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Biomedical subjects

A Ballard

Publications and source records attributed to A Ballard.

14 recordsLinked to original sources
PubMed2001

Leptin enhances the calcification of vascular cells: artery wall as a target of leptin.

Leptin, the product of the ob gene, regulates food intake, energy expenditure, and other physiological functions of the peripheral tissues. Leptin receptors have been identified in the hypothalamus and in extrahypothalamic tissues. Increased circulating leptin levels have been correlated with cardiovascular disease, obesity, aging, infection with bacterial lipopolysaccharide, and high-fat diets. All these conditions have also been correlated with increased vascular calcification, a hallmark of atherosclerotic and age-related vascular disease. In addition, the differentiation of marrow osteoprogenitor cells is regulated by leptin. Thus, we hypothesized that leptin may regulate the calcification of vascular cells. In this report, we tested the effects of leptin on a previously characterized subpopulation of vascular cells that undergo osteoblastic differentiation and calcification in vitro. When treated with leptin, these calcifying vascular cells had a significant 5- to 10-fold increase in alkaline phosphatase activity, a marker of osteogenic differentiation of osteoblastic cells. Prolonged treatment with leptin enhanced the calcification of these cells, further supporting the pro-osteogenic differentiation effects of leptin. Furthermore, the presence of the leptin receptor on calcifying vascular cells was demonstrated using reverse transcriptase polymerase chain reaction, immunocytochemistry, and Western blot analysis. We also identified the presence of leptin receptor in the mouse artery wall, localized to subpopulations of medial and adventitial cells, and the expression of leptin by artery wall cells and atherosclerotic lesions in mice. Taken together, these results suggest that leptin regulates the osteoblastic differentiation and calcification of vascular cells and that the artery wall may be an important peripheral tissue target of leptin action.

Alkaline Phosphatase↗
PubMed2001

Adenovirus-mediated overexpression of dominant-negative mutant of c-Jun prevents intercellular adhesion molecule-1 induction by LDL: a critical role for activator protein-1 in endothelial activation.

Low density lipoprotein (LDL) induces intercellular adhesion molecule-1 (ICAM-1) gene expression and leads to endothelial cell (EC) leukocyte adhesion. However, the transcriptional mechanism for LDL-induced EC perturbation remains to be fully explained. Activator protein-1 (AP-1) is induced after the exposure of ECs to LDL. In the present study, a regulated adenovirus expressing a dominant-negative mutant of c-Jun (TAM-67) was used to examine the role of AP-1 in the LDL-induced ICAM-1 activation. Overexpression of TAM-67 specifically inhibited AP-1 activation and prevented the LDL-activated surface expression of ICAM-1 protein in human umbilical vein ECs and human coronary artery ECs. Northern analyses and promoter transactivation assays indicated that this effect of TAM-67 was likely mediated through a suppression of the transcriptional regulation of the ICAM-1 gene. Functionally, TAM-67 attenuated leukocyte adherence to ECs in response to LDL. Furthermore, electrophoresis mobility shift assays and site-directed mutagenesis suggested that an AP-1-like motif in the promoter region of the human ICAM-1 gene was a critical cis element for LDL induction. These results, for the first time, provide evidence suggesting that AP-1 is a major regulatory mechanism leading to endothelial activation.

Adenoviridae↗
PubMed1997

A comparison of the level of hope in patients with newly diagnosed and recurrent cancer.

PURPOSE/OBJECTIVES: To compare levels of hope in patients with newly diagnosed and recurrent cancer. DESIGN: Descriptive study. SETTING: Three oncology practices in two urban areas of the southern United States. SAMPLE: Convenience sample of 20 newly diagnosed patients with cancer and 16 patients with recurrent cancer (mean age = 56 years). The majority of the patients were Caucasian, female, and married; had a high school degree; and had a religious affiliation. METHODS: Subjects completed the Herth Hope Scale and answered the open-ended question "What gives you the most hope at the present time?" Analysis included descriptive statistics (i.e., frequency, means, standard deviations, percents), t-tests, Chi-square, and analysis of variance. MAIN RESEARCH VARIABLES: Level of hope each subject had in relation to the stage of the cancer at the time of diagnosis. FINDINGS: Contrary to expectations, patients with newly diagnosed and recurrent cancer did not differ in regard to their level of hope. However, significant differences were found related to the type of hope utilized. Married patients and male patients experienced higher levels of hope. Recurrent themes in response to the open-ended question were family support, nonfamily support, faith, outlook, and health professionals/care. CONCLUSIONS: Patients with newly diagnosed cancer use their treatment and nurses, physicians, and other healthcare professionals as sources of hope and support. Patients with recurrent cancer reported drawing hope from faith. IMPLICATIONS AND NURSING PRACTICE: Heightened awareness of the patient-healthcare professional relationship will enable healthcare professionals to provide care that is more sensitive to one congruent with patients' needs. Healthcare professionals need to assess the meaning of faith for each individual patient and offer services to foster this source of hope.

Female↗
PubMed1993

Genomic concatemerization/deletion in rotaviruses: a new mechanism for generating rapid genetic change of potential epidemiological importance.

Three variants of group A rotavirus with large changes in their gene 5 structures have been analyzed at the molecular level. The first of these, P9 delta 5, was obtained during plaque purification undertaken as part of the biological cloning of a field isolate of virus. The gene 5 homolog in this isolate migrated just ahead of the normal segment 6 RNA, giving an estimated size of 1,300 bp. Molecular cloning and sequencing of this homolog revealed it to have a single 308-bp deletion in the center of the normal gene 5 sequence extending between nucleotides 460 and 768 of the normal gene sequence. This deletion caused a frameshift in the gene such that a stop codon was encountered 8 amino acids downstream of the deletion point, giving a predicted size for the protein product of this gene of 150 amino acids compared with the 490 amino acids of its normal-size counterpart. Attempts to detect this shortened protein in virus-infected cells were not successful, indicating that it was much less stable than the full-length protein and/or had suffered a large change in its antigenicity. The second two variants, brvA and brvE, were generated in an earlier study following the high-multiplicity passage of the UKtc strain of bovine rotavirus. Polyacrylamide gel electrophoresis analysis of these nondefective variants showed that brvA had a gene 5 homolog approximately equal in size to the normal RNA segment 2 (approximately 2,700 bp) and that brvE had a size of approximately 2,300 bp. Both variants showed changes in their gene 5 protein products, with brvA mimicking P9 delta 5 in failing to produce a detectable product whereas brvE produced a new virus-specific protein approximately 80 kDa in size. Full-length cDNA clones of the brvE gene 5 homolog were isolated, and analysis of their structure revealed a head-to-tail concatemerization of the normal gene 5 sequence with the first copy of the concatemer covering nucleotides 1 to 808 and the second covering nucleotides 92 to 1579, giving a total length of 2,296 bp. Sequencing across the junction region of the two copies of the gene showed that they were joined in frame to give a predicted combined open reading frame of 728 amino acids with the amino-terminal region consisting of amino acids 1 to 258 fused at the carboxy terminus to amino acids 21 to 490.(ABSTRACT TRUNCATED AT 400 WORDS)

Amino Acid Sequence↗
PubMed1992

Nucleotide sequences of normal and rearranged RNA segments 10 of human rotaviruses.

Normal and rearranged RNA segments 10 of group A rotaviruses isolated from a chronically infected immunodeficient child were amplified by the polymerase chain reaction as full-length cDNA copies, and were subsequently cloned and sequenced. Compared with the nucleotide sequence of the normal RNA segment 10, the rearranged form contains a partial non-coding duplication at its 3' end and several point mutations. The normal RNA segment 10 was similar to that of bovine rotavirus.

Amino Acid Sequence↗
PubMed1992

A serotype 10 human rotavirus.

Rotaviruses with genome rearrangements isolated from a chronically infected immunodeficient child (F. Hundley, M. McIntyre, B. Clark, G. Beards, D. Wood, I. Chrystie, and U. Desselberger, J. Virol 61:3365-3372, 1987) are the first recognized human isolates of serotype 10. This was shown by both a direct enzyme-linked immunosorbent assay and virus neutralization assays using serotype specific monoclonal antibodies. The serotype was confirmed by sequence analysis of the gene encoding VP7, which revealed a 96% amino acid homology to the bovine serotype 10 isolate B223.

Amino Acid Sequence↗
PubMed1988

Posterior cruciate ligament avulsion associated with ipsilateral femur fracture in a 10-year-old child.

Ligamentous injuries to the knee do occur in children with open physes. Rarely, the posterior cruciate ligament may be involved and prompt attention to repair when recognized is encouraged. While avulsion occurs, more commonly, from the femoral insertion of the posterior cruciate, the tibial origin may be the site of injury, as in this case report. Complete examination of fractured femurs in children is therefore necessary. Early ligamentous repair is superior to later reconstruction.

Bone Nails↗
PubMed1980

Plantar fascial spaces of the foot and a proposed surgical approach.

This study identified five plantar fascial spaces of the foot. The first space lies superficial to the calcaneus, the second lies between the plantar aponeurosis and the flexor digitorum brevis, the third lies between the flexor digitorum brevis and the quadratus plantar, the fourth lies above the quadratus, and the fifth lies above the adductor hallucis. A plantar incision is proposed for exploration and drainage of foot injuries and infections. With this incision, the plantar neurovascular bundles, along with the five plantar spaces through which infection spreads, are visualized clearly. In our experience, the incision heals without a sensitive scar.

Cadaver↗
PubMed1977

Prophylactic antibiotics in elective orthopedic surgery: a prospective study of 1,591 cases.

A double-blind prospective study involving 1,591 clean orthopedic surgical procedures was done to test the effectiveness of preoperative and intraoperative antibiotics in reducing the postoperative infection rate. The antibiotic and placebo groups were analyzed carefully for factors known to predispose to infection. Several minor exceptions were noted, but generally the antibiotic and placebo groups were comparable with regard to these factors. A decrease in overall postoperative infection rate from 5.0% in the placebo group to 2.8% in the antibiotic group was found. In specific areas such as the hip and spine a much greater reduction in postoperative wound infections occurred than in the group as a whole.

Adult↗
PubMed1975

The functional treatment of pyogenic arthritis of the adult knee.

A method of treatment of pyogenic arthritis of the adult knee employing wide open arthrotomy and early active motion, as well as synovectomy in some knees, was used in thirty-four patients with pyogenic arthritis of the knee. Of these patients, sixteen had a good result, twelve had a fair result, and six had a poor result. This method of treatment was used as a salvage procedure in most of the patients, but may have more general application in the treatment of pyogenic arthritis of the knee.

Ankylosis↗