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Biomedical subjects

D Gibson

Publications and source records attributed to D Gibson.

At least 55 records · Page 3Linked to original sources
PubMed1996

Time course from first symptom to treatment in patients with non-small cell lung cancer referred for radiotherapy: a report by the CHART Steering Committee.

BACKGROUND: Only a small proportion of patients with non-small cell lung cancer (NSCLC) attending radiotherapy centres were suitable for inclusion in a randomised trial which compared continuous hyperfractionated accelerated radiotherapy (CHART) with conventional radical radiotherapy. As this was thought to be partly due to delays in the referral of patients to clinical oncologists, a prospective study was performed to determine the interval between first report of symptoms and first radiotherapy treatment in patients with NSCLC. METHODS: The time course from first symptom to treatment was determined in all patients with NSCLC attending 10 cancer centres for radiotherapy to a primary tumour in a three month period. RESULTS: Only 5% of 484 patients were suitable for the trial of radical radiotherapy. The principal causes for exclusion were poor general condition (37%), too large a tumour (27%), and extrathoracic metastases (19%). The median time from first symptom to diagnosis was 13 weeks, from first symptom to first treatment 19 weeks, and from diagnosis to first treatment five weeks. In a quarter of the patients these intervals were greater than 25,33 weeks, and nine weeks, respectively. CONCLUSION: The reason for these long intervals needs investigation since earlier diagnosis and more immediate referral for consideration of treatment might increase the number of patients with NSCLC suitable for radical radiotherapy.

Aged↗
PubMed1995

Preparation, characterization, and antitumor properties of cis-PtCl2 complexes linked to anthraquinones through position number 2.

A new series of platinum-anthraquinone complexes of the type cis-PtLL'Cl2 [where L is the monodentate AQ-NH-(CH2)n-NH2 and L' = NH3 or LL' is the bidentate ligand AQ-NH-(CH2)n. NH-(CH2)2-NH2] in which the anthraquinone is linked to the diaminedichloroplatinum (II) moiety through position 2 was prepared and screened in vitro for antileukemic activity against P388 cells. All ligands were characterized by 1H and 13C NMR spectroscopy and all complexes by 195Pt NMR. The platinum complexes of anthraquinones which are modified in position 2 are significantly less potent than their analogs which are substituted in position 1. The activity of the complexes is either equal to or lower than the activity of the free ligands themselves. In the attempt to prepare AQ-NH-(CH2)4-NH-(CH2)2-NH2, a new compound, 2-(N-pyrrolidine)anthraquinone, was obtained and its structure was determined by x-ray crystallography. It crystallized in the monoclinic system in the space group P2(1)/c. The unit cell parameters are a = 9.595(1), b = 12.537(2), c = 11.461(1) A, beta = 94.14(2) degrees, V = 1375(1) A3, and z = 4.

Animals↗
PubMed1995

Definition and application of a fourier domain texture measure: applications to histological image segmentation.

A texture measure is defined for the purpose of two-dimensional histological image classification, based upon a novel exploitation of the modulus of the Fourier transform. Its implementation in the form of an algorithm is presented and discussed, and employed to classify a set of histological images. The results, which were obtained by the analysis and classification of different mammalian tissue types, compare favourably with established texture recognition techniques. Furthermore, the results suggest that the method has a comparable performance to other techniques at reduced storage and time costs for images of a high grey level resolution.

Algorithms↗
PubMed1995

The changing availability of residential aged care in Australia.

Australian aged care services have undergone a series of substantial reforms in recent years under the rubric of the Aged Care Reform Strategy. Overall, there has been a progressive refinement of the targeting of available services on those most in need, defined in terms of both disability levels and financial resources. A key component of this process has been a deliberate reduction in the relative emphasis accorded to nursing home care within the aged care system. This has been accompanied by increases in the resources directed toward less intensive forms of residential care (hostels) and community based services. This paper explores the actual consequences of these intentional policy changes in terms of the availability of nursing home and hostel care, and the changing characteristics of nursing home residents. The results suggest that a more substantial reduction has occurred in the availability of nursing home care than has hitherto been suggested, with consequent decreases in the proportion of aged persons in nursing homes. The effect has been particularly marked amongst women and the very old. These findings raise policy questions about the appropriateness of current and planned future levels of provision.

Aged↗
PubMed1995

UKCCCR Register of U.K. Cancer Trials.

The UKCCCR Register of U.K. Cancer Trials comprises an on-line database of all randomized trials of cancer therapy, whether phase III or randomized phase II trials. Both current or open trials, and closed or completed trials, are included. Abstracts of any publications associated with the trials are also included. The UKCCCR Register is the initial component of a larger European register of trials. This article describes the structure and content of the database, the PC program for data entry, and the Unix-based browsing software for interactive access over networks. Problems of ensuring complete and comprehensive registration of trials, and sources of information, are also reviewed.

Clinical Trials, Phase II as Topic↗
PubMed1995

User rights and the frail aged.

There is a growing acceptance of user rights models with regard to dependent populations such as nursing home residents, but classic theories of rights presuppose levels of human rationality and human agency often lacking in the case of highly dependent populations. While user rights models have strong advantages at a rhetorical level, the reduced capacity for dependent groups to assert their rights constitutes a significant limitation. Policies, practices and regulatory strategies developed on the assumption that very dependent groups can indeed assert such rights thus proceed on a premise which is fatally flawed.

Aged↗
PubMed1994

Platinum(II) triamine complexes: cis-[PtCl(NH3)2(C10H13N5O5)]NO3.2H2O and [PtCl(C2H8N2)(C4H6N2)]NO3.

The structures of cis-diamminechloro(guanosine-N7)-platinum(II) nitrate dihydrate, cis-[PtCl(NH3)2-(C10H13N5O5)]NO3.2H2O, (I), and chloro(ethylenediamine)(1-methylimidazole-N3)platinum(II) nitrate, [PT-(C2H8N2)(C4H6N2)Cl]NO3, [PtCl(en)(1-MeIm)]NO3, (II), were determined by single-crystal X-ray diffraction. The former complex crystallized in the orthorhombic system and the latter in the monoclinic system. In compound (I), water molecules were found to connect the metal complex with the nitrate counter ions via hydrogen bonding.

Crystallography, X-Ray↗
PubMed1994

Is double data entry necessary? The CHART trials. CHART Steering Committee. Continuous, Hyperfractionated, Accelerated Radiotherapy.

There is some controversy over the need for double data entry in clinical trials. In particular, does the number and types of errors identified with this approach justify the extra effort involved? We report the results of a study carried out to address this question. Our main outcome measure was the frequency and types of errors involved in the entry of data for the CHART (continuous, hyperfractionated, accelerated radiotherapy) trials. Data were reentered for a sample of 44 patients by a data manager other than the one making the initial entry. The second entry was then compared with the first entry. The error rate for the two entries combined was 14 per 10,000 data items (fields) (95% confidence interval 10, 19). The error rate for the initial entry alone was 15 per 10,000 fields (95% confidence interval 9.5, 22), and the vital/important error rate (defined as any error on a principal outcome measure or a major error on any other endpoint or variable) was 2.5 per 10,000 fields (95% confidence interval 0.68, 6.4). On this evidence double data entry is not performed for the CHART trials.

Carcinoma, Non-Small-Cell Lung↗
PubMed1994

Time for clients: temporal aspects of community psychiatric nursing.

Time is an integral element in all actions, organizations and relationships. Temporality has an effect on people's lives, and in turn people manipulate temporality as a means of imposing social order. From a semiotic perspective the amount of time spent on an action and the timing of its conveys messages about such things as importance and status. This holds equally true of organizations as well as individuals. This paper concentrates on a community psychiatric nursing department, its staff and clients. Sections of speech taken from interviews with nurses and clients are presented and discussed from the perspective of temporality to show how relationships are managed on an individual level and how work is organized around different client groups at an organizational level.

Attitude of Health Personnel↗
PubMed1994

Measurement of membrane phospholipid asymmetry in normal and sickle-cell erythrocytes by means of annexin V binding.

We investigated the use of annexin V (placental anticoagulant protein I), a calcium-dependent protein that binds tightly to phosphatidylserine-containing membranes, as a means to measure membrane phospholipid asymmetry in human erythrocytes. Iodine 125-labeled annexin V bound to erythrocytes in a specific, reversible, calcium-dependent reaction (dissociation constant = 25 +/- 4 nmol/L at 37 degrees C and 2.5 mmol/L calcium). Lysed erythrocytes contained 1.2 x 10(6) binding sites for annexin V. Treatment of erythrocytes with 1 mumol/L A23187 in the presence of 2.5 mmol/L calcium at 37 degrees C caused a gradual but marked increase in annexin V binding sites, reaching a level of approximately 300,000 sites per cell after 8 hours of incubation. We also noted a very gradual spontaneous exposure of annexin V binding sites during storage of purified erythrocytes, reaching a level of approximately 20,000 sites per cell after 30 days. Measurements could also be made directly on diluted whole blood specimens. In samples freshly drawn from 35 normal donors, a mean number of 276 sites per cell were present; this increased to 858 sites per cell after storage of specimens at 4 degrees C for 24 hours. Measurement of annexin V binding to samples from patients with sickle-cell anemia revealed a marked increase in binding (mean of 12,430 sites per cell for all samples); serial measurements in a patient hospitalized with sickle-cell crisis showed a progressive decline in annexin V binding over a period of 6 days.(ABSTRACT TRUNCATED AT 250 WORDS)

Annexin A5↗