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Biomedical subjects

J A Jagielo

Publications and source records attributed to J A Jagielo.

6 recordsLinked to original sources
PubMed1991

Differential effectiveness of various prior-cuing treatments in the reactivation and maintenance of memory.

In 3 experiments, changes were examined in the characteristics of newly acquired and reinstated memories over time in preweanling rats. Experiment 1 indicated that forgetting after conditioning was monotonic, with the upper limit of retention at approximately 120 min posttraining. In Experiment 2, Ss were exposed to various elements of the training episode before testing, after either a 3- or a 24-hr retention interval. The results indicated that the prior-cuing treatments were differentially effective and that the effectiveness of a reactivation treatment may change as a function of the retention interval. Experiment 3 indicated that Ss expressed a conditioned aversion at much longer intervals following reactivation treatments than after initial conditioning. Furthermore the susceptibility of the reinstated memory to forgetting was dependent on the prior-cuing treatment used. The results suggest a change in the memorial representation of the conditioning episode over time.

Animals↗
PubMed1989

Age-related differences in short-term retention of separable elements of an odor aversion.

The rate of forgetting over short intervals was tested in preweanling rats, 8, 12, or 18 days postnatal, using procedures that may have analytical advantages over other tests of short-term retention. Separate tests of retention were conducted for the simple occurrence of an odor and for the occurrence of an odor paired with a mild footshock. Forgetting of odors with either of two histories, incidental or target, was more rapid the younger the preweanling, over intervals of less than an hour. There was some indication of more rapid forgetting for incidental than target odors. Finally, although exposure to a CS- (an odor not paired with footshock) was necessary for conditioning of the CS+ (an odor paired with footshock) in rats 8 or 12 days of age, exposure to a CS- had no influence on conditioning of the CS+ in preweanlings 18 days of age. The age-related differences in forgetting over intervals less than an hour long suggest that substantial age-related differences in forgetting can occur that, it is likely, are not accounted for by differential growth.

Aging↗
PubMed1986

Evaluation of urinary cytology of male sexual partners of women with cervical intraepithelial neoplasia and human papilloma virus infection.

Condylomas of the genital tract can be found in 70% of patients who have cytologic evidence of human papilloma virus (HPV) infection or mild epithelial dysplasia (CIN I). Most male sexual partners of women with overt or subclinical HPV infections have no visible condylomas. Presently, there is no therapy for subclinically infected male partners. A screening test capable of detecting such HPV infections in males would be of value should effective therapy be discovered. Fifty-four men who were the current sexual partners of women with visible condylomata acuminata or with cytologic evidence of subclinical HPV infection or cervical neoplasia were asked to give a urine specimen for cytologic examination. The cytologist had no knowledge of the cytologic or histopathologic findings in the female partners. Of the 54 women, 39 (72%) had either visible genital condylomas or cytologic evidence of mild dysplasia or of HPV infection with or without mild dysplasia (CIN I). Twenty-five (63%) had histologic evidence of HPV infection with or without mild dysplasia. With one exception, urinary cytologic preparations from the study and from the control males were negative. No correlation could be found between cervical cytology and histology in the females and urinary cytologic findings in their current male partners. At the present time there is no screening test that can be utilized to detect male carriers with subclinical disease.

Carrier State↗
PubMed1986

Categorical shape and color coding by pigeons.

Categorical coding is the tendency to respond similarly to discriminated stimuli. Past research indicates that pigeons can categorize colors according to at least three spectral regions. Two present experiments assessed the categorical coding of shapes and the existence of a higher order color category (all colors). Pigeons were trained on two independent tasks (matching-to-sample, and oddity-from-sample). One task involved red and a plus sign, the other a circle and green. On test trials one of the two comparison stimuli from one task was replaced by one of the stimuli from the other task. Differential performance based on which of the two stimuli from the other task was introduced suggested categorical coding rules. In Experiment 1 evidence for the categorical coding of sample shapes was found. Categorical color coding was also found; however, it was the comparison stimuli rather than the samples that were categorically coded. Experiment 2 replicated the categorical shape sample effect and ruled out the possibility that the particular colors used were responsible for the categorical coding of comparison stimuli. Overall, the results indicate that pigeons can develop categorical rules involving shapes and colors and that the color categories can be hierarchical.

Animals↗
PubMed1978

The effect of glucose on the biochemical and ultrastructural characteristics of developing Euglena chloroplasts.

Chloroplast development is inhibited in Euglena gracilis strain Z, when greened in a medium containing glucose. This inhibition is reflected not only in the pattern of chlorophyll accumulation but also in the chloroplast ultrastructure and activities of the 2 light reactions of photosynthesis. Chloroplasts of cells greening in the presence of glucose are delayed in developing certain structures. Photosystem I activity develops at about the same rate as that of the controls during the first 48 h of greening, after which it develops at a slower rate. The rate of development of photosystem II activity in cells greening in a glucose medium lags considerably behing that of the controls until the later hours of greening. There are similarities between glucose inhibition and chloramphenicol inhibition of chloroplast development. Glucose may inhibit a step in chloroplast development ultimately controlled by the chloroplast genome.

Chlorophyll↗