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Biomedical subjects

J Lancaster

Publications and source records attributed to J Lancaster.

At least 19 recordsLinked to original sources
PubMed1991

Regulation of Agrobacterium tumefaciens T-cyt gene expression in leaves of transgenic potato (Solanum tuberosum L. cv. Désirée) is strongly influenced by plant culture conditions.

The promoter region of the Agrobacterium tumefaciens T-cyt gene was linked in a translational fusion to the coding DNA of the reporter gene uidA (for beta-glucuronidase or GUS protein; EC 3.2.1.31) and to nos 3' flanking DNA. The chimaeric gene was introduced by Agrobacterium transformation into potato (Solanum tuberosum L. cv. Désirée). In nine transgenic lines, the average GUS levels were highest in extracts from stems and roots of in vitro grown plants (ca. 11,000 GUS activity units per pmol MU per mg protein per min) but lower in leaves of the in vitro grown plants (ca. 7000 units). GUS activity was intermediate in stems and roots of plants grown in soil as well as in in vitro crown galls (ca. 3000 units). Activity was low in tubers, irrespective of whether these developed in vitro or in soil (both ca. 100 units), and lowest of all in leaves of soil-grown plants (ca. 10-15 units). However, in shoot cultures reestablished from soil-grown plants, GUS activity in the leaves increased to that determined in the original shoot cultures. Hence, plant culture conditions strongly influenced the expression of the T-cyt-uidA-nos gene. In particular, it was silenced in leaves of soil-grown plants. The results are compared with previous analyses of the promoter region of the wild-type T-cyt gene and with the growth properties of a large number of crown gall cell lines and crown-gall-derived plants, including over forty S. tuberosum cv. Désirée cell lines isolated in the present study that were transformed with the wild-type T-cyt gene and six promoter-mutated derivatives. A number of implications are discussed for crown gall formation and for control of expression of plant genes which contain Activator or G-box type 5' expression control sequences.

Agrobacterium tumefaciens↗
PubMed1990

Effect of cyclic estrone sulfate treatment on lipid profiles of postmenopausal women with elevated cholesterol levels.

The effects of two doses of cyclic unopposed estrone sulfate therapy on the lipid profiles of 153 healthy postmenopausal women with baseline total cholesterol levels above 219 mg/dL were compared in a multicenter, double-blind, placebo-controlled study. Patients were assigned randomly to one of three treatment groups: estrone sulfate 0.625 mg (N = 59) or 1.25 mg (N = 43), or placebo (N = 51). The median baseline total cholesterol levels of the three treatment groups were 262, 269, and 262 mg/dL, respectively. Total cholesterol, triglycerides, high-density lipoprotein cholesterol (HDL), low-density lipoprotein cholesterol (LDL), and the HDL/LDL ratio were assessed after 6, 9, and 12 months of treatment. There was a significant monotonic dose-response relationship of estrone sulfate in raising HDL levels, lowering LDL levels, and raising the HDL/LDL ratio at all intervals measured. These results indicate that estrone sulfate is effective in creating a beneficial change in the lipid profile of postmenopausal women with elevated baseline total cholesterol.

Cholesterol, HDL↗
PubMed1989

About radiotherapy--Part II. Side effects and staff protection.

Special side effects which relate to specific areas are discussed. Head and neck radiation produces acute problems related to swallowing, dry mouth, sore throat and thickened saliva which all require medication. Alteration of taste may last for months after radiation is completed. Radiation to lungs may cause worsening breathlessness and coughing which may necessitate interruption of treatment. Radiation to pelvis and abdomen result in nausea and diarrhoea which usually respond to treatment. Proctitis, vaginal discharge and urinary problems all need attention. With cranial radiation, hair loss is a major problem and unlike chemotherapy induced alopecia, there is poor recovery. Patients must be informed that their condition will improve when radiation ceases, and not attribute all symptoms to underlying disease. Protection in this country is in line with international standards and strict adherence protects the work force. Patients with radioactive sources in situ e.g. radium or implants such as gold seeds, iridium wires, or being treated by radioactive iodine all require special nursing and are nursed in a protected ward. Staff wear film badges to detect radiation absorbed. If in doubt about safety measures contact superiors or radiophysics department of hospital. Patients already isolated from visitors must not be neglected and nurses must observe instructions and then proceed with safety.

Abdomen↗
PubMed1988

Human breast tumor imaging using 111In labeled monoclonal antibody: athymic mouse model.

The monoclonal antibody (MoAb) 323/A3, an IgG1, was raised against the human breast tumor cell line MCF-7 and recognized a 43 Kd membrane associated glycoprotein. Histochemical studies with the antibody detected 75% of metastatic lymph nodes, 59% of primary breast tumors, and showed some staining in 20% of benign breast lesions. For radionuclide imaging, the MoAb 323/A3 was labeled with both 125I and 111In, via covalently coupled diethylenetriaminepentaacetic acid (DTPA) by the mixed anhydride method. The antibody activity of the DTPA modified 323/A3 was assessed by an immunoassay using viable and fixed MCF-7 target cells. Male athymic nude mice bearing BT-20 human mammary tumors were injected with dual 125I/111In labeled DTPA 323/A3 via the tail veins. The animals were imaged with a gamma camera equipped with a pinhole collimator at 1-3 h, 1, 2, 3, 4 and 5 days after the tracer administration. On day 5 or 6, the animals were killed, and the biodistribution of the radiotracers was determined for the blood, thyroid, heart, lungs, liver, spleen, kidneys, gastrointestinal tract and tumor. Target to blood ratio at 6 days for the 111In tracer was 24:1 in the group with a mean tumor weight of 0.492 g, and 13:1 in another group with a mean tumor weight of 0.1906 g (day 5). However, the 125I activity showed only 3.6:1 and 5.4:1 target to blood ratios in the corresponding groups. The larger tumors localized less 111In tracer (27.13% +/- 7.57% injected dose/g, Mean +/- SD) than the smaller tumors (52.75% +/- 22.25% ID/g).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

Hemodynamically important right ventricular infarction: follow-up evaluation of right ventricular systolic function at rest and during exercise with radionuclide ventriculography and respiratory gas exchange.

The prognosis and recovery of right ventricular systolic function in patients with hemodynamically documented right ventricular myocardial infarction (RVMI) is unclear. Therefore 27 patients who met hemodynamic criteria for RVMI were followed for at least 1 year. Four patients died within 1 year and 23 survived. Postmortem examination performed in three of the four patients showed extensive infarction of the right and left ventricles. Survivors underwent early and late follow-up resting radionuclide ventriculograms and late exercise studies. During long-term follow-up (1 to 4 years) resting radionuclide ventriculography demonstrated a significant improvement in right ventricular ejection fraction (30 +/- 7% to 43 +/- 8%; p less than .001) and right ventricular wall motion index (2.2 +/- 0.4 to 1.5 +/- 0.5; p less than .001) in 18 patients who survived longer than 1 year. Fourteen of these patients underwent upright bicycle exercise while off beta-blocking drugs and peak radionuclide ejection fraction was acquired after anaerobic threshold was achieved. Right ventricular ejection fraction increased significantly from 41 +/- 10% to 47 +/- 12% (p less than .001), as did the left ventricular ejection fraction (55 +/- 15% to 60 +/- 12%; p less than .05). The direction and magnitude of change of the right ventricular ejection fraction correlated significantly with the left ventricular ejection fraction (r = .82, p less than .02). Deviations from this correlation occurred in patients who had a decreased forced expiratory volume in 1 sec and an abnormal ventilatory reserve during exercise.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1986

1986 and beyond. Nursing's future.

Predicting the future is a risky effort for nursing administrators. What we can do is reevaluate our past and learn how the lessons of prior eras can help us understand the trends affecting health care and nursing and plan strategies for moving nursing forward. Specifically, to move forward we must effectively deal with our image, mechanism for educating students, attainment of public accountability and professional autonomy, political skills, and becoming more actively involved in research to document the value of nursing.

Aged↗