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Biomedical subjects

T Gold

Publications and source records attributed to T Gold.

6 recordsLinked to original sources
PubMed2005

Mediation of the in vitro cytotoxicity of green and black tea polyphenols by cobalt chloride.

The effects of Co2+ (as CoCl2) on the cytotoxicity of green tea polyphenol (GTP) and black tea polyphenol (BTP) extracts towards proliferation of immortalized human gingival epithelial-like S-G cells were studied. The 24 h potencies of GTP and BTP extracts, as determined with the neutral red (NR) cell viability assay, were greatly reduced in the presence of 250, but not of 50, microM Co2+. The cytotoxicities of the GTP and BTP extracts were due, in part, to their generation of hydrogen peroxide (H2O2) in the cell culture medium (DMEM). Progressively increasing the concentration of Co2+ in the tea polyphenol-amended cell culture medium resulted in a lowering of the level of H2O2. The cytotoxicity of freshly added H2O2 to S-G cells was abolished in the presence of 250 microM Co2+ and the level of freshly added H2O2 to cell culture medium was progressively lowered as the concentration of Co2+ was increased. Apparently, under the conditions of these studies, the decreases in the cytotoxicity of GTP and BTP extracts in the presence of CoCl2 were due to the rapid catalytic decomposition by Co2+ of the H2O2 generated in the tea polyphenol-amended cell culture medium.

Cell Line↗
PubMed1992

The deep, hot biosphere.

There are strong indications that microbial life is widespread at depth in the crust of the Earth, just as such life has been identified in numerous ocean vents. This life is not dependent on solar energy and photosynthesis for its primary energy supply, and it is essentially independent of the surface circumstances. Its energy supply comes from chemical sources, due to fluids that migrate upward from deeper levels in the Earth. In mass and volume it may be comparable with all surface life. Such microbial life may account for the presence of biological molecules in all carbonaceous materials in the outer crust, and the inference that these materials must have derived from biological deposits accumulated at the surface is therefore not necessarily valid. Subsurface life may be widespread among the planetary bodies of our solar system, since many of them have equally suitable conditions below, while having totally inhospitable surfaces. One may even speculate that such life may be widely disseminated in the universe, since planetary type bodies with similar subsurface conditions may be common as solitary objects in space, as well as in other solar-type systems.

Bacterial Physiological Phenomena↗
PubMed1980

Speech production in hearing-impaired children.

Investigations in recent years have indicated that only about 20% of the speech output of the deaf is understood by the "person-on-the-street." This lack of intelligibility has been associated with some frequently occurring segmental and suprasegmental errors. Errors of voicing and omission of consonants as well as vowel substitutions are common articulatory problems. Suprasegmental errors are associated with problems of timing, intonation, and voice quality. Yet, in spite of the relatively consistent findings regarding these frequently occurring errors, the correlation between the errors and overall speech intelligibility is less clear. The interrelationship between error types and the frequency of occurrence of a particular error type must be taken into consideration when interpreting the true effect of the error type on speech intelligibility. It is only when this is determined that one can begin to predict how much improvement to expect from correction of specific errors.

Adolescent↗
PubMed1980

The structure of segmental errors in the speech of deaf children.

A quantitative description of the segmental errors occurring in the speech of deaf children is developed. The method of description separates out those errors or characteristics that are common to all deaf speakers from those that are common to different subpopulations of the deaf (e.g., severely versus profoundly hearing impaired) from those errors or characteristics that are unique to individual speakers. Using this technique, the pattern of segmental errors is specified for several groups of children including deaf children at a school for the deaf as well as hearing-impaired children who have been mainstreamed into the regular school system.

Adolescent↗
PubMed1977

Time-dependent disruptive effects of apomorphine and alpha-methyl-p-tyrosine on development of morphine tolerance.

In rats the development of one-trial tolerance to the analgesic action of i.p. administered morphine is disrupted by the postadministration of apomorphine (30 mg/kg at 5 min but not at 3 h) or alpha-methyl-p-tyrosine (200 mg/kg at 5 min and 3 h but not at 12 h). Diethyldithiocarbamate or propranol has no disruptive effect. It is suggested that development of tolerance to the analgesic effects of morphine is mediated by sequential time-dependent biochemical processes.

Animals↗