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Biomedical subjects

T Stewart

Publications and source records attributed to T Stewart.

At least 91 records · Page 5Linked to original sources

Correlation of stress with outcome of radioiodine therapy for Graves' disease.

Between November 1965 and December 1983, 293 patients were treated for Graves' disease using 131I. All patients were asked to identify a stressful event antedating the onset of overt clinical symptoms. Eighty-one patients were able to do this (27.6%). Six patients were lost to follow-up, the others were followed from 1 to 155 mo. Two hundred forty-four patients received a single treatment, 49 required two or more treatments. Stress and nonstress individuals were consistent with respect to age, sex, number of treatments and the dose of radioiodine. Patients with stress initiating the symptoms of Graves' disease became hypothyroid earlier, 50% at 12 mo compared with 36 mo for the nonstress group, p = 0.01. At 10 yr 5% of the stress group remained euthyroid compared with 17% nonstress. We conclude that stress in the 12 mo or less before the onset of clinical symptoms potentiates the development of hypothyroidism induced by a standard dose of radioiodine.

Adolescent↗

Grief in chronic illness: assessment and management.

Grief is a normal reaction to the loss of physical function. Its symptoms, however, are often mistaken for major depressive episode and treatment may be inappropriate. Symptoms of grief include a preoccupation with the lost object (a limb, a function, a loved one), somatic distress, inappropriate behavior, hostility, and denial. Depression may be a manifestation of illness or drug therapy. Grief should be treated like a major depressive episode but without antidepressive medications. The first step in management of grief is the development of a proper therapeutic milieu which will encourage the reappearance of self worth. Once the milieu is established, specific rehabilitation problems can be addressed. In formulating a prognosis, it is important to consider the severity of the patient's disability, the premorbid psychologic make-up, and the type of family and community support available to the patient.

Chronic Disease↗

Subcellular distribution of cyclic adenosine 3':5'-monophosphate-dependent protein kinase during the chemically induced differentiation of HL-60 cells.

In order to determine if cyclic adenosine 3':5'-monophosphate- (cyclic AMP)-dependent protein kinase has a role in the expression of chemically induced differentiation of HL-60 cells, levels and subcellular distribution of this enzyme were studied during this process. Cyclic AMP binding protein and stimulated kinase activities increased moderately in cytosol and more markedly in nucleosol and nonhistone chromatin-associated protein fractions of cells induced to differentiate with dimethyl sulfoxide or 12-O-tetradecanoylphorbol-13-acetate. Retinoic acid induced similar cytosolic changes but less marked intranuclear increases. Nuclear increases did not occur in the differentiation-resistant subline, HL-60 Blast II, treated with dimethyl sulfoxide. DEAE-cellulose chromatography, as well as photoaffinity labeling and gel electrophoresis, disclosed higher ratios of type I to type II kinase in cytosol than in intranuclear fractions. Differences of the qualitative binding protein patterns between cytosol and nucleosol were enhanced following chemically induced differentiation. Dibutyryl cyclic AMP increased cytoplasmic and nuclear binding protein levels when given alone or in combination with retinoic acid or dimethyl sulfoxide, and it enhanced differentiation. These results suggest that intranuclear cyclic AMP-dependent protein kinase is associated with the expression of the differentiative program in HL-60 cells.

Bucladesine↗

Translocations among antibody genes in human cancer.

The characteristic chromosomal translocations that occur in certain human malignancies offer opportunities to understand how two gene systems can affect one another when they are accidentally juxtaposed. In the case of Burkitt lymphoma, such a translocation joins the cellular oncogene, c-myc, to a region encoding one of the immunoglobulin genes. In at least one example, the coding sequence of the rearranged c-myc gene is identical to that of the normal gene, implying that the gene must be quantitatively, rather than qualitatively, altered in its expression if it is to play a role in transformation. One might expect to find the rearranged c-myc gene in a configuration that would allow it to take advantage of one of the known immunoglobulin promoters or enhancer elements. However, the rearranged c-myc gene is often placed so that it can utilize neither of these structures. Since the level of c-myc messenger RNA is often elevated in Burkitt cells, the translocation may lead to a deregulation of the c-myc gene. Further, since the normal allele in a Burkitt cell is often transcriptionally silent in the presence of a rearranged allele, a model for c-myc regulation is suggested that involves a trans-acting negative control element that might use as its target a highly conserved portion of the c-myc gene encoding two discrete transcriptional promoters.

Base Sequence↗

The human c-myc oncogene: structural consequences of translocation into the IgH locus in Burkitt lymphoma.

We have determined the sequence of the normal human c-myc gene and compared it to portions of a c-myc gene that has been translocated into the immunoglobulin heavy chain locus in a Burkitt lymphoma cell. The normal c-myc gene is encoded in three discrete exons divided by two large intervening sequences. Its mRNA is transcribed from two active promoters located about 150 nucleotides from one another. Each promoter initiates transcription of a long (approximately 550 bp) untranslatable leader sequence encoding the entire first exon. This exon and additional 5' flanking sequences are tightly conserved between mouse and man. In the Burkitt cell BL22, the rearranged c-myc gene retains both promoters and is unchanged in its amino acid coding domains. Translocation of this gene joins it to the immunoglobulin heavy chain switch region at a point approximately 1000 bp 5' to the dual c-myc promoters. These genes are joined in opposite transcriptional orientation. The structure of the translocated gene and the nature of its linkage to the immunoglobulin locus and the presence of two c-myc promoters and consequently two long leader sequences raise novel possibilities for the activation of an oncogene.

Amino Acid Sequence↗

Tobacco smoke xenobiotic compound appearance in mothers' milk after involuntary smoke exposures. I. Nicotine and cotinine.

In the development of the extraction procedure for the analysis of nicotine and cotinine from a single breast milk sample, nicotine and cotinine were detected in 3 of 10 nonsmoking mothers' milk samples. Interviews of these women revealed the presence of nonsmoking husbands and households but of tobacco smoke exposures during the working day. Clinically these levels may be considered inconsequential in regard to the threat to the mother and nursing infant but may be important in studies designed to monitor tobacco smoke xenobiotic compound appearance in breast milk.

Cotinine↗

Identification of medical student problems and comparison with those of other students.

The perceived problems of 585 medical students were compared with those of 1,110 students in the other health sciences colleges at the same institution. Through the use of a 5-point Likert scale, the students were able to indicate the degree to which each of 83 problem items on an inventory was of concern to them. The inventory included items concerning problems with life situation and school environment, other people, behavior, and feelings. The medical students were found to have the same spectrum of perceived problems as the other students but complained of these problems significantly more intensely on 35 items. Married students as a group responded to the problem items with significantly less intensity than the single students. Analyses of subgroups by marital status, gender, age, and year in school are also reported.

Adaptation, Psychological↗

A Navajo health consumer survey.

The findings of a health consumer survey of 309 Navajo families in three areas of the Navajo Reservation are reported. The survey shows that access to facilities and lack of safe water and sanitary supplies are continuing problems for these families. The families show consistent use of Indian Health Service providers, particularly nurses, pharmacists and physicians, as well as traditional Navajo medicine practitioners. Only incidental utilization of private medical services is reported. Extended waiting times and translation from English to Navajo are major concerns in their contacts with providers. A surprisingly high availability of third-party insurance is noted. Comparisons are made between this data base and selected national and regional surveys, and with family surveys from other groups assumed to be disadvantaged in obtaining health care. The comparisons indicate somewhat lower utilization rates and more problems in access to care for this Navajo sample. The discussion suggests that attitudes regarding free health care eventually may be a factor for Navajo people and other groups, that cultural considerations are often ignored or accepted as truisms in delivering care, and that the Navajo Reservation may serve as a unique microcosm of health care in the U.S.

Adolescent↗

The effect of immunosuppressive chemotherapy on immune function in patients with malignant disease.

This paper reviews studies previously conducted on the effect of anticancer drugs on immune function in man. It provides new data reporting on the effect of short intensive courses of cytotoxic drug therapy on B-lymphocyte and T-lymphocyte number in cancer patients. Both types of lymphocyte were found in this investigation to be equally sensitive to cytotoxic drugs. The degree of absolute cell number reduction and rate of recovery were similar for T-lymphocytes and B-lymphocytes. Other workers have demonstrated, however, that with prolonged administration of cytotoxic drugs B-lymphocyte number and function are more adversely affected than are T-lymphocyte number and function. Immune function which had been suppressed by continuous programs of chemotherapy for periods of up to 2-3 years will, in certain groups of patients, recover to normal or almost normal levels of function. Short courses of combination drug chemotherapy may be followed by "rebound-overshoot" recovery of immune function. This has been associated with a more favorable clinical course than in situations where it does not occur. Chemotherapy and chemoimmunotherapy programs in clinical oncology ought ideally to be initially evaluated for the effect that they have on immune function. This will permit the development of drug dose and time schedules which allow for recovery of immune function and may possibly lead to augmented antitumor responses.

Antibody Formation↗