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Biomedical subjects

D Troyer

Publications and source records attributed to D Troyer.

At least 37 records · Page 2Linked to original sources
PubMed1994

The relations of children's emotion regulation to their vicarious emotional responses and comforting behaviors.

The purpose of the present study was to examine the relations of children's emotional and behavioral regulation (as indexed by heart rate variability and coping styles) to their emotional and prosocial responses to a crying infant. Kindergarten and second-grade children's vicarious emotional responses (e.g., facial reactions and heart rate slope) and comforting behaviors were recorded while children heard a crying infant. The mothers of these children completed a measure designed to assess their children's coping responses when exposed to others in distress. It was found that children who were able to regulate their arousal (as assessed with heart rate variance) and typically responded instrumentally when exposed to others' needy states and conditions were relatively unlikely to become distressed and relatively likely to talk to and comfort the crying infant. Compared to boys, girls were found to be more responsive to the crying infant and were reported to engage in more direct, active coping responses when exposed to others in distress. The results are discussed in relation to research on emotion regulation and coping in interpersonal contexts.

Adaptation, Psychological↗
PubMed1993

The relations of empathy-related emotions and maternal practices to children's comforting behavior.

Examined are the relations of maternal empathy-related characteristics, maternal child-rearing practices, and children's vicarious emotional responding to kindergarteners' and third graders' comforting of a crying infant. Children who exhibited facial personal distress in reaction to the baby cry were less likely to help than were other children. In addition, children's distressed reactions to a different sympathy stimulus (a film) were positively correlated with their distressed reaction to the baby cry; children's self-reported reactions to the sympathy-inducing film also were related to their comforting behavior. For girls, maternal perspective taking was positively related to amount and quality (tone of voice) of comforting behavior. Moreover, maternal use of problem-solving and discussion when their daughters were distressed or anxious were associated with higher levels of girls' helping whereas maternal comforting/affirming in a distressing context was negatively related to helping. The only relation of maternal variables to comforting for boys was a positive correlation between maternal reinforcement and quality of boys' comforting.

Child↗
PubMed1993

Skeletal muscle of cattle affected with progressive degenerative myeloencephalopathy.

Skeletal muscle from multiple sites of 6 cattle afflicted with progressive degenerative myeloencephalopathy was analyzed by transmission electron microscopy and compared with skeletal muscle taken from 2 clinically normal cattle (controls) similarly studied. Major changes in the affected muscle included abnormal myoneural junctions with redundant junctional folds that were abnormally long and branching, and occasionally separated from the synaptic site; multiple vacuoles of variable size clustered in subsarcolemmal positions and in rows between myofibrils; bizarre mitochondria with thin connecting stalks, large electron-dense bodies, and abnormal cristae; and cone-shaped projections of the sarcolemma. These findings indicate that myopathy is part of the progressive degenerative myeloencephalopathy phenotype.

Animals↗
PubMed1992

Stimulation of the thrombin receptor of human glomerular mesangial cells by Ser-Phe-Leu-Leu-Arg-Asn-Pro-Asn-Asp-Lys-Tyr-Glu-Pro-Phe peptide.

We have studied the effects of thrombin (alpha-thrombin) and Ser-Phe-Leu-Leu-Arg-Asn-Pro-Asn-Asp-Lys-Tyr-Glu-Pro-Phe (SFLL), a peptide agonist of the platelet thrombin receptor in cultured human mesangial cells, and find that SFLL can reproduce the biochemical and morphological effects of thrombin. Treatment of mesangial cells with cAMP-elevating agents causes fragmentation of stress fibers, loss of the vitronectin receptor from sites of focal adhesion, and produces a change in shape from a flat to a more arborized configuration. These effects are prevented by both thrombin and SFLL. Thrombin and SFLL also initiate biochemical signaling events in mesangial cells by stimulating the metabolism of phospholipids. Both thrombin and SFLL stimulate release of inositol phosphates from [3H]inositol-labeled cells, elevation of cytosolic calcium, the formation of [3H]myristic acid-labeled diacylglycerol, an increase in the mass of diacylglycerol, 32P incorporation into phospholipids, and release of unesterified [3H]arachidonic acid from cells prelabeled with [3H]arachidonic acid. When present together, the effects of SFLL and thrombin on diacylglycerol formation, arachidonic acid production, and inositol phosphate production were not additive. This suggested that SFLL and thrombin were acting on the same receptor. This was further supported by our observations that cells pretreated with SFLL and subsequently exposed to thrombin (or vice versa) did not show elevated cytosolic calcium. We also show that phospholipase D is activated by demonstrating production of radiolabeled phosphatidylethanol when cells are treated with SFLL in the presence of ethanol. These findings indicate that SFLL can be used to study the receptor-mediated effects of thrombin in mesangial cells, thereby avoiding thrombin's proteolytic actions.

Actins↗
PubMed1992

Upper motor neurone and descending tract pathology in bovine spinal muscular atrophy.

The extent of neuropathology in a recently reported disease of Brown Swiss cattle, spinal muscular atrophy (SMA), was investigated with light and electron microscopy. Many regions of the central nervous system were sampled from 10 SMA-affected and three normal Brown Swiss calves. In addition to extensive necrosis of lower motor neurones there was extensive upper motor neurone degeneration and descending tract pathology. Since these abnormalities are also hallmarks of amyotrophic lateral sclerosis (ALS), SMA may be an animal model for that disease. There was also considerable vacuolar degeneration, which is a feature of the wobbler mouse and murine type C RNA virus-induced paralytic disease models of ALS.

Animals↗
PubMed1992

Histochemical and morphometric studies of peripheral muscle in bovine progressive degenerative myeloencephalopathy of brown Swiss cattle.

Histochemical and morphometric analysis of selected skeletal muscles was performed on 14 pure bred, Brown Swiss cattle. Nine cattle were clinically affected with bovine progressive degenerative myeloencephalopathy (BPDME) while five served as controls. Statistically significant trend differences were not observed for the parameters of mean cross sectional area, and mean fiber type percentages for types, I, IIA, and IIB fibers between affected and control test groups. In general, patterns of hypertrophy or atrophy, fiber type grouping, fiber type predominance, or fiber cross sectional profile alteration were not observed in the muscles examined from affected cattle. The findings suggest that BPDME, or weaver syndrome, is not a muscular dystrophy and that muscle pathology is not a primary part of the syndrome nor would muscle pathology be expected to contribute significantly to the clinical signs of the disease.

Animals↗
PubMed1992

Electron microscopic studies of bovine progressive degenerative myeloencephalopathy in brown Swiss cattle.

Selected peripheral nerves from animals affected with Bovine Progressive Degenerative Myeloencephalopathy (BPDME) were examined by transmission electron microscopy. Changes in axons were both degenerative and reactive in nature and included axonal swelling in conjunction with accumulation of altered organelles and various forms of vesicles. Affected axoplasm was often vacuolated and shrunken, with loss of microtubules and microfilaments and separation of the axoplasmic membrane from the myelin sheath. Segmental disorganization of the normal lamellar pattern of myelin sheaths was observed. Affected myelin sheaths exhibited intramyelinic vacuoles or myelin bubbles often in association with concurrent axonal changes. Schwann cells occasionally contained swellen and vacuolated mitochondria and membrane-bound vesicles. Axonal and myelin changes were considered similar, if not identical, to those described in the central nervous system of affected animals reported in the literature. Collectively, the changes described in the axons and myelin sheaths of the peripheral nerves studied were considered to be compatible with the "dying back" process described in various distal axonopathies. A metabolic defect in the enzyme systems associated with axonal transport was postulated to explain these peripheral nerve lesions.

Animals↗
PubMed1992

An alternative bent-knee prosthesis.

Prosthetic fitting in patients with below-knee amputations and concurrent knee flexion contractures poses inherent difficulties to the prosthetic rehabilitation team. The standard bent-knee prosthesis is bulky and awkward. It treats the patient functionally as a knee disarticulation and yields no potential for improving the patient's degree of contracture. This paper describes a case report with an alternative to the bent-knee prosthesis that not only offered improved function relative to the standard bent-knee prosthesis, but also acted therapeutically by reducing the patient's knee-flexion contracture.

Amputation, Surgical↗
PubMed1992

The relations of maternal practices and characteristics to children's vicarious emotional responsiveness.

This study examined the relations of maternal vicarious emotional responding and child-rearing practices, as well as familial emotional environment, to 5-6 and 8-9-year-old children's vicarious emotional responding. There were some correspondences between mothers' and children's heart rate, facial, and self-reported reactions to a sympathy-inducing film. Maternal sympathy/perspective taking and reinforcement of sympathy/prosocial behavior, as well as negative subordinate emotion in the home, were associated with markers of girls' sympathy; mothers' personal distress (for girls), restrictiveness regarding displays of hurtful negative emotions (particularly for young girls), and negative dominant emotion in the home (for both sexes) were associated with markers of personal distress. Mothers' linking of the film character's experience to children's own experience was associated with children's responsiveness to the film, and mother's verbalizations during the film concerning her own emotional state and role taking were associated with boys' self-reported sympathy.

Arousal↗
PubMed1991

The altruistic personality: in what contexts is it apparent?

Hypotheses concerning the specific contexts in which an altruistic personality might be most apparent were investigated. College students completed questionnaires tapping components of an altruistic personality, emotionality, and social desirability. At a 2nd session, the emotional evocativeness and ease of escape from the helping situation were experimentally manipulated. Ss were exposed to a distressed woman, completed state sympathy and personal distress indexes, and were given an opportunity to assist the woman. High scorers on dispositional altruism were expected to assist most when escape was easy, particularly when the distress cues were obvious. Altruistic and emotionally reactive persons were also expected to help most in a psychologically "weak" environment. Both predictions were supported. The relations between helping and the other predictors were also examined.

Adolescent↗
PubMed1990

Undulin, an extracellular matrix glycoprotein associated with collagen fibrils.

Undulin, a novel noncollagenous extracellular matrix protein, was isolated from skin and placenta. In polyacrylamide gels most of the unreduced protein migrates with Mr above 1,000,000 yielding bands A (Mr 270,000), B1 (Mr 190,000), and B2 (Mr 180,000) after reduction. Undulin is biochemically and immunochemically distinct from other previously characterized large matrix glycoproteins. Immunoblotting using monoclonal antibodies suggests that bands A and B are closely related. Electron microscopy reveals undulin as structures consisting of an approximately 80-nm-long-tail with a nodule on one end and with one or two shorter arms on the other. Ultrastructurally immunolabeled undulin is found mainly between densely packed mature collagen fibrils. Indirect immunofluorescence shows bundles of uniform wavy fibers in dense connective tissues superimposable on a subpopulation of type I collagen structures. This suggests that undulin serves a specific yet unknown function in the supramolecular organization of collagen fibrils in soft tissues.

Amino Acids↗
PubMed1990

Physical activity and condition, dietary habits, and serum lipids in second-year medical students.

Level of physical activity has been found to be an independent risk factor for coronary heart disease. Because lifestyle and dietary habits are frequently established by early adulthood, we examined the physical activity, physical fitness, body composition, plasma lipids, and diets of a group of second-year medical students. Medical students were studied because of the presumption that they were knowledgeable about exercise and appropriate diet and would have future influence on their patients. A questionnaire which assessed physical activity was returned by 69 (89%) of the 80 students. Over 50% reported no hard or very hard physical activity either during the week or on weekends. Three subjects were smokers. Body composition, cardiovascular fitness, and plasma lipids were assessed in 20 subjects selected at random from the 69. Five of the 15 men, but none of the five women, had greater-than-desirable body fat. Cardiovascular fitness was at least average compared to normal values, but three had hypertension at rest and 12 had hypertensive responses to exercise. Seven of the men had LDL cholesterol above 130 mg/dl and three had LDL:HDL ratios greater than 3. There was a positive correlation (r = 0.5, p = 0.02) between hard/very hard activity assessed by questionnaire and VO2max and a negative correlation (r = 0.4, p = 0.05) between VO2max and percent fat. All 20 subjects reported above average to severe amounts of stress. Analysis of a 48-hr diet record of 22 students showed an average consumption of 47% carbohydrates, 17% protein, and 36% fat. The polyunsaturated/saturated ratio was 0.43.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

A human minisatellite sequence reveals DNA polymorphism in the equine species.

Southern blot analysis of equine DNA's digested with the restriction endonuclease Hinfl hybridized with a 32 PdCTP labeled human VNTR probe revealed a highly polymorphic pattern of restriction fragments upon autoradiography. The horses were unrelated individuals of the quarter horse breed. This heterologous probe can thus be used in the equine species for individual identification and pedigree analysis.

Animals↗
PubMed1988

Interaction of atrial natriuretic peptide-stimulated guanylate cyclase and vasopressin-stimulated calcium signaling pathways in the glomerular mesangial cell.

Receptors for atrial natriuretic peptide (ANP) have been demonstrated in renal mesangial cells as well as other cell types in the glomerulus. The biochemical basis for the effects of ANP on glomerular hemodynamics remains undefined. Using cultured rat glomerular mesangial cells, we demonstrated a concentration-dependent stimulation of cGMP production in intact cells, and of guanylate cyclase in membranes. Despite the presence of a guanylate cyclase response, ANP had no inhibitory effect on basal inositol trisphosphate production nor on basal cytosolic calcium. Arginine vasopressin stimulated IP3 production, caused a rise in cytosolic calcium as measured using the calcium-sensitive fluorescent probe Indo-1, and caused mesangial cell contraction. ANP caused a slight but significant enhancement of vasopressin-stimulated IP3 production, but had no effect on the cytosolic calcium response nor on the contractile response. 8-Bromo-cGMP likewise had no effect on the generation of the calcium signal. These results indicate that the effects of ANP on glomerular hemodynamics are not mediated by an alteration in the generation of the calcium signal in mesangial cells. In contrast, addition of calcium inhibited ANP stimulated guanylate cyclase activity.

1-Methyl-3-isobutylxanthine↗