid to the abomasum was assessed by radiography.2. Salt solutions and milk given as a drench did not produce complete closure of the groove. However, when the animals were accustomed to sucking from a teat before weaning, any liquid suspension and also water, sucked from a bottle, passed entirely to the abomasum even in 12-month-old sheep.3. This technique may be useful when it is desirable to cause protein or other nutrients to by-pass fermentation in the rumen.

Procedures are described for obtaining efficient mating (zygote formation) in the heterothallic yeast Saccharomyces cerevisiae . The methods separate operationally the initial, mating-specific aggregation from subsequent steps in conjugation. This cell-cell interaction has been characterized. The data support the conclusions that (i) aggregation in liquid suspension is a random collision process, and (ii) only non-budded cells participate in aggregation. A mathematical model for the kinetics of aggregation in liquid suspension has been developed which is in good agreement with the experimental data.

Since the recent introduction of liquid suspension preparations of salicylamide, there has been some controversy about their efficacy as antipyretics. Although acetylsalicylic acid (aspirin) is available in palatable forms, it is difficult to prepare it in a liquid state, or to maintain the stability in solution. The correction of the febrile state of the patient and patient comfort are paramount responsibilities of a physician. Consequently, the question of whether salicylamide may replace acetylsalicylic acid as an antipyretic is very important, particularly in pediatrics. The further claims made as to the relative safety of the different preparations involved also require further elucidation. Background Over the years acetylsalicylic acid has proved to be one of the most reliable weapons in the physicians' armamentarium. It has been among the most valuable and frequently used pharmacotherapeutic agents throughout the range of medicine. Among other things, it is the basic analgesic against aches and pains

NYROP1, and Brown, Hoyler and Bierwith2, have claimed that it is possible to destroy a large proportion of the bacteria in a liquid suspension at sublethal temperatures by the application of high radio-frequency voltage gradients. Attempts have been made to confirm these results in order to determine the factors involved.

Publisher Summary Phosphor screens approximately 1 ½ -4 monolayers thick showed poor adhesion and this had to be enhanced in the various ways. The coated face is held, phosphor downwards, over a dish of water at 45°C for 1 min and is then kept for 20 min in an enclosed box containing a source of water vapor. This technique improves the adhesion to a considerable extent and the metal conducting film can be completely removed using HCI vapor or ammonium persulphate solution. The usual technique for producing phosphor screens is by settling the phosphor particles under gravity from a liquid suspension. Since this process becomes increasingly more lengthy and unreliable when particles of a size below 3-5 μm are used, alternative techniques have been investigated, namely, the Langmuir trough monolayer flotation method the electrostatic precipitation technique and an evaporation technique. Screens prepared by the various techniques were all incorporated into cathode-ray tubes for investigation. In order to prepare efficient thin-film phosphors, it is necessary at some stage to fire them at a temperature similar to that used in the preparation of the equivalent powder phosphor.

Callus from hypocotyls of white spruce (Picea glauca [Moench] Voss) was grown on agar under defined conditions with high levels of calcium nitrate. Transfer of callus to liquid suspension cultures and maintenance of suspensions either under a regime of constant temperature and light or under alternating conditions similar to those of a late spring day, affected the content of free sugars, tannins, and aldehydes. Under the alternating conditions the levels of these substances increased greatly compared to those under the constant environment. By contrast, vascularization of cell clumps, which was comparable to the differentiation of hypocotyls in seedlings, was obtained only under constant conditions. Cells at the centre of the clumps developed secondary wall thickenings and bordered pits, and were surrounded by cambial-like initials.

Research into methods of counting viable bacteria in the presence of many dead ones to yield a rapid microbiological assay did not reach that final objective, but advanced to several important milestones: (1) Methods and apparatus were reduced to practice wherein the light scattered from individual bacteria or clusters in liquid suspension was used for detection and size measurement. (2) The inhibition of mitosis of organisms in a sample, as a method of culturing the microbial giant form to test viability, proved difficult because of the variability of response among individuals in the population to the inhibiting agents and nutrients tested. However, the exploratory experiments produced samples useful for instrument testing. (3) Exploratory research indicated that changes in the dielectric constant of a minute sensing zone could be used to detect the presence of particles in a fluid passing through the zone, and that this method might also show the organization, composition, or uniformity of the particles. (4) We also concluded that the light-scattering apparatus could be used, with minor optical modification, to count fluorescent particles in a liquid.

Two dosages of a liquid suspension formulation of amoxicillin and potassium clavulanate were tested in 34 infants and children. The smaller dosage resulted in suboptimal plasma concentrations. With a greater dosage (3.3 mg of clavulanate per kg and 13.3 mg of amoxicillin per kg), the mean peak plasma concentrations were 1.6 micrograms clavulanic acid per ml and 4.9 micrograms amoxicillin per ml.

A means of observing high‐frequency vibrational modes on barium titanate ceramic disks has been developed, utilizing Bernoulli attraction forces in a liquid suspension of fine particles, patterns for vibrational modes covering the frequency band of 80 kcps to one megacycle and higher have been obtained.

High‐modulus carbon fibers in liquid suspension are aligned precisely by magnetic fields. Other man‐made fibers can also be aligned after coating with iron. This response has many applications in light‐scattering experiments and in the preparation of composites. Thin films of aligned fibers offer advantages in determinations of diameter and length distributions and in other types of examination.

Houseflies (Musca domestica) were infected with Campylobacter jejuni after being confined for 5 days in a Horsfall isolator containing 25-day-old chickens known to be fecal excretors of the organism. Contaminated flies, when subsequently transferred to a second unit, transmitted C. jejuni to specific-pathogen-free chickens. Allowing a sample of 32 houseflies to ingest C. jejuni in a liquid suspension resulted in recovery rates of 20% from the feet and ventral surface of the body and 70% from the viscera. These experiments demonstrated the potential role of flies in the dissemination of avian campylobacteriosis.

It seems that the value of gargles remains an undecided matter in the minds of physicians who have given the subject their attention. For this reason and because of extensive exploitation of gargles by advertisers to the lay public, we undertook objective studies of the comparative value of gargles and throat irrigations. For these observations, subjects used a thin liquid suspension of barium sulphate while lateral x-ray views of the head and neck were made. The first methods included (1) violent gargling, (2) gentle gargling and (3) tilting the head backward and allowing the suspension to run as far backward as possible without gargling. A study of the films showed that with all these methods the tongue is firmly pressed against the soft palate in such a position that the liquid cannot reach the anterior faucial pillars. Occasionally if the subject interrupted the procedure to take a breath of air

Stocks of L. multiflorum endosperm callus have been maintained in liquid suspension culture on a modified White's medium for 5 years. The mean doubling time under the conditions used is 3� 2 days. Best growth is obtained on sucrose; fructose and glucose are good carbon sources, whereas growth is only moderate on an equimolar mixture of both.