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Biomedical subjects

J Hackney

Publications and source records attributed to J Hackney.

9 recordsLinked to original sources
PubMed2001

Eddies in the stream: the prevalence of uncertain plans for retirement.

OBJECTIVE: This study examined an assumption of retirement theory that typifies older workers as preretirees who are planfully engaged in paths toward retirement. METHODS: Using survey responses among workers in the 1992 and 1994 waves of the Health and Retirement Study, we described the prevalence of nonsubstantive answers to questions about the expected form and timing of retirement (e.g., "don't know," "haven't thought about it"). We tested explanations for this uncertainty as an artifact of the survey process, but also as an outcome of the opportunity structure for retirement planning. RESULTS: Survey procedure did generate some of these noncommittal responses. Depending on question type, approximately 10% to 40% of workers did not state when or how they would retire, and such responses were less prevalent across age and time. In addition, categorical uncertainty about form and timing was theoretically predictable in a framework that supposed that workers less subject to a socially attended life--at work or away--would be more undecided about the future. DISCUSSION: Uncertainty is an authentic, meaningful stance toward retirement that theory and research design should not ignore. Just as actual transitions to retirement can be ambiguous or blurred, the expectation of retirement, as well, can be untidy.

Age Factors↗
PubMed1999

A feasibility study of gene gun mediated immunotherapy for renal cell carcinoma.

PURPOSE: Gene modified autologous tumor cell vaccines have demonstrated a protective and therapeutic effect in murine tumor model systems. The majority of trials to date have used viral methods of gene transfer for vaccine construction. An alternative approach to transfer genes into tumor cells is to use the gene gun, which is a physical method of gene transfection that produces high levels of gene expression without viral agents. We establish the feasibility of generating cytokine secreting autologous renal tumor cell vaccines for use in gene therapy for metastatic renal cell carcinoma. MATERIALS AND METHODS: We obtained 1 cm3 tumor tissue from 12 patients undergoing resection of primary or metastatic renal cell carcinoma. The tumor was disaggregated and placed in culture. The phenotype of the primary renal cell lines was established by microscopy and immunohistochemistry. The 1x10(7) lethally irradiated tumor cells were transfected with plasmid deoxyribonucleic acid containing the human (h) granulocyte-macrophage colony-stimulating factor (GM-CSF) gene under control of a cytomegalovirus promoter using the gene gun. The hGM-CSF production was assayed by enzyme-linked immunosorbent assay in the cell culture media 24 hours after transfection. RESULTS: Of 12 tumor samples 8 grew rapidly to produce a mean of 1.8x10(8) cells after 4 to 5 passages in culture, which was sufficient to produce between 24 and 32 vaccines. Immunocytochemistry confirmed that all cultures were almost exclusively renal tumor cells. Gene gun mediated transfection of lethally irradiated tumor cells resulted in high levels of hGM-CSF production (mean 330 ng./10(6) cells per 24 hours). CONCLUSIONS: We have demonstrated the feasibility of producing cytokine secreting tumor cell vaccines from primary and metastatic human renal tumors, and plan to use this approach in phase I clinical trials of gene therapy for metastatic renal cell carcinoma.

Biolistics↗
PubMed1998

STAT3 activation accompanies keratinocyte differentiation.

The signal transducers and activators of transcription (STAT) family of transcription factors has been demonstrated to play key roles in a variety of cell types under conditions that promote differentiation or cell cycle exit. We report our studies of primary murine keratinocytes in which we demonstrate activation of STAT3 during growth arrest and differentiation. In adherent cells, STAT3-specific DNA binding activity was detected in quiescent cultures, down-regulated upon mitogenic stimulation, and found to reaccumulate as cells reentered quiescence. Suspension culturing of proliferating keratinocytes, which induces differentiation, also resulted in induction of STAT3 activity. Furthermore, induction of STAT3 after suspension culturing did not occur in MK cells, an immortalized murine keratinocyte cell line that does not undergo differentiation. Because STAT3 activation in these cells corresponded tightly with the growth status, we examined whether there was a relationship between the cell cycle machinery and STAT3 activation by inhibiting p27kip1 accumulation, which is observed during growth arrest, with antisense oligonucleotides and by using keratinocytes lacking functional p27kip1. In both cases, there was a loss of STAT3 activation and a concomitant delay in terminal cell cycle withdrawal and in the expression of the differentiation specific marker, keratin 1. Thus, in addition to controlling transcription mediated through E2F, our data demonstrate that alterations in the cell cycle machinery are required for appropriate up-regulation of STAT3 activity that occurs during keratinocyte differentiation.

Animals↗
PubMed1993

Relationship between forward head posture and diagnosed internal derangement of the temporomandibular joint.

The purpose of this study was to determine if a sample of patients with internal derangement of the temporomandibular joint had a significantly greater amount of forward head posture than did an age- and gender-matched control group. Twenty-two patients at a single head, neck, and temporomandibular joint treatment center, who had the diagnosis of internal derangement of the temporomandibular joint, were compared with a control group of volunteers. The angle of each patient's head position was measured from four photographs (two of the patient sitting and two of the patient standing) with a diagonal line drawn from the spinous process of the seventh cervical vertebra to the tragus of the ear and a horizontal line drawn perpendicular to a plumb line suspended from the ceiling. The angles measured from each of the four photographs were averaged, and this figure was paired with that generated from an age- and gender-matched person in the control group. Results indicated that there was not a significantly greater degree of forward head posture in the experimental group.

Adolescent↗
PubMed1991

The aging population. A critical issue in medicine for the 21st century.

One critical issue facing medical science concerns the aging population. The number of individuals 65 years and older has increased during the past decade and likely will double by the year 2030, when the elderly will represent nearly 20% of the total population. This dramatic increase has numerous ramifications; health care is of utmost importance. Inherent in meeting the medical needs of these individuals is a fundamental understanding of the effects of aging on the functional integrity of numerous organ systems. In recognition of this problem, the Department of Pharmacology and Therapeutics at the University of South Florida College of Medicine has initiated a major effort focused on age-related research. The objectives are to elucidate fundamental biochemical, physiological, and pharmacological alterations that occur as a consequence of normal aging and to investigate the role of these perturbations on the manifestations of disease. Information gained from such studies will provide a rational approach in developing therapeutic strategies for the treatment of diseases affecting older citizens. This article presents a brief overview of four areas of research currently being pursued. These include aging and brain function, age-related alterations in drug metabolism, aging and smooth muscle function, and the effects of aging on the immune system.

Aging↗