Tissue Culture Test Research Articles

Tissue-Culture and Suckling Mouse Tests of Toxigenicity in Peat-Based Composts of Fish and Crab Wastes

ABSTRACT Unfinished composts prepared from peat, fish scrap, crab scrap and seaweeds were found by tissue-culture tests to contain some toxic components present or formed in starting materials. However, no toxins tested were present in the mature composts. The data thus revealed the usefulness of the tests, and high hygienic quality of the composts.

A solid phase fluorescent immunoassay for the rapid detection of virus antigen or antibodies in fetuses infected with porcine parvovirus.

A solid phase fluorescent immunoassay using polyacrylamide beads coated with rabbit anti-porcine parvovirus antibodies has been developed and utilized in the diagnosis of porcine parvovirus infection. The antibody-coated beads (immunobeads) were used both to detect virus in mummified fetal tissues and to demonstrate specific antibodies in serum and ovarian follicular fluid. The immunobeads assay (IBA) was as sensitive as ELISA but more sensitive than virus isolation using tissue culture and haemagglutination tests. Both mummified and normal fetuses were obtained after experimental infection of SPF pregnant gilts. Using immunobeads, porcine parvovirus antigen was found in all mummified fetuses, but was found in only 1 out of 17 normal fetuses.

Iodized Cancer Therapy

Iodized Cancer Therapy

Detection of Clostridium difficile toxin A by immunoblotting

A clinical isolate of Clostridium difficile has been tested for its toxin production. Both toxins, toxin A and toxin B, could be detected by tissue culture and in animal models as well. Antibodies against a crude toxin A preparation have been prepared. These antibodies are able to neutralize the toxin both in the mouse lethality test and tissue culture test systems. The specificity of this antiserum has been analysed by electroimmunoprecipitation methods. Using immunoblotting, it could be demonstrated that the antigenicity of toxin A after SDS polyacrylamide gel electrophoresis under denaturing and reducing conditions was still preserved. The molecular weight of toxin A has been estimated to be 250000. Immunoblotting offers a simple and reliable procedure for toxin A detection from culture supernatants of C. difficile.

The in vitro toxicity of cobalt-chrome-molybdenum alloy and its constituent metals

Cobalt-chrome-molybdenum alloys are widely used in orthopaedic implants. Although they are relatively well tolerated, complications (including loosening and tissue necrosis) still occur and sometimes appear to be due to incomplete biocompatibility of the alloy. To investigate the local effect of the alloy on cells derived from the musculo-skeletal system, primary lines of fibroblastic cells from newborn rats were exposed to powders of cobalt-chrome-molybdenum alloy and its main constituents cobalt, chromium nickel and molybdenum. The toxicity of the metals was determined by counts of total cell number and of abnormal cells at intervals from 2 to 12 d. The alloy was much less toxic than cobalt or nickel and the pattern of toxicity was different for each metal. The results emphasize the difficulty of devising a single tissue culture test of toxicity which will measure the toxicity of any potential implant material.

Use of in vitro method to predict response of human ovarian carcinoma cells to chemotherapeutic agents

In vitro tissue culture and sensitivity tests were carried out on 16 cases of ovarian cancer to select the right anticancer drug(s) on an individual basis. The predictive accuracy of the in vitro drug sensitivity tests were 81.8%. The drug(s) suggested by in vitro tests did not reveal any correlation to the type of ovarian cancer. The drug sensitivity of cells from primary growth was different from that of secondary growth. The in vitro screening test also provided the choice of the next best drug(s), once the tumor had become resistant to a particular drug(s). Thus, the overall prognosis of patients at an advanced stage of malignancy could be improved with the help of in vitro predictive tests.

Chemosensitivity tests by a miniclone technique.

A modified miniclone method has been adopted to tissue culture testing of sensitivity to cytostatic drugs. The technique permits detailed microscopic clonal analysis of multiplication of single cells under conditions of 100% plating efficiency of certain selected established tumor lines or normal cells. Three different response parameters were distinguished--cytolysis, cytostasis and replicative capacity of cell fraction capable of multiplication. Notable differences were found among the five drugs tested--adriamycin, alkeran, BCNU, platinol and streptozocin.

Enterotoxigenic and enteroinvasive Escherichia coli strains belonging to a new O group, O167.

A new Escherichia coli O group, O167, is described. Its O antigen is related to that of Shigella boydii 3. A total of 29 strains belonging to the new O group were examined. Three strains were determined to be invasive by the Sereny test and by tissue culture tests and were non-enterotoxigenic. All three were nonmotile and failed to decarboxylate lysine. A total of 26 strains were noninvasive. Of these, 25 were motile, 24 decarboxylated lysine, and 19 were enterotoxigenic, 17 producing heat-stable enterotoxin only and 2 producing heat-labile enterotoxin only. This is the first description of the occurrence of enterotoxigenic and enteroinvasive strains in the same E. coli O group.

Tissue culture technique for routine isolation of street strain rabies virus.

A tissue culture test for the primary isolation of street strain rabies virus from the brains of suspect animals was evaluated. It was found to be reliable and comparable in sensitivity to the standard mouse inoculation technique. The test, which yields final results in 48 h, was performed in BHK-21 cells on tissue culture chamber slides. The addition of diethylaminoethyl dextran to the cell suspension before seeding the slide promoted the subsequent viral invasiveness of positive test specimens. The method described may be considered as a substitute for the mouse inoculation test which is currently used as a backup to the fluorescent antibody test in the diagnosis of rabies.

Metabolism of Indole-3-acetic Acid

The biological activity of 20 l-alpha-amino acid conjugates of indole-3-acetic acid (IAA) to stimulate cell elongation of Avena sativa coleoptile sections and to stimulate growth of soybean cotyledon tissue cultures has been examined at concentrations of 10(-4) to 10(-7)m. In the Avena coleoptile test, most of the amino acid conjugates stimulated elongation. Several of the conjugates stimulated as much elongation as IAA but their half-maximum concentrations tended to be higher. Some of the more active conjugates were alanine, glycine, lysine, serine, aspartic acid, cystine, cysteine, methionine, and glutamic acid.In the soybean cotyledon tissue culture test, all of the l-alpha-amino acid conjugates of IAA stimulated growth except for the phenylalanine, histidine, and arginine conjugates. Most of the conjugates produced responses at least as great as that caused by IAA. Conjugates with half-maximum concentrations lower than IAA included cysteine, cystine, methionine, and alanine. These conjugates exceed the IAA-induced callus growth at all tested concentrations. Other conjugates significantly better than IAA at 10(-6)m were serine, glycine, leucine, proline, and threonine.

Studies on plant growth‐regulating substances

SUMMARYA report of an alkoxypurine showing cytokinin activity is presented. This compound, 6‐benzyloxypurine, has been tested in three tests and in two of these, a wheat leaf senescence and a young coleoptile test, the compound is as active as benzyladenine or kinetin. Although it is much less effective on molar basis than these compounds in a tobacco tissue culture test, it is as active at its optimum concentration. In addition to promoting cell division the presence of 6‐benzyloxypurine leads to morphological differentiation within the tobacco stem tissue, and whole plants have been grown without altering the nutrient medium.

In vitro lymphoblastoid transformation in the presence of tuberculin as a diagnostic aid in tuberculous meningoencephalitis.

Precise diagnosis of tuberculous meningoencephalitis is often not possible because of the poor rate of isolation of acid-fast bacilli from cerebrospinal fluid and the negative response to intradermal tuberculin in a large number of patients. A tissue culture test measuring blastoid transformation of peripheral blood lymphocytes in the presence of tuberculin purified protein derivative was eval­ uated as a diagnostic approach in 24 patients with meningoencephalitis. An in vitro response to purified protein derivative was obtained in 20. Demonstration of tuberculin sensitivity in these patients provided confirmatory evidence of infection with Mycobacterium tuberculosis. Only in 6 of these 20 patients could the diagnosis be made confidently from other data. It was concluded that the in vitT,) lymphoblastoid transformation in the presence of purified protein derivative may be a useful diagnostic aid in patients suspected of having tuberculous meningoencephalitis.

STUDIES ONSTACHYBOTRYS ALTERNANS

Low doses of stachybotrys toxin were administered per os to groups of mice in early pregnancy. The toxic material was given either in the form of infected grain, liquid growth medium or partly purified toxin preparation. The administration took place mostly either as a single dose on the 3rd or 5th day of pregnancy or during a five‐day period in the feed. The toxin amounts administered varied from 3 to 4000 tissue culture units (TCU), measured by the mouse fibroblast tissue culture test. The proportion of pregnant mice in all toxin treated groups was 70.7 per cent and that in the control group was 90.5 per cent. The difference is statistically significant. Statistically significant differences were also demonstrated in the frequency of dead, resorbed and stunted foetuses and in the average litter size of live normal foetuses between the control group and the groups administered 100–4000 TCU of the stachybotrys toxin. The results thus provide experimental evidence that stachybotrys toxin can affect detrimentally foetuses in doses low enough not to cause any definite clinical signs of illness in pregnant females. The histopathological study revealed uteroplacental haemorrhages in toxin treated animals. This finding may be indicative of the mechanism of action by toxin.

Identification of viruses involved in the 1971 outbreak of hemorrhagic disease in southeastern United States white-tailed deer.

Tissues and serum from white-tailed deer (Odocoileus virginianus) in the southeastern United States were taken during an outbreak of hemorrhagic disease. These were subjected to virus isolation attempts in tissue culture and several serological tests (plaque neutralization, complement fixation, agar gel precipitation). Both epizootic hemorrhagic disease of deer virus (EHDV) and bluetongue virus (BTV) were isolated and evidence of their presence demonstrated serologically. All of the evidence supported previous suggestions that these two agents are antigenically distinguishable.

Toxicity Profile of Chloroacetaldehyde

Chloroacetaldehyde, a probable metabolite of 2-chloroethanol (ethylene chlorohydrin), was studied in a number of in vivo animal systems, in in vitro hemolysis tests, and in tissue cultures to obtain a toxicity profile of the compound. Acute toxicity tests were conducted in mice, rats, guinea pigs, and rabbits by one or more routes of administration. Tissue culture tests utilized both the agar-overlay and protein assay methods. Irritant activity was evaluated by intramuscular implantation, intradermal injection, and dermal and ophthalmic applications in the rabbit. Acute cardiovascular effects in rabbits were also determined. Sleeping-time tests in mice were conducted to assess the effect of chloroacetaldehyde pretreatment (inhalation and intraperitoneal) upon drug-metabolizing enzymes. The compound was tested in guinea pigs for its sensitizing potential. Cumulative (30 daily injections) and subacute (three injections per week for 12 weeks) toxicity studies were conducted to evaluate subtle toxic effects (e.g., weight gain, hematology, and histopathology) as well as lethality. Chloroacetaldehyde is a very toxic and irritating compound in acute tests; in tests of longer duration, most of the parameters measured appeared to be normal in animals that survived its lethal activity. The acute toxic effects of chloroacetaldehyde are compared with those of 2-chloroethanol. The former is inherently more toxic and irritating, while the latter exhibits greater ease of quantitative penetration through the GI tract and the intact skin.

Serum hepatitis in Swedish track-finders.

DURING the last two decades increasing interest has been taken in the problems of hepatitis. Many attempts have been made to adapt hepatitis virus to different laboratory animals, but so far no suitable species has been found, nor have the efforts to devise methods for cultivation of hepatitis virus in tissue culture or immunologic tests been successful although interesting results have been reported.1 2 3 3a Therefore, much current knowledge is based on information obtained from studies on volunteers4 5 6 7 8 or in institutional outbreaks.9 10 11 Viral hepatitis is usually divided into infectious hepatitis caused by virus A and serum hepatitis caused by virus B. Although . . .

Development of a toxicity evaluation program for dental materials and products. I. Screening for irritant responses.

AbstractA broad dental toxicology screening program has been initiated to develop suitable testing methods for new dental materials or products which presently are not considered as drugs. In the report presented here, 42 materials or products have been included in an acute toxicity screening program for the evaluation of irritancy properties. Depending upon the state of the material or product, one or more testing procedures were employed. These included: (1) implantation in rabbit muscle, (2) a tissue culture test, (3) an intradermal test in rabbits, (4) an eye test in rabbits, and (5) a dermal test in rabbits. With the limited number of materials or products, the most suitable method of testing solids was the implantation method and tissue culture. Tissue culture appeared to be the only useful method for powders while tissue culture and an intradermal test the most suitable method for liquids. Other materials and products will be included using these test procedures to note if one or two might eventually be selected as a preferred method of “irritancy” testing when a large number of materials or products are to be screened for a dental or medical application. The final evaluation of safety for a dental material or product must of course be based upon its intended use.

Reevaluation of plastic tubings currently used in medical and paramedical applications.

AbstractA tissue culture test and a 7 day implantation method in rabbits were used to screen the toxic potential of 50 tubings used in one or more medical or paramedical applications. Results of the tests revealed that approximately 32% of the tubings contained one or more ingredients which, when released to cells or tissue, caused a toxic response. A similar study six years previously showed that 52% of the tubings tested had toxic potential. It is apparent that improvements have been made in the medical tubings (from point of view of safety), but steps must still be taken to reduce the potential risk to levels approaching zero.

Minicultures of Mammalian Cells in a New Plastic Plate

A new disposable micro tissue culture plate was developed and tested for use in virological procedures. Miniature mammalian cell cultures (minicultures) were grown in these plates. Each plate contained 96 circular cultures in flat wells (7 mm in diameter). Replicate titrations of a number of viruses were performed in various tissues. Excellent reproducibility was demonstrated. Mean infectivity titers determined by miniculture methods were generally within 0.6 log 10 /ml of macro tube titrations. Standard tissue culture assay techniques such as hemadsorption, interference titration, and microneutralization were easily carried out with this method and were very reproducible. Development of this noncytotoxic disposable micro tissue culture plate now permits the routine performance of rapid, reliable, and reproducible tissue culture tests at a very significant reduction in cost and labor.

Minicultures of Mammalian Cells in a New Plastic Plate

A new disposable micro tissue culture plate was developed and tested for use in virological procedures. Miniature mammalian cell cultures (minicultures) were grown in these plates. Each plate contained 96 circular cultures in flat wells (7 mm in diameter). Replicate titrations of a number of viruses were performed in various tissues. Excellent reproducibility was demonstrated. Mean infectivity titers determined by miniculture methods were generally within 0.6 log(10)/ml of macro tube titrations. Standard tissue culture assay techniques such as hemadsorption, interference titration, and microneutralization were easily carried out with this method and were very reproducible. Development of this noncytotoxic disposable micro tissue culture plate now permits the routine performance of rapid, reliable, and reproducible tissue culture tests at a very significant reduction in cost and labor.