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Biomedical subjects

L Burgess

Publications and source records attributed to L Burgess.

36 records · Page 2Linked to original sources
PubMed1987

Influence of the tissue distribution of ThioTEPA and its metabolite, TEPA, on the response of murine colon tumours.

Disposition studies in the same animals as those used for assessment of antitumor and toxic effects could increase understanding of the variation in response to cytotoxic drugs. Tissue and plasma levels of ThioTEPA and triethylenephosphoramide (TEPA) were measured to see if any correlation existed between them and the effects of the drug on a series of mouse colon tumours (MAC). The tumour panel included an ascitic form (MAC 15A), an anaplastic (MAC 13) and a well-differentiated (MAC 26) solid tumour, all grown subcutaneously. The maximum tolerated dose of ThioTEPA was 20 mg kg-1 in females bearing MAC 13 and 15 mg kg-1 in males having MAC 15A or 26. The diverse growth characteristics of the tumour cell lines necessitated the use of different methods for assessment of response. After administration of the maximum tolerated dose, the greatest response was observed in MAC 26, in which a growth delay of 15 days-twice the doubling time of the tumour volume-occurred. ThioTEPA produced 58% inhibition of MAC 13 tumour weight, but MAC 15A was unresponsive. One hour after intraperitoneal administration of Thio-TEPA (20 mg kg-1), ratios of tissue to plasma concentration were 1.13, 0.87 and 1.17 in tumours and 0.80, 0.75 and 0.73 in spleens of mice bearing MAC 13, 15A and 26 respectively. These data show greater accumulation of drug in neoplastic than in normal tissues. The pattern of distribution of the metabolite was similar, but there was a lesser degree of tissue accumulation than by the drug. Concentrations of drug and metabolite in neoplastic tissues related to their protein content were 116.0, 126.3 and 183.3 micrograms ThioTEPA/g and 57.5, 83.1 and 78.6 micrograms TEPA/g in MAC 13, 15A and 26 respectively. Combination of these chemosensitivity and pharmacokinetic data indicates that differences in response of these tumours to ThioTEPA cannot be explained by the availability of the drug and metabolite. The therapeutic effects of ThioTEPA cannot be predicted purely from a knowledge of drug and metabolite disposition.

Adenocarcinoma↗
PubMed1987

Quantitative analysis of myofibrillar protein subunits: demonstration of large molar excesses of myosin light chains in rabbit ventricular myocardium.

We describe a method for the complete solubilization and quantitative analysis of individual myofibrillar proteins in whole tissue homogenates of ventricular myocardium using gradient dodecyl sulfate polyacrylamide gel electrophoresis and staining with 125I-labeled Coomassie brilliant blue. The procedure allows for the simultaneous quantification of myosin heavy chain, myosin light chain, phosphorylatable myosin light chain and actin from as little as 50 mg of tissue. Within-assay and between-assay variations range from 8.0% to 12.6% for each protein subunit. The method was applied to the determination of the subunit stoichiometry of purified myosin, and to the measurement of myosin and actin concentrations in the neonatal and adult rabbit heart. Furthermore, we provide quantitative biochemical evidence for the existence of large molar excesses of myosin light chains in tissue homogenates of both neonatal and adult rabbit ventricular myocardium.

Actins↗
PubMed1987

Radiation damage repair capacity of a human germ-cell tumour cell line: inhibition by 3-aminobenzamide.

The capacity of a human germ-cell tumour line to repair radiation damage has been investigated by means of a clonogenic assay. Dose-rate dependence studies, split-dose experiments and experiments designed to measure repair of potentially lethal damage have been performed. The cells showed some ability to repair radiation-induced damage in all three types of experiment. An attempt has been made to understand the possible cellular mechanisms of these repair processes by the use of 3-aminobenzamide (3-AB), an agent thought to act by inhibition of ADP-ribosylation. 3-AB added 2 h prior to and removed 18 h after irradiation at a non-toxic dose to unirradiated cells caused a small but consistent increase in cell kill with acute (150 cGy min-1) irradiation, largely involving a reduction in the shoulder region of the survival curve, but had a greater effect in increasing cell kill at a dose rate of 7.6 cGy min-1 and an even greater effect at a dose rate of 1.6 cGy min-1. When 3-Ab was present 2 h prior to the first dose and between two equal doses in a split-dose experiment, inhibition of split-dose recovery was observed. In addition, some inhibition of potentially lethal damage recovery was observed with 3-AB. A possible role for poly(ADP-ribosylation) is thus implicated in the repair of radiation-induced damage of this human tumour cell line during continuous low dose rate or fractionated radiation schedules, although other effects of 3-AB on respiratory metabolism and/or purine synthesis cannot be eliminated as the cause of the observed inhibitory effects.

Benzamides↗
PubMed1987

Hospice in transition: Kentucky 1982-85.

The ratio of hospice patients to 100 Kentuckians dying of cancer was 8 in 1982 and 12 in 1985. The primary increase occurred in the number of patients served by three hospices which became Medicare-certified during that time period. During this period, the average age of hospice patients increased, and patients became more likely to die at home. Hospices in some counties may have served about 40 per cent of terminally ill cancer patients.

Age Factors↗
PubMed1984

Parotid tumors.

Explore the source record for details and available documents.

Adult↗
PubMed1982

Structural analysis of virion proteins of the avian coronavirus infectious bronchitis virus.

We have found six major polypeptides in virions of the avian coronavirus infectious bronchitis virus grown in tissue culture: four glycoproteins, GP84, GP36, GP31, and GP28, and two non-glycosylated proteins, P51 and P23. In addition, we detected three minor species: two glycoproteins, GP90 and GP59, and one non-glycosylated protein, P14. Two-dimensional tryptic peptide mapping showed that GP36, GP31, GP28, and P23 comprise a group of closely related proteins which we have designated the "P23 family," but that the other proteins are distinct. Analysis by partial proteolytic digestion of P23 family, but that the other proteins are distinct. Analysis by partial proteolytic digestion of the P23 family labeled biosynthetically with [35S] methionine, and P23, labeled with [35S] formyl-methionine by in vitro translation of RNA from infected cells, revealed that the proteins of the P23 family differ in their amino-terminal domains. Similar analysis of GP31 and Gp36 labeled with [3H] mannose showed that the partial proteolytic fragments unique to these proteins were glycosylated. This suggests that differences in glycosylation in the amino-terminal domains contributes to the marked polymorphism os the P23 family. The results are discussed with respect to possible models for synthesis of the virion proteins.

Coronaviridae↗
PubMed1981

Distribution of fibronectin during wound healing in vivo.

The distribution of fibronectin during wound healing has been studied. Full thickness wounds were made in the skin on the sides of guinea pigs' trunks. Biopsy specimens were taken from the normal skin, from the 5-hr-old wound, and on days 1-18 after wounding. Unfixed frozen sections were analyzed for fibronectin distribution by indirect immunofluorescence analysis with a specific antiserum prepared in rabbits against guinea pig plasma fibronectin. Tissue samples were also embedded in methacrylate and sections cut and stained with hematoxylin and eosin for general histology or with a silver stain for reticulin. Fibronectin was prominent in the basement membranes of normal skin epidermis. It was also present in the papillary dermis and to a lesser extent in the reticular dermis. After wounding, fibronectin was part of the fibrin clot and distributed along fibrin strands. Fibronectin was also deposited along newly synthesized collagen in the granulation tissue, which was at least in part collagen type III based upon staining for reticulin. Eventually, the entire granulation tissue was transformed into aligned collagen fibrils coated with fibronectin. Throughout the period of wound healing, the level of fibronectin associated with what appeared to be type I collagen in the reticular dermis adjacent to the wound area stayed about the same. When fibrils with the histological characteristics of type I collagen were within the granulation tissue, however, they were coated with fibronectin. The results indicate that fibronectin is a major component present during wound healing.

Animals↗
PubMedDate not supplied

Effects of hyaluronic acid/carboxymethylcellulose gel on bowel anastomoses in the New Zealand white rabbit.

Intra-abdominal adhesions form in more than 90% of patients undergoing major abdominal surgery and can lead to significant complications. Application of a bioresorbable gel consisting of chemically modified hyaluronic acid (HA) and carboxymethylcellulose (CMC) has shown promise as a means of preventing intra-abdominal adhesions, but there have been concerns that the presence of the gel might interfere with the integrity and healing of bowel anastomoses. We tested the effects of HA/CMC gel on adhesion formation and anastomotic healing in 60 New Zealand white rabbits after transection and complete (100%) or incomplete (90%) anastomosis of the ileum. Half of the animals underwent application of HA/CMC gel and half served as control subjects. Animals were killed at 4, 7, or 14 days after surgery. Anastomotic adhesions were scored in a blinded fashion. Integrity of the anastomosis was tested by measuring bursting pressure at the anastomotic site and in an adjacent section of intact bowel. With complete anastomosis, HA/CMC gel significantly reduced adhesion formation at 7 and 14 days after surgery (P<0.05), but gel application did not inhibit adhesion formation when the anastomosis was incomplete. Anastomosed segments of bowel burst at a lower pressure than intact bowel 4 days after surgery, but bursting pressures were normal at 7 and 14 days. Burst pressures of anastomoses receiving an application of HA/CMC gel were nearly identical to control anastomoses at all three time points. HA/CMC gel did not interfere with the normal healing process of bowel anastomoses. Furthermore, HA/CMC gel decreased adhesion formation after complete anastomoses, yet it did not affect adhesion formation in the presence of anastomotic disruption.

Anastomosis, Surgical↗
PubMedDate not supplied

Oncology focus. Facing the reality of head and neck cancer.

There are many facets and ideas surrounding the concept of body image, which are of particular importance to patients with defects of the head and neck who may have had to suffer extensive alterations to their appearance and bodily functions. This article discusses how nursing models can be used to help patients cope with their altered body image and the attitudes of society and the media to their disfigurement.

Adaptation, Psychological↗
PubMedDate not supplied

Twelve-lead electrocardiography in tuberculous pericarditis.

OBJECTIVES: This study is part of an ongoing initiative started in 1995 to investigate the therapeutic efficacy of adjuvant corticosteroids in the management of tuberculosis (TB) pericarditis. In this retrospective, descriptive study we describe the changes found on the 12-lead electrocardiogram (ECG) in patients with TB pericarditis, with and without cardiac tamponade. We determined the diagnostic accuracy of ECG parameters for cardiac tamponade. METHODS: All patients referred to our department with echocardiographically confirmed large pericardial effusions underwent a thorough clinical assessment followed by pericardiocentesis and drainage using an indwelling pigtail catheter. The amount of drained effusion was measured, and fluid was sent for diagnostic assessment. Patients were grouped into those with or without cardiac tamponade. The following ECG parameters were assessed: rate, rhythm, microvoltage, electrical alternans, PR segment and ST segment abnormalities. RESULTS: Of the 157 patients assessed, 88 were diagnosed with TB pericarditis All had abnormal ECGs and 83% had changes of chronic pericarditis. Microvoltage in the extremity and/or precordial leads correlated with the presence of large effusions (> 750 ml). None of the studied parameters correlated with the presence of cardiac tamponade. CONCLUSIONS: Twelve-lead ECG is of supportive but not diagnostic value in cardiac tamponade. The presence of microvoltage suggests the presence of a large effusion. The absence of microvoltage makes the presence of cardiac tamponade unlikely.

Cardiac Tamponade↗
PubMedDate not supplied

Mixed-sex wards--the NT survey results.

The practice of rigidly separating men and women in hospital has broken down in recent years; the RCN estimates that half of all acute hospital wards are now mixed. In January, NT invited readers to give their opinions on mixing males and females in the same wards and to describe their own areas of work. Chief areas of concern that emerged were: patients not being informed about the ward being mixed before admission; lack of privacy (especially in bathroom and lavatory areas); and in patients' unhappiness with the proximity of patients of the opposite sex. Although complaints were common, most were informal. Further research, preferably from a 'neutral' source, is needed.

Female↗