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Biomedical subjects

C Martindale

Publications and source records attributed to C Martindale.

At least 19 recordsLinked to original sources
PubMed2005

DNA damage responses at low radiation doses.

Increased cell killing after exposure to low acute doses of X rays (0-0.5 Gy) has been demonstrated in cells of a number of human tumor cell lines. The mechanisms underlying this effect have been assumed to be related to a threshold dose above which DNA repair efficiency or fidelity increases. We have used cells of two radioresistant human tumor cell lines, one that shows increased sensitivity to low radiation doses (T98G) and one that does not (U373), to investigate the DNA damage response at low doses in detail and to establish whether there is a discontinuous dose response or threshold in activation of any important mediators of this response. In the two cell lines studied, we found a sensitive, linear dose response in early signaling and transduction pathways between doses of 0.1 and 2 Gy with no evidence of a threshold dose. We demonstrate that ATM-dependent signaling events to downstream targets including TP53, CHK1 and CHK2 occur after doses as low as 0.2 Gy and that these events promote an effective damage response. Using chemical inhibition of specific DNA repair enzymes, we show that inhibition of DNA-PK-dependent end joining has relatively little effect at low (<1 Gy) doses in hyper-radiosensitive cells and that at these doses the influence of RAD51-mediated repair events may increase, based on high levels of RAD51/BRCA2 repair foci. These data do not support a threshold model for activation of DNA repair in hyper-radiosensitive cells but do suggest that the balance of repair enzyme activity may change at low doses.

Ataxia Telangiectasia Mutated Proteins↗
PubMed2001

The impact of the Balanced Budget Act of 1997 on the physical therapy profession.

The Balanced Budget Act (BBA) of 1997 was one of the most significant acts of legislation ever to affect the physical therapy profession. Three months after the BBA was implemented, a survey of over 600 physical therapists in the state of Florida was conducted. This article examines the immediate impact of the BBA on physical therapists and their ability--or their perception of their ability--to maintain or successfully seek full-time employment in the profession.

Adult↗
PubMed2001

Oscillations and analogies. Thomas Young, MD, FRS, genius.

Thomas Young is arguably one of the greatest geniuses who ever lived, but most people have never heard of him, though he was renowned in his own era. He did important work in a large variety of scientific disciplines, but that was his downfall. Given the specialization of the present era, physicists do not appreciate how important his work in linguistics was, linguists do not appreciate the importance of his work in psychology, and so on. Despite his obscurity today, Young nicely exemplifies the traits that one finds in a genius of the first order: tendency toward analogical thinking, high intelligence, an amazing capacity for hard work, extremely wide interests, distaste for traditional dogmas, and very high self-esteem.

Creativity↗
PubMed1996

Oligonucleotide frequencies in DNA follow a Yule distribution.

We show that ranked oligonucleotide frequencies in both protein-coding and non-coding regions from several genomes fit poorly to the Zipf distribution, but that the same frequency data give excellent fit to the Yule distribution. The parameters of the Yule distribution for oligonucleotide frequencies in exons are the same (within error limits) as the parameters for introns. This precludes application of Yule or Zipf distribution of ranked oligonucleotide frequencies to annotating new genomic sequences.

DNA↗
PubMed1996

Radiosensitisation in normal tissues with oxygen, carbogen or nicotinamide: therapeutic gain comparisons for fractionated x-ray schedules.

METHODS: Radiosensitisation with oxygen, carbogen or nicotinamide alone and oxygen or carbogen combined with nicotinamide was compared in early and late responding normal tissues in rodents. X-ray treatments were delivered as single doses or fractionated schedules of 2 fractions in 1 day, 2, 12 and 36 fractions in an overall time of 12 days and 10 fractions in 5 or 12 days. Acute skin reactions, survival of intestinal crypts, breathing rate, reduction in the packed red-cell volume and clearance of 51Cr-EDTA were used as assays of epidermal, gut, lung and renal damage. RESULTS: Relative to air-breathing mice, carbogen or oxygen produced a small, and not always significant, increase in sensitivity (enhancement ratios < or = 1.15) in gut, lung and kidneys; however, in skin a dose enhancement of 1.2-1.3 was observed. The effect of nicotinamide in air, carbogen or oxygen was studied only in lung and gut. The drug produced variable but generally significant increases in radiosensitisation ( < or = 1.26) in all three gases. Relative to treatments in air, enhancement ratios for nicotinamide alone were usually slightly higher than those observed when either carbogen or oxygen were administered without the drug. With all three modifiers (i.e. oxygen, carbogen, nicotinamide alone or for the drug-gas combinations) there was no significant change in the enhancement ratios observed as the number of radiation dose fractions was varied. CONCLUSIONS: Comparisons with fractionated X-ray studies done previously in rodent tumours indicate that a therapeutic benefit, relative to lung, gut and renal damage, would be observed with oxygen or carbogen alone but not with nicotinamide alone. The greatest gain would be achieved with the combination of carbogen and nicotinamide, with which a benefit was observed even relative to epidermal damage. These results indicate that some decrease in normal tissue tolerance could be observed when using these modifiers in clinical radiotherapy and, although small, the appropriate dose reductions should be considered; caution should be exercised especially when carbogen and nicotinamide are used in conjunction with the more radical accelerated schedules.

Animals↗
PubMed1995

Noncoding DNA, Zipf's law, and language.

In the report "Continent-ocean chemical heterogeneity in the mantle based on seismic tomography" by Alessandro M. Forte et al. (21 Apr., p. 386), note 14 (p. 388) should have included the following sentence at the end. "We note, however, that this classical measure of significance does not take into account the red spectrum of the observed nonhydrostatic geoid, whose harmonic coefficients cannot be properly regarded as a random distribution; therefore, the statistical significance of the measured correlation coefficient is possibly less than 99%.

Base Sequence↗
PubMed1988

Primary process content in paranoid schizophrenic speech.

Free speech samples given by paranoid schizophrenics, nonschizophrenic paranoids, and nonpsychotic psychiatric patients were submitted to computerized content analysis. Speech samples were searched for words belonging to the Regressive Imagery Dictionary (Martindale, 1975), which yields a well-validated measure of primary process content. Three word-concreteness dictionaries were also employed. Compared to the other groups, paranoid schizophrenics produced speech higher in primary process content as well as in transitive verb concreteness. Results are consistent with psychoanalytic theory.

Adult↗
PubMed1986

Primary process cognition and hemispheric asymmetry.

Several theorists have hypothesized that the right hemisphere operates in a primary process manner, whereas the left hemisphere operates in a secondary process manner. Evidence for this hypothesis, though supportive, has been indirect. In two experiments, we applied a validated content-analytic measure of primary process cognition to verbal material produced by subjects while right-hemisphere and left-hemisphere alpha-wave amplitude was monitored. Both experiments indicated that amount of primary process content in language is related to basal or long-term hemispheric asymmetry (high levels of right-hemisphere activation, as compared to left-hemisphere activation), and that the relation with asymmetry is stronger than that with absolute levels of either right-hemisphere or left-hemisphere activation. Both experiments showed that primary process content is not closely related to momentary asymmetry. The second experiment indicated that within subjects, momentary asymmetry is in fact weakly related to primary process content in the direction opposite to that predicted.

Cognition↗
PubMed1984

Lexical differences between working and resistance sessions in psychoanalysis.

Divided 25 psychoanalytic sessions with a single patient into 10 working sessions, 5 neutral sessions, and 10 resistance sessions on the basis of ratings by psychoanalysts. Using the Regressive Imagery Dictionary on keypunched transcripts of these sessions, significantly more primary process content and less secondary process content was found in the patient's working-session speech, as opposed to resistance-session speech. Lexical diversity was also higher during working sessions. Results are compared with those obtained with other types of verbal material and are discussed in terms of psychoanalytic views on the process of psychotherapy.

Humans↗
PubMed1983

Psychological reality of cross-media artistic styles.

The sensitivity of artistically naive people to cross-media styles (baroque, neoclassic, and romantic) and to period styles (works composed by artists born during the same epoch) in four media (painting, poetry, music, and architecture) was assessed. In two studies, adult subjects tended spontaneously to sort stimuli according to both cross-media styles and period styles. In a third study, nursery school children were shown to be able to sort pictures of paintings and architectural facades on the basis of cross-media styles. Other experiments using rating scales again demonstrated that artistically naive adults are sensitive to both cross-media styles and period styles even when they are not implicitly urged to disregard medium. These and other studies using rating scales suggested that the bases for discrimination of both cross-media styles and period styles are the dimensions of realistic versus unrealistic and of overall arousal potential.

Architecture↗
PubMed1983

Marijuana-induced primary process content in the TAT.

Seventy-two normal adult male subjects wrote TAT stories under baseline and either placebo- or marijuana-ingestion conditions. Marijuana subjects received 20 mg. doses of delta-9 tetrahydrocannabinol. The stories were keypunched and content analyzed with the Regressive Imagery Dictionary, which yields a score for primary process content. Results indicate that marijuana, relative to placebo, caused subjects to write stories with a higher proportion of primary process content than they had included in baseline stories.

Adult↗
PubMed1982

Loxoscelism in the Transvaal, South Africa.

Bites by spiders of the genus Loxosceles have been implicated as a cause of necrotic arachnidism in the Transvaal. The identification and natural history of three species of Loxosceles common in the Transvaal, L. spinulosa, L. speluncarum and L. parrami, are discussed, the clinical symptoms of envenomation as observed both in human patients and in experimental animals are presented, and the histopathological appearance of the lesion, at different stages of its development, is described.

Animals↗
PubMed1980

Cutaneous necrosis caused by the bite of Chiracanthium spiders.

Spiders of the genus Chiracanthium are very common in and about homes in southern Africa. The bite of this spider results in cutaneous necrosis. The clinical and histopathological features and the natural history and identification of these spiders are discussed briefly.

Animals↗
PubMed1978

EEG differences as a function of creativity, stage of the creative process, and effort to be original.

Results of two experiments examining the relationship between creativity and EEG alpha wave presence are reported. In Experiment 1, it was found that more creative subjects exhibited higher alpha indices during an analogue of creative inspiration than during an analogue of creative elaboration. This pattern was not found in less creative subjects. In Experiment 2 a similar effect was found in a more controlled setting and shown to be specific to creative subjects when they are instructed to be original but not when they are given no such instructions. No consistent relationship between creativity and basal EEG alpha activity was found.

Alpha Rhythm↗