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Biomedical subjects

J M Ford

Publications and source records attributed to J M Ford.

At least 127 records · Page 7Linked to original sources
PubMed1982

Analgesics and cancer of the renal pelvis in New South Wales.

A lifetime history of analgesics and tobacco consumption was obtained by a questionnaire completed at interview from 67 patients with carcinoma of the renal pelvis (40 women, 27 men) and 180 control subjects drawn from two sources, friends of patients and persons attending a health screening clinic. Regular consumption of analgesics conferred a tenfold relative risk of renal pelvic cancer in women and in men a risk ratio of 4-8. The fraction of cases for which analgesic consumption was an attributable risk was 0.74 in women and 0.43 in men. The effect of tobacco, much less than that of analgesics, was significant only in women (risk ratio approximately four; attributable risk 0.4), and no dose-response relationship was demonstrated. Relative excess risks suggested a synergistic effect when both analgesics and tobacco had been consumed. Standardized risk ratios indicated a dose-response relationship for both phenacetin-containing and non-phenacetin analgesics: moderate consumption doubled the risk of renal pelvic cancer, and heavy consumption increased at risk to 6-16 times that for noncomsumers.

Age Factors↗
PubMed1982

Short-term treatment for acute myelogenous leukaemia.

Short-term treatment with doxorubicin, cytarabine, and 6-thioguanine was given to 91 consecutive adults with acute myelogenous leukaemia. Fifty patients received high doses (regimen I) and 41 very high doses (regimen II). Where possible, six treatment cycles were given (total dose of doxorubicin 450 mg/m2) regardless of the number of cycles required to achieve complete remission. No additional treatment was given. The remission rate was significantly higher with regimen I than with regimen II (34/50 compared with 15/41, p less than 0.01), the latter, more intensive regimen being associated with a greater incidence of fatal infection (13/41 compared with 5/50, p less than 0.01). Duration of remission was, however, significantly longer with regimen II (p less than 0.05); the median has not yet been reached after a minimum follow-up of two years. Intensive short-term treatment is a feasible strategy for the treatment of acute myelogenous leukaemia.

Adolescent↗
PubMed1982

A new combined assay of phagocytosis and intracellular killing of Escherichia coli by polymorphonuclear leukocytes.

A new combined radiometric assay is described in which adherence, and phagocytosis and killing of Escherichia coli by human polymorphonuclear leucocytes (PMN) are simultaneously measured in the same sample. Pure monolayers of PMN in Petri dishes are allowed to ingest [14C]phenylalanine labelled E. coli and excess bacteria are removed by washing. A period of incubation allows intracellular killing to occur while polymyxin-B is added to half the dishes to kill extracellular bacteria. The remaining viable bacteria in all dishes are labelled with [3H]thymidine. The number of ingested bacteria and the percentage of intracellular organisms killed is determined from the 14C and 3H counts by a simple subtraction technique. By performing protein assays on representative monolayers, the number of PMN adhered in the monolayers and hence the mean bacterial uptake per PMN is estimated. The assay detected killing efficiencies reduced below the normal range, in monolayers treated with sodium azide, phenylbutazone, in polymorphonuclear leukocytes from patients with chronic granulomatous disease, and in immature neutrophils from the promyelocytic leukaemic cell line, HL60. The assay was adapted to measure phagocytosis and killing by cells in suspension.

Azides↗
PubMed1982

Effects of perceptual and cognitive difficulty on P3 and RT in young and old adults.

Ten healthy old and 10 healthy young subjects each received a series of trials in a memory retrieval task similar to that devised by Sternberg (1967). On each trial the subject saw a memory set of 2 or 4 digits (set size) followed by a probe. The task was to indicate whether the probe was a positive or negative instance (response type) of the memory set for that trial. On half the trials, the probe digits were degraded by a mask of random dots (stimulus quality). For both young and old subjects, RT was later to probes following the larger set size, later to degraded probes, and later to negative probes. For the young subjects only, P3 latency was delayed by the same variables affecting RT although to a lesser degree. P3 latency in the elderly responded quite differently: it was unaffected by set size or response type. However, P3 was somewhat delayed by the degraded probes suggesting that the failure to reflect set size or ceiling effect in the elderly. The correlation between single-trial P3 latency and RT in the elderly is lower than in the young. The data are discussed in terms of age-related differences in the meaning of P3 latency.

Adult↗
PubMed1982

Expectancy for events in old age: stimulus sequence effects on P300 and reaction time.

Event-related brain potentials were collected from 10 young (M = 22 years) and 10 elderly (M = 77 years) women. Stimuli were random sequences of 1000- and 1500-Hz tone pips in a two alternative, forced choice, reaction time task. Trials were sorted and averaged according to the sequence of the preceding four tones: continuations of repetitions (AAAAA) and alternations (ABABA) and discontinuations of repetitions (BBBBA) and alternations (BABAA). For both groups the P300 component of the event-related brain elicited larger P300s than did discontinuations of alternations, an effect especially large for the elderly women. Mean reaction time did not differ between the two groups, although P300 latencies were significantly longer for the elderly group. Results are discussed in terms of age-related differences in response strategies and sensitivity of P300 latency to response strategy.

Acoustic Stimulation↗
PubMed1981

A cross-matching procedure for the selection of platelet donors for alloimmunized patients.

A platelet cross-matching procedure has been assessed for selecting compatible donors for alloimmunized patients. This confirms the clinical value of combining an indirect platelet immunofluorescence test (PIFT) with a lymphocytotoxicity test (LCT) in predicting the survival of single-donor platelets. There was good agreement between the PIFT cross-match and post-transfusion platelet recovery. Compatibility in the LCT alone was insufficient for platelet donor selection, as this test did not detect all antibodies affecting platelet survival. Positive LCT and PIFT cross-matches indicated the presence of HLA antibodies. Inclusion of an indirect lymphocyte immunofluorescence test (LIFT) helped to classify the platelet antibody when the LCT cross-match was negative. In such cases, parallel positive findings with the LIFT and PIFT suggested a cytotoxic-negative antibody of probable HLA specificity active against platelets. Disparity between the LIFT and PIFT was also observed; a strongly positive PIFT along with a weak reaction in the LIFT suggested that a platelet-specific antibody was responsible for the poor platelet survival in these cases. This study has also shown the presence in multitransfused patients of LIFT-positive antibodies not reacting in the LCT and PIFT, which do not affect the survival of transfused platelets. A positive granulocyte cross-match was demonstrated in patients with febrile rigors associated with compatible platelet transfusions. Splenectomy and steroids may improve the survival of incompatible platelets depending on the nature of the platelet antibody.

Adult↗
PubMed1980

Chemotherapy and immunotherapy for acute myelogenous leukemia.

Eighty-six consecutive untreated adults with acute myelogenous leukemia were treated with a combination of Adriamycin, vincristine, prednisolone, Cytosine Arabinoside, and BCG. Complete remission was achieved in 39 (45%) patients; these patients were then allocated on an alternate basis to receive BCG and monthly chemotherapy with or without weekly irradiated allogeneic blast cells. The median duration of remission was eight months and was the same for both groups. The median survival of those achieving complete remission was 19 months compared with two months for those not achieving complete remission. Nine patients are still alive without relapse and five of these patients have been disease free for more than three years.

Adolescent↗
PubMed1980

Age differences in P3-reaction time associations.

Eight healthy old and 12 healthy young women had event-related potentials (ERPs) recorded during the performance of a memory retrieval task. For each subject the single trial data recorded at Pz were analyzed using Woody's adaptive filter technique. The old subjects differed from the young in several respects: P3 amplitude at Pz was smaller, P3 latency and reaction time (RT) were greater, the relationship between P3 latency and RT was considerably altered. The adaptive filter increased the amplitude of P3 but the age-related amplitude difference persisted, suggesting that this difference is not due to increased latency variability with age. The old subjects had lower single trial P3-RT correlations and longer elapsed time from P3 peak to the response than did the young subjects. Both groups had greater RTs for outset items ('negative' responses) than for inset items ('positive' responses). For the young subjects P3 latency was also greater for the outset compared to the inset items but the difference was not found for the old subjects. Thus, the relationship between P3 latency and RT is altered in the aged--P3 and RT are less tightly coupled than in the young.

Adult↗
PubMed1980

Age-related changes in auditory event-related potentials.

Twelve elderly and 12 young women were subjects in a reaction-time task designed to elicit middle and late event-related potentials (ERP). The aged subjects differed from the young in respect to the later occurring ERP components: P2 was larger and later; P3 was later and had a different scalp distribution; the slow wave (SW) was smaller. In contrast, no age-related differences were found for N1 amplitude or latency. It is suggested that the diminution in SW amplitude contributes to the change in scalp distribution of P3 amplitude seen with age. The relationship of reaction time and P3 latency of single trials was examined by the adaptive filter technique. There was no difference between the old and young subjects as both groups revealed signficant, positive P3 latency-reaction time correlations.

Adult↗