Biomedical subjects

R D Shindledecker

Publications and source records attributed to R D Shindledecker.

13 recordsLinked to original sources

PubMed1992

Pain perception in self-injurious patients with borderline personality disorder.

Pain ratings during the cold pressor test were significantly lower in female inpatients with borderline personality disorder who report that they do not experience pain during self-injury (BPD-NP group, n = 11), compared with similar patients who report that they do experience pain during self-injury (BPD-P group, n = 11), and normal female subjects (n = 6). Pain ratings were not significantly different in the BPD-P and normal control groups. Self-report ratings of depression, anger, anxiety, and confusion were significantly lower, and ratings of vigor significantly higher following the cold pressor test in the BPD-NP group, but not in the BPD-P group. Only anxiety was significantly lower in the normal control group following the cold pressor test. The implications and limitations of these preliminary findings are discussed.

Adolescent↗

PubMed1992

Brain computed tomography findings in geriatric depression and primary degenerative dementia.

Brain computed tomography (CT) scans were performed in hospitalized geriatric patients with major depression (n = 45) or primary degenerative dementia (n = 21). Depressed patients with onset of illness at age 60 years or older (n = 32) had greater ventricular size than geriatric depressives with earlier age of illness onset (n = 13). CT parameters of late-onset depressives were comparable to those of patients with primary degenerative dementia. However, early-onset geriatric depressives had significantly smaller ventricles and less sulcal widening than demented patients. The findings suggest that late-onset depression may have a stronger association with neurological dementing disorders than early-onset depression.

Aged↗

PubMed1992

Intake of different concentrations of sucrose and corn oil in preweanling rats.

To investigate the orosensory control of ingestion in preweanling rats, we infused one of the following liquids continuously through anterior sublingual intraoral catheters for 20 min: sucrose solutions (5, 10, 20, and 40%) and corn oil emulsions (6.25, 12.5, 25, 50, and 100%). Pups were tested at 7, 14, 21, and 28 days of age. Each pup was tested only once. Intake of sucrose and of corn oil became increasingly correlated with concentration from 7 to 21 days. Sucrose elicited more intake than water by day 7, whereas corn oil did not until day 14. Low concentrations of sucrose had differential effects on intake by day 14, but low concentrations of corn oil emulsions did not have differential effects on intake until day 21. At all ages, the peak intake of sucrose was significantly larger than the peak intake of corn oil. These differences are probably not based on prior experience because each test of ingestion represented a first exposure to the stimulus. Thus we suggest that the differences are due to the maturation of the orosensory control of ingestion by sucrose and corn oil.

Aging↗

PubMed1991

Verbal memory and plasma drug concentrations in elderly depressives treated with nortriptyline.

Performance on a verbal memory task and affective state were assessed in geriatric major depressives before and during 6 weeks of treatment with nortriptyline (NT) in a fixed-dose design study. Higher plasma NT concentration was associated with poorer free recall but better affective outcome. In contrast, higher plasma Z-10-hydroxynortriptyline (Z-10-OH-NT) concentration was associated with more efficient free recall. Concentration-effect relationships were noted in patients later classified as cognitively unimpaired using the Dementia Rating Scale after optimal treatment, rather than in those with residual cognitive impairment.

Aged↗

PubMed1990

Plasma tryptophan to large neutral amino acid ratios in depressed and normal subjects.

The ratios of total and free plasma tryptophan to the sum of five large neutral amino acids (LNAAs) were found to be significantly lower in a group of 16 depressed inpatients compared to nine normal subjects after oral loading with L-tryptophan. The group differences in these ratios were significant before, and 2 weeks after starting treatment with a tricyclic antidepressant. Plasma tryptophan ratios and severity of depression were not significantly correlated.

Adolescent↗

PubMed1989

Early experience and maternal behavior in rats.

This study examined the effects of early experience (early weaning with group housing in sibling groups (EG), or early weaning plus social isolation (EI) from 14 to 24 days of age) on maternal, play, and social behaviors expressed during 5 days of sensitization at 24 days, and then later at 100 days of age. Our results showed that maternal behaviors at 24 days could be altered by these early experiences. At 24 days of age fewer EI animals retrieved compared with normally weaned controls (NW), but more showed play behavior in the presence of pups. EG animals showed intermediate levels of retrieving relative to NW controls, and no concomitant changes in play behaviors. When retested as adults, females in all groups showed similar levels of all maternal behaviors. But EI adults of both sexes showed persistent intrusion of play behaviors, and higher levels of rearing and undirected activity in the presence of neonates. Factor analyses revealed that previously sensitized adult males showed patterns of organization of maternal behaviors that resembled adult females rather than those shown by control males reared without sensitization experience. Previously sensitized females also showed a retention of the play behavior patterns characteristic of juveniles, not present in females without sensitization experience. These results show that social experience during the weaning period can affect the development of maternal and play behavior elicited by neonates during the juvenile period that persist into adulthood, and the juvenile sensitization experience exerts longterm effects on adult patterns of maternal behavior in both sexes.

Animals↗

PubMed1989

Spectral analysis of cyclic symptoms in late luteal phase dysphoric disorder.

Fifty-eight subjects self-referred for premenstrual difficulty were evaluated for late luteal phase dysphoric disorder through a spectral analysis technique applied to prospective symptom ratings. Data from the Schedule for Affective Disorders and Schizophrenia--Life-time Version were used to group the subjects according to the absence or presence of past or present psychiatric disorders. The two psychiatric groups were compared with regard to both patterns of significant symptom change and premenstrual symptom severity. Differences between the groups are used to discuss issues regarding the reliable identification of late luteal phase dysphoric disorder and the impact of other psychiatric disorders on this syndrome.

Adult↗

PubMed1988

Premature maternal separation and lymphocyte function.

Premature separation of rat pups from their mothers, on postnatal Day 15, produced a decreased response of peripheral blood lymphocytes to phytohemagglutinin (PHA) at 40 days of age. A significant lymphopenia was also found in the early weaned animals at 40 days of age although this was accounted for statistically by their lower body weight. These consequences of early maternal separation may have been mediated through the effects of early separation on nutritional state, hypothalamic function, or maturation of the immune system.

Animals↗

PubMed1987

Chronobiologic factors in experimental stress ulcer.

The available literature on chronobiologic factors in experimental stress ulcer is extremely small and thematically limited. It focuses almost exclusively on circadian rhythms and, within that, on rhythms related to light-dark cycles, activity and body temperature. Among these, only differences in ulcer induction related to circadian activity patterns have been adequately demonstrated. Other circadian patterns and other temporal phase relationships might be profitably explored, including those related to postnatal development. It is also likely that the important relationships between biorhythms and stress ulcer are not limited to ulcer induction. Future studies should address chronobiologic factors in predisposition, severity of illness, the probability of recovery and response to various therapeutic interventions.

Age Factors↗

PubMed1987

Behavioral responses of juvenile rats (Rattus norvegicus) to neonates after infusion of maternal blood plasma.

Individual 18- or 30-day-old male and female Wistar rats (juveniles) were continuously exposed to 3-8-day-old pups for 5 days (sensitization) after intravenous (iv) infusion of maternal blood plasma (PL group) or 5% dextrose and water (IC group) through chronically implanted cannulas and were compared with nonhandled littermate controls (NHC group). The results showed complex interactions with sex and age of the animals tested, depending upon which maternal behaviors were examined. First, plasma from parturient females selectively increased retrieving behavior in 30-day-olds, and it was more powerful in females than in males. Second, on the first day, prior to sensitization, both PL and IC 30-day-olds showed higher frequencies of retrieving, crouching, anogenital licking, and contact than did nonhandled juveniles. Third, 30-day-olds that received maternal blood plasma continued to retrieve pups, with a latency peak for retrieving occurring at 72 hours, suggesting a long-term effect of plasma not seen in control animals. Fourth, 18-day-old subjects did not generally show effects of any of our manipulations, but they did show more nest building and contact behaviors than did 30-day-old subjects. Last, we found that the iv cannulation and infusion procedures led to a persistent dissociation of retrieving behavior from play in older animals and an integration of retrieving with crouching and licking regardless of whether maternal plasma or control infusion was administered. Retrieving behavior was associated with play behaviors (charge and pounce) in younger juveniles and in older, nonhandled control animals irrespective of treatment. For these animals, no integration of retrieving occurred with other maternal behaviors.

Animals↗

PubMed1986

Ontogeny of gastric secretion in the rat. Ultrastructural changes in relation to secretory changes.

Basal and stimulated gastric acid secretion are three to four times greater in the juvenile (30-day-old) rat than in the adult (100-day-old) rat, even though the parietal cell mass is greater in the adult. In this study we examined the possibility that the H+ secretory activity of individual parietal cells is greater in juvenile rats. To do this we used quantitative measures of secretory canaliculi and tubulovesicles as indirect measures of parietal cell H+ secretory activity. We determined that, under the experimental conditions used, the morphologic measures bear a sufficiently close linear relationship to total gastric H+ output to justify their use. We then found that when individual parietal cells from 30-day-old rats are compared quantitatively with those from 100-day-old rats, each cell from the younger rats has, on average, significantly more of the morphologic characteristics associated with higher H+ output. We inferred that individual parietal cells of 30-day-old rats, on average, may be secreting more H+ than corresponding cells of 100-day-old rats under comparable stimulation conditions.

Aging↗

PubMed1985

Development of maternal behaviors in prepubertal rats at three ages: age-characteristic patterns of responses.

Individual 18-, 24-, or 30-day-old male and female Wistar prepubertal rats (juveniles) were continuously exposed to 3-8-day old pups in order to determine developmental differences in the expression of maternal and other behaviors during the process of sensitization. The results that emerged from this study are as follows: Maternal behaviors are neither consistent nor integrated in their expression prepubertally; exposure to pups facilitates the emergence of some maternal behaviors in juveniles more easily than others, e.g., retrieving and anogenital licking more than ventral crouching or nestbuilding; there are age-related differences in the expression of different maternal behaviors, e.g., 24-day-olds retrieve more than at other ages; in our strain, few, if any, gender differences are apparent in the expression of maternal behaviors prepubertally; juvenile play behaviors (charge, pounce) are related to retrieving behavior in the context of exposure to pups. Overall, the results suggest that maternal behaviors are distinct developmentally and probably involve different mechanisms in prepubertal animals.

Age Factors↗

PubMed1984

Maturational increases and decreases in acid secretion in the rat.

We compared basal acid output (BAO) and maximally stimulated acid output (MAO) in 15-, 30-, and 100-day-old anesthetized rats. At each age we measured BAO and MAO in response to six different stimuli, pentagastrin (120 micrograms X kg-1 X h-1), bethanechol (1 mg X kg-1 X h-1), histamine (8 mg X kg-1 X h-1), the H2-receptor agonist impromidine (0.9 mumol X kg-1 X h-1), hypothermia (30 +/- 2 degrees C core temperature), and pyloric ligation, and we determined H+ output by continuous perfusion of the gastric lumen of anesthetized rats. Both weight-adjusted and absolute BAO were significantly greater in 30-day-old rats than in 15- or 100-day-old rats. Although 30-day-old rats had only one-fourth the fundic mass of 100-day-old rats, they could secrete two to three times more H+ per hour. These differences in MAO persisted even after subtracting BAO. Anatomic data indicate that these age-related changes do not correspond to changes in mucosal mass or parietal cell mass.

Acids↗