Search PubMed⌕ Search

Biomedical subjects

C A Williams

Publications and source records attributed to C A Williams.

At least 127 records · Page 7Linked to original sources
PubMed1990

Transforming growth factor-beta 1 stimulates fibronectin production in bovine adrenocortical cells in culture.

Transforming growth factor-beta (TGF-beta 1) suppresses cortisol production when added to cultured bovine adrenocortical (BAC) cells while concomitantly increasing fibronectin synthesis and assembly into extracellular fibrils. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of gelatin-Sepharose-treated media from BAC cells demonstrated a 2-fold stimulation of fibronectin production by TGF-beta 1 in both the presence and absence of serum. Indirect immunofluorescence studies revealed that TGF-beta 1 caused a striking increase in the fibronectin content of BAC extracellular matrix. TGF-beta 1 caused a 4-fold increase in deoxycholate-insoluble fibronectin after 12 h and a 7-fold increase after 24 h over that of control BAC cultures. Northern hybridization analyses indicated that TGF-beta 1 stimulated levels of fibronectin poly(A)+ RNA 2.3-fold. We found that cultured BAC cells express TGF-beta 1 mRNA, suggesting a possible autocrine role for TGF-beta 1 in the adrenal.

Adrenal Cortex↗
PubMed1990

Maternal origin of 15q11-13 deletions in Angelman syndrome suggests a role for genomic imprinting.

Six persons with the classical Angelman syndrome (AS) phenotype and de novo deletions of chromosome 15q11-q13 were studied to determine the parental origin of the chromosome deletion. Four of the 6 patients had informative cytogenetic studies and all demonstrated maternal inheritance of the deletion. These findings, together with other reported cases of the origin of the chromosome 15 deletion in AS, suggest that deletion of the maternally contributed chromosome leads to the AS phenotype. This contrasts with the Prader-Willi syndrome (PWS) in which a similar deletion of the paternally contributed chromosome 15 is observed. In deletion cases, a parental gamete effect such as genomic imprinting may be the best model to explain why apparently identical 15q11-q13 deletions may develop the different phenotypes of AS or PWS.

Chromosome Deletion↗
PubMed1990

Clinical, cytogenetic, and molecular evaluation of a patient with partial trisomy 21 (21q11-q22) lacking the classical Down syndrome phenotype.

The clinical, cytogenetic, and molecular studies of an individual are presented here for the purpose of further characterizing what regions of chromosome 21q are essential for expression of the typical Down syndrome phenotype. This individual had a de novo, unbalanced translocation chromosome interpreted as: 45,XX,t(18;dup[21q]). Physical examination revealed mild manifestations, but not the typical phenotype of Down syndrome. The patient was studied using 20 single copy probes known to map to the 21q region. DNA polymorphism and dosage analyses showed triplication of loci D21S13 through D21S58 involving 21q11 to 21q22.1, and possibly involving the 21q22.2 region. Her clinical presentation, which did not include the classical findings of Down syndrome, suggests that regions distal to 21q22.1, when present in triplicate dose, account for the major manifestations of the classical phenotype. However, duplication of the area between the centromere and 21q22.1 may contribute to some of the other abnormalities in Down syndrome.

Adult↗
PubMed1990

Relationship of autoimmunity to thyroid dysfunction in children and adults with Down syndrome.

The extent to which autoimmunity contributes to thyroid dysfunction in Down Syndrome (DS) individuals has not been clarified. We studied 61 persons (34 males and 27 females) with DS (age 5 months to 48 years) for the presence of thyroid autoantibodies (thyroid microsomal antibodies and thyroglobulin antibodies), pancreatic islet cell autoantibodies, gastric parietal cell autoantibodies, and adrenocortical autoantibodies. Thyroid function was determined by measurement of TSH. HLA-A, B and -DR typing was performed on 52 subjects. Forty of 61 subjects (66%) had thyroid dysfunction: elevated TSH values (greater than 5 mcIU/ml) were found in 35 of 61 individuals; 3 subjects had previously documented Hashimoto thyroiditis and were on therapy for hyperthyroidism; and 2 persons had Graves disease. No age or sex variation was detected. Seventeen (28%) subjects had thyroid autoantibodies. Fifteen of the 17 had thyroid dysfunction. Twelve of 25 subjects (48%) over 10 years with thyroid dysfunction had thyroid autoantibodies compared to only 3 of 15 (20%) under the age of 10 years. However, children less than of 10 years tended to have higher TSH values. Only 1 individual who had thyroid antibodies had gastric parietal cell autoantibodies present. Islet cell and adrenocortical autoantibodies were not found in any individuals. Neither thyroid dysfunction nor thyroid autoantibodies correlated with any HLA allele. These findings suggest that thyroid dysfunction in individuals with DS of all ages is a common heterogeneous disorder which cannot be solely explained on the basis of autoimmunity. We recommend that thyroid function be followed closely whether or not thyroid autoantibodies are present.

Adolescent↗
PubMed1990

HIV-associated periodontitis complicated by necrotizing stomatitis.

This report describes a case of HIV-associated periodontitis complicated by necrotizing stomatitis in a homosexual male patient with AIDS. Necrotizing stomatitis is a rapidly progressive ulcerative and necrotic infection that causes massive destruction of the oral tissues and underlying bone. Like HIV periodontitis, it appears to be related to the immune suppression caused by human immunodeficiency virus (HIV) infection; importantly, it may be life threatening. In this case, initial resolution resulted from local debridement in association with metronidazole therapy. Long-term clinical management consisted of monthly professional prophylaxis, good oral hygiene, and daily rinses with chlorhexidine. This case suggests that progressive oral necrotizing infection should be recognized as one element in the spectrum of oral manifestations of HIV infection.

Acquired Immunodeficiency Syndrome↗
PubMed1990

The nature of clinical supervision in psychiatric nursing: a survey of clinical specialists.

There is a growing body of theory and research on clinical supervision within other mental health disciplines; however, there has been little study of clinical supervision within psychiatric mental health nursing. This article reports the results of a survey of 61 psychiatric mental health specialists to determine their attitudes toward selected supervisory issues. Two-thirds of the respondents had received further supervision beyond the master's degree, one-half reported a personal psychotherapy experience, and one-half were certified in psychiatric mental health nursing. There were significant differences of opinion between clinical nurse specialists who were certified and those who were not and between those who reported a personal therapy experience and those who did not. The authors suggest that more attention be paid to the development of curriculum content regarding clinical supervision in graduate nursing programs. In addition, they recommend further research on the topic of clinical supervision in psychiatric mental health nursing.

Adult↗
PubMed1990

Changes in blood pressure during isometric contractions to fatigue in the cat after brain stem lesions: effects of clonidine.

STUDY OBJECTIVE: The aim was to determine whether areas in the periaqueductal grey matter, medial dorsal raphe, or ventrolateral medulla might be involved with the integration of blood pressure and heart rate during isometric exercise. DESIGN: Cats were anaesthetised with alpha chloralose (75 mg.kg-1) and catheters inserted into the right jugular vein and carotid artery. Isometric contractions were generated using a microprocessor controlled stimulator and sleeve electrode around the tibial nerve. Bilateral lesions were made in the dorsal periaqueductal grey matter (P1.0, LR2.0, HD + 1.5 mm) or two sites in the ventrolateral medulla (P12.0, RL 2.0, HD -10 mm; or P12.0, RL 2.0, HD -8.5 mm). Lesions were also made in the medial dorsal raphé nuclei (P1.0, RL 0.0, HD +1.5 mm). Clonidine was injected into the cerebral aqueduct to determine whether it would exert an antipressor effect during muscle contraction after the lesions were made. Only one site of lesion was made in a group of animals. Bilateral injections of clonidine (250 ng in 0.5 microliter) were made into the intact ventrolateral medulla (P11.5, RL 4.0, HD -8.5 mm) to explore its role further. Fatiguing contractions were performed before and after the lesions were made, or clonidine was injected, and changes in arterial blood pressure and heart rate were measured. Verification of the lesion sites or the microinjection sites, and the extent of the lesion or spread of the clonidine, was made from histological examination of brain tissue after each experiment. EXPERIMENTAL MATERIAL: Adult cats of either sex, n = 20, weight 2.4 (SD 0.4) kg, were used. MEASUREMENTS AND MAIN RESULTS: Fatiguing isometric contractions in control conditions caused mean arterial pressure to increase by 45-50 mm Hg and heart rates by 20-25 beats.min-1. Bilateral lesions in the dorsal periaqueductal grey matter did not alter resting mean arterial pressure but attenuated the pressor response during contractions. Injections of clonidine into the cerebral aqueduct had no further antipressor effects after the lesions. Lesions of the medial dorsal raphé nuclei or injections of clonidine into the intact medial dorsal raphé nuclei did not affect the pressor response to fatiguing isometric contractions. Injections of clonidine into the intact ventrolateral medulla eliminated the pressor response to isometric contractions. Bilateral lesions of the ventrolateral medulla near the rostral lateral border of the inferior olivary tract nuclei (P12.0, LR 2.0, HD -10 mm) also attenuated the muscle pressor response, while subsequent injections of clonidine into the cerebral aqueduct depressed the changes in blood pressure further. CONCLUSIONS: Ergoreceptor information may be processed through the periaqueductal grey matter through the ventrolateral medulla to control arterial blood pressure during isometric exercise to fatigue.

Animals↗
PubMed1990

Biopsychosocial elements of empathy: a multidimensional model.

Empathy is a topic of growing concern in a variety of disciplines. Although considerable empathy research is reported, often single dimensions of a multidimensional and multiphasic construct are actually being studied. Empathy is a unitary construct involving biopsychosocial components and is particularly well suited for nursing study because of its theoretical congruence with nursing philosophy and concerns. Empathy's importance goes beyond the usual emphasis on helper empathy. Although commonly associated with prosocial behavior, empathy involves underlying processes which may be used for either positive or negative social purposes. Recent technological improvements in research methodology, concerns regarding social violence, and conceptual shifts have led to greatly increased interest in the phenomenon of empathy and an expanded research thrust. One major recent change in empathy research is the tendency to view the phenomenon as multidimensional and consequently to include a variety of measures to capture different elements of the construct. This paper reviews the major approaches to measurement of empathy and classifies these approaches according to the dimensions of empathy that they measure. Physiological change in association with empathy is less frequently measured, but because empathy is commonly assumed to include an emotional response to another, concomitant physiological changes should accompany the emotional aspect of empathy and indicators of physiological response may be appropriate measures to include in nursing studies of empathy. A conceptualization of empathy is presented that considers empathy to be a multidimensional phenomenon, with emotional, cognitive, communicative, and relational components. Because empirical approaches can only examine the most easily measured aspects of empathy, phenomenological approaches are also needed to begin to capture the total construct.

Cognition↗
PubMed1990

ATP-activated channels in rat and bullfrog sensory neurons: current-voltage relation and single-channel behavior.

Ionic currents activated by extracellular adenosine 5'-triphosphate (ATP) were studied in voltage-clamped dorsal root ganglion neurons from rats and bullfrogs. Under quasiphysiological ionic conditions, ATP-activated current reversed near 0 mV and showed strong inward rectification. Strong inward rectification was maintained even in symmetric solutions of divalent-free Cs glutamate. Examined with a resolution of 10s of microseconds, the rectification was instantaneous. Inward current was greatly reduced when N-methyl-D-glucamine was substituted for external Na. ATP-activated inward currents could be recorded with Ca as the only external cation; estimated from reversal potentials, the ratio of Ca to Na permeability is about 0.3. Unitary channel activity could be recorded when ATP was applied to outside-out patches. When activated, a single channel flickered rapidly, with a mean current of about 0.5 pA at -100 mV. Large concentrations of ATP put the channel in the activated, flickery condition virtually all the time, while at lower concentrations, periods of flickering were interspersed with closures. Analysis of whole-cell current fluctuations showed precisely the characteristics expected if such channels underlie the macroscopic currents.

Adenosine Triphosphate↗
PubMed1990

Cytogenetic survey for autistic fragile X carriers in a mental retardation center.

A cytogenetic survey of 67 individuals previously identified as having mental retardation and autistic behaviors revealed 1 person (1.5%) with the fragile X chromosome (fra[X]) and 3 (4.5%) with autosome abnormalities. This low prevalence of fra(X) indicates that most persons with fra(X) in this mental retardation center did not have autistic behaviors severe enough to be identified as a secondary psychiatric diagnosis. The presence of other chromosomal abnormalities is consistent with the known causal heterogeneity of autism in mental retardation populations.

Adult↗
PubMed1990

The effect of macromolecular rat serum fractions on conceptuses cultured in human serum: role of transferrin.

We describe the results of experiments to study the effects on rat conceptuses cultured in human serum supplemented with rat serum which was separated into high (greater than 30 kDa) and low (less than 30 kDa) molecular weight fractions by ultrafiltration. Ultrafiltered rat serum was found to lack certain growth-promoting substances which are necessary for embryonic growth and differentiation during the culture period. Culture in whole human serum or human serum supplemented with low molecular weight fraction (filtrate) results in conceptuses which grow reasonably well but are anaemic, whilst anaemia is relieved by the high molecular weight fraction. Addition of human or rat transferrin (MW 80 kD approx.) to whole human serum alleviates anaemia, an effect observed more distinctly with rat transferrin.

Anemia↗
PubMed1990

Identification of patients at risk for gastropathy associated with NSAID use.

It is suggested that gastropathy associated with nonsteroidal antiinflammatory drugs (NSAID) is the most frequent and, in aggregate, the most severe drug side effect in the United States. This work is based on a consecutive series of 2,400 patients with rheumatoid arthritis (RA) followed prospectively for an average of 3.5 years by the American Rheumatism Association Medical Information System. We present a preliminary exploration of the magnitude of the problem, the population at risk and the patients within that population who are at particularly high risk. Patients on NSAID had a hazard ratio for gastrointestinal (GI) hospitalization that was 6.45 times that of patients not on NSAID. Characteristically, patients at high risk for GI hospitalization and GI death are older, have had previous upper abdominal pain, have previously stopped NSAID due to GI side effects and have previously used antacids or histamine2-receptor antagonists for GI side effects. These patients also frequently take corticosteroids. Patients attributing relatively minor symptoms to NSAID tend to be younger and female. Our preliminary analysis is univariate; since these variables are interdependent, firm conclusions regarding the relative importance of these risk factors require development of multivariate risk factor models. The syndrome of NSAID-associated gastropathy can be estimated to account for at least 2,600 deaths and 20,000 hospitalizations each year in patients with RA alone.

Adult↗
PubMed1989

Angelman syndrome in a daughter with del(15) (q11q13) associated with brachycephaly, hearing loss, enlarged foramen magnum, and ataxia in the mother.

We report on a 4-year-old girl with Angelman syndrome who has an apparent de-novo del(15) (q11q13) originating from a maternally derived chromosome. Her mother had severe brachycephaly, sensorineural hearing loss, speech impediment, and mild ataxia. CT brain scans showed an enlarged foramen magnum in the mother and daughter but magnetic resonance imaging (MRI) showed no brainstem abnormality in either. This family demonstrates that some Angelman syndrome cases may be dominantly transmitted with variable expression and associated with abnormal or cytogenetically apparently normal chromosome 15.

Adult↗
PubMed1989

Incidence of 15q deletions in the Angelman syndrome: a survey of twelve affected persons.

Prometaphase chromosome study of 12 persons with an established diagnosis of the Angelman syndrome demonstrated that 5 had a 15q12 deletion appearing similar to that commonly observed in the Prader-Willi syndrome. Phenotype-karyotype correlation did not show any obvious clinical differences between those with and those without the deletion and no clinical overlap between Angelman and Prader-Willi syndrome was apparent. Our survey suggests that 15q12 deletions are frequent in Angelman syndrome but presence of the deletion does not appear to distinguish different clinical phenotypes. Experience with the cytogenetic study of Prader-Willi syndrome predicts that considerable complexity will emerge between the presence of 15 chromosome abnormalities and clinical expression of Angelman syndrome.

Abnormalities, Multiple↗
PubMed1989

Empathy and burnout in male and female helping professionals.

Relationships between empathy and burnout and possible confounding influences of sex and profession were explored in a sample of 492 male and female nurses, social workers, and teachers. Respondents completed Mehrabian's Emotional Empathy Scale, Stotland's Fantasy-Empathy Scale, and the Maslach Burnout Inventory (MBI). There were no main effects of profession on empathy or burnout variables. There was, however, an interaction effect of sex and profession on depersonalization, which was accounted for by subjects in social work and teaching. Women had significantly higher empathy scores than men; however, men had higher scores than male normative groups. Age related negatively to depersonalization and emotional exhaustion for women, whereas percentage of work time spent in direct practice correlated with depersonalization for men. The possibility that empathy and burnout might represent opposite poles of the same underlying construct was examined but not found. Instead, emotional empathy was significantly positively correlated with both emotional exhaustion and personal accomplishment, whereas emotional exhaustion was also positively related to depersonalization. It is hypothesized that high emotional empathy may predispose helping professionals to emotional exhaustion and that emotional exhaustion, if not mediated by personal accomplishment, may lead to the development of depersonalization. This more complex, interactive model of the empathy-burnout relationship needs longitudinal study.

Burnout, Professional↗
PubMed1989

Common problems and coping strategies. I: Findings with normal adolescents.

This study investigated problems commonly experienced by adolescents and the strategies they use to cope with these events. Coping strategies were examined across the subjects' emotional state and their evaluation of the problem. In general, adolescents reported four common stressors that were similar across age groups and gender. However, males differed from females in the frequency of these problems. Further, while the stressors were similar, the frequency with which the coping strategies were employed and the efficacy ascribed to them differed across sex and across problem type. These findings are discussed in terms of the stress and coping literature with adults and the implications for clinical assessment and treatment of adolescents.

Adaptation, Psychological↗