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Biomedical subjects

D Glencross

Publications and source records attributed to D Glencross.

11 recordsLinked to original sources
PubMed1999

Microvolume fluorimetry for the determination of absolute CD4 and CD8 lymphocyte counts in patients with HIV: a comparative evaluation.

This study compared CD4 and CD8 lymphocyte counts obtained by microvolume fluorimetry (MVF) with those derived by flow cytometry (FC). Samples from 192 patients with known or suspected HIV were analysed, and the distribution of CD4 counts for these samples ranged from 0 and 1,279/microl, with 142/192 (74%) of the samples having CD4 values of less than 400/microl. Good agreement between FC and MVF CD4 counts was found (MVF = 0.98 x FC + 7.30) although there was a minor constant inter-method bias of approximately +7 cells/microl for the MVF data. For CD8 counts there was a constant bias between the two methods of approximately +23 cells/microl for FC. Most outliers were associated with higher FC CD8 counts. Supplementary analyses showed a high level of agreement between FC and MVF methods for the CD4:CD8 ratios (MVF = 0.98 x FC). This suggests that observed discrepancies between FC and MVF methods were almost certainly a result of the influence of the absolute lymphocyte counts obtained from the haematology analyser. The results confirm that the IMAGN 2000 microvolume fluorimeter system can be used as an alternative to conventional flow cytometry for the enumeration of CD4 and CD8 counts.

CD4 Lymphocyte Count↗
PubMed1995

The effects of alcohol on preparation for expected and unexpected events.

The present paper is concerned with investigating the effects of alcohol in situations where unexpected events occur and responses need to be cancelled and reprogrammed. One experiment is reported which involved the modification of an eight-choice reaction-time task, employing the priming procedures of Posner to investigate the effects of alcohol on decision times to expected and unexpected events. The experiment involved a series of valid pre-cues in which accurate information was provided about the up-coming response, and a series of invalid pre-cues in which the "wrong" information was given to subjects. The effects of alcohol (0.09% BAC) was significant on the invalid trials, in which reaction time slowed significantly and error rates increased significantly. The results are discussed in terms of response processing and attention-switching.

Journal Article↗
PubMed1991

Quantification and assessment of viability of Pneumocystis carinii organisms by flow cytometry.

Analysis of drug efficacy in animal models of Pneumocystis carinii pneumonia requires an accurate method of quantification of organisms, as well as a means of assessing viability. Lung homogenates were prepared from a colony of athymic nude F344 rats experiencing a spontaneous outbreak of P. carinii pneumonia. With the fluorescent nucleic acid stain propidium iodide, flow cytometric analysis was able to quantify P. carinii cysts and trophozoites reproducibly. As this stain is excluded by living cells, this method was also used to assess the viability of organisms. Application of this technique to analysis of bronchoalveolar lavage specimens was demonstrated.

Animals↗
PubMed1989

A field study report of intensive computer keyboard training with schoolchildren.

A video-based keyboard skills training programme was used to teach primary and secondary school students to touch type, in ten 45-min lessons. Previous research (Glencross and Bluhm, 1986) had found the programme to be successful in training a variety of personnel in the workforce. In all, 197 students (105 females, 92 males) received instruction over a two-week period. The influence of age (11-12, 13-14, 15-16, 17-18 years) and sex on keyboard operating speed and accuracy were examined. Speed tests were conducted after the second and ninth lesson. Significant improvements in speed of typing were recorded for all age categories. Age and sex were found to be associated with speed of typing and rate of improvement across tests. Error rates remained constant across tests.

Journal Article↗
PubMed1986

Intensive computer keyboard training programmes.

An intensive computer keyboard training course, based on an information processing model of man, was tested on a variety of personnel in work. Over a one or two week period, 241 adult subjects were trained. Subjects achieved mean speeds of 7.1 words per minute (WPM) after the second and 13.7 WPM after the ninth lesson. Significant decreases in errors per minute (EPM) occurred from 2.67 to 1.78. Previous experience with a keyboard and being female were factors associated with enhanced keyboard operating performance. Compressing the ten lessons from two into one week reduced the effectiveness of the programme.

Journal Article↗
PubMed1983

Programming precision in repetitive tapping.

The present paper reports an experiment using the Fitts' tapping paradigm. It is concerned with a comparison of movement times and accuracy during blind and visual repetitive tapping. A blind condition was used to investigate rapid aiming movements under motor program control, whilst visual aiming was used to assess the role of visual feedback for control purposes. Subjects in the blind conditions were able to replicate the amplitude specifications of the task, whereas effective target width was constant for a set amplitude and did not reflect specified target width. Subjects, furthermore, responded more rapidly when tapping blind. These results are discussed in terms of the magnitude of forces being attempted as a result of performing a set amplitude, and the role of visual feedback.

Journal Article↗
PubMedDate not supplied

Non-cryopreserved, limited number (1 or 2) peripheral blood progenitor cell (PBPC) collections following GCSF administration provide adequate hematologic support for high dose chemotherapy.

Sixty-two patients with a variety of malignant diseases including 44 with breast cancer, seven with sarcomas, five with germ cell tumours, four with Hodgkin's disease and two with multiple myeloma received short duration, high dose chemotherapy, with non-cryporeserved peripheral blood progenitor cell rescue as treatment for malignancy. Limited, (one or two) peripheral blood precursor cell collections were performed following either cyclophosphamide, cyclophosphamide+GCSF or GCSF priming. Total nucleated cell and CD34+ cell yields were significantly higher with either of the two GCSF priming regimens as compared to cyclophosphamide only priming. Cell viability at the time or reinfusion was also enhanced by GCSF priming. Chemotherapy regimens included either high dose cyclophosphamide, mitoxantrone and VP16 (HD-CNV); high dose melphelan plus VP16; high dose BCNU, cyclophosphamide and VP16 (BCV); or high carboplatin, cyclophosphamide and VP16 (PCV) all given over 8-12 h. Non-cryopreserved blood progenitor cells, stored at 4 degrees C, were reinfused 24 h after completion of chemotherapy. Sixty-one of 62 patients showed hematologic recovery. Median time to hematologic recovery was significantly shorter for patients receiving GCSF primed cell collections. There was also significantly less hospitalization and antibiotic usage for patients receiving GCSF primed precursor cell collections. The addition of post chemotherapy GCSF did not, however, appear to enhance the rate of hematologic recovery. This study shows that simplified schedules for high dose chemotherapy administration together with simple precursor cell collection procedures provide safe and effective methods for administering myeloablative chemotherapy treatment.

Antineoplastic Combined Chemotherapy Protocols↗