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Biomedical subjects

G Mead

Publications and source records attributed to G Mead.

9 recordsLinked to original sources

Direct and indirect measures of memory for modality in young and older adults.

In 2 experiments, young and older adults demonstrated modality effects of similar magnitude in perceptual identification tasks. That is, both young and older adults demonstrated more repetition priming when study and test modalities matched than when they were different, suggesting that contextual information was equally available across age. However, when asked explicitly to retrieve modality information, older adults were less accurate than young adults. These results constitute evidence for a dissociation between direct and indirect measures of memory for modality information. They call into question hypotheses that memory impairment in old age is due to deficient encoding of contextual information and challenge current accounts of modality effects in repetition priming.

Acoustic Stimulation

BOP/VIP--a new platinum-intensive chemotherapy regimen for poor prognosis germ cell tumours.

Ninety-one patients with poor prognosis non-seminomatous germ cell tumours (NSGCT) were treated with an initial intensive chemotherapy schedule. Suitable patients fulfilled one or more of the following criteria: lymph node metastases greater than 10 cm diameter; liver, brain or bone metastases; serum HCG level greater than 50,000 IU/L; and extragonadal primary tumours. Treatment consisted of 3 cycles of bleomycin, vincristine and cisplatin (BOP) administered at 10 day intervals, followed by 3 cycles of etoposide, ifosfamide and cisplatin (VIP) at 21 day intervals. A total of 64 patients (70%) achieved a complete remission. This comprised 46 patients who received BOP/VIP only, and 18 patients who received additional chemotherapy after BOP/VIP. Of these 64 patients, 51 underwent complete surgical resection of residual masses, including 11 in whom there was evidence of teratoma with cellular atypia or non-germ cell cancer in the resected tissue. A further 9 patients had persisting unresected radiological masses in the presence of marker complete remission. The overall response rate was 80%. Currently 57 patients (63%) remain alive and free from disease progression. The median follow-up period is 90 weeks (range 24-206 weeks), with a 2 yr actuarial progression-free survival of 66% (95% c.i. 55-77%). Major toxicity was myelosuppression, occurring during the VIP arm of therapy, with a median nadir WBC of 1.1 x 10(9)/L and median platelet count of 51 x 10(9)/L. Other toxicity included peripheral neuropathy (WHO Grade 2 and 3 in 22%). We conclude that treatment results with the BOP/VIP schedule in this poor prognosis patient group are at least comparable with other schedules, and toxicity is manageable.(ABSTRACT TRUNCATED AT 250 WORDS)

Antineoplastic Combined Chemotherapy Protocols

Electroconvulsive therapy in octogenarians.

Medical records of 81 older patients (65 years of age and over) who underwent electroconvulsive therapy (ECT) at a university-affiliated private geriatric hospital were reviewed to evaluate the safety and efficacy of this treatment for depression in the "young-old" (65 to 80 years) compared with the "old-old" age group (over 80 years), a group that has not yet been adequately studied. Information was obtained regarding demographics, medical and psychiatric diagnosis, medications, indications for ECT, number and laterality of treatments, outcome, and complications. Thirty-nine patients 80+ years of age (mean age, 85 +/- 3.2) were compared with 42 patients 65 to 80 years of age (mean age, 74 +/- 5.2). Statistical analysis was performed using confidence intervals of the difference in proportions of patients in each group. There were no significant differences in the demographics, number and laterality of ECT treatments, indications for ECT treatment, medical diagnosis, medications, or prior history of falls, but psychiatric diagnoses differed slightly. Patients over 80 years had significantly more cardiovascular complications and falls (95% confidence interval) and tended to have a worse ASA (American Society of Anesthesiologists) scale rating and a somewhat less successful outcome. This study confirms the role of ECT as a relatively safe and effective treatment, which may be lifesaving in selected depressed older patients. Prospective studies are needed to understand better the long-term outcome and to prevent the morbidity and mortality associated with ECT in this frail, high-risk older group.

Accidental Falls

Surgery after initial chemotherapy for localized small-cell carcinoma of the lung.

Despite the high response rates induced by chemotherapy, many patients with limited small-cell lung cancer (SCLC) relapse at the site of primary disease. Failure of radiotherapy to overcome this has led to the use of surgery as part of a combined modality approach. Between December 1981 and December 1985, 189 patients with SCLC were assessed for suitability for surgery after an initial three cycles of chemotherapy (doxorubicin, cyclophosphamide, and etoposide). Fifty-seven were found to have limited disease, and of these, 19 were ineligible or unfit for surgery. Of the 38 eligible patients, 84% had an objective response to three cycles of chemotherapy and 25 were deemed suitable for surgery after restaging. At thoracotomy, four were inoperable, nine had a lobectomy, and 12 had a pneumonectomy. There was no evidence of viable SCLC in four resection specimens (one stage 1, two stage 2, one stage 3 at presentation), no viable SCLC but an entirely separate focus of viable poorly differentiated squamous carcinoma (SqLC) in one, and the remaining specimens contained viable SCLC. Survival of patients selected to undergo tumor resection was excellent (median survival, 33 months; plateau phase, 48% alive at 3 to 5 years), but survival of the entire group with limited SCLC was not dissimilar from that reported in previous series of limited-stage tumor treated with chemotherapy alone. Long-term survival appeared to be largely restricted to those with no evidence of viable SCLC at surgery (no viable SCLC, zero of five relapsed; viable SCLC, 13 of 16 relapsed and/or died). This prospective study confirms the feasibility of the combined modality approach, but suggests that any improvement in overall survival is likely to be small. Until the results from multicenter randomized trials are available, surgery, as part of a combined modality program, should be regarded as experimental.

Actuarial Analysis

Myocardial infarction with and without laboratory documentation--one year prognosis.

This retrospective study indicates that patients admitted to our CCU with a history typical for myocardial infarction appear to have a comparable in-hospital mortality rate after 48 hours, a comparable one-year mortality rate, and a comparable incidence of recurrent myocardial infarction during the first year, whether or not they develop confirmatory ECG or serum enzyme changes. Patients with chest pain typical of myocardial infarction, who fail to develop confirmatory ECG or serum enzyme changes, would appear to require the same care and follow-up as do those patients admitted with chest pain who do develop such ECG or serum enzyme changes.

Clinical Enzyme Tests

Competitive exclusion in the young bird: challenge models, administration and reciprocal protection.

The competitive exclusion (CE) concept has been tested against both non-invasive and invasive salmonella serotypes. Studies with different challenge models indicate that CE treatment is likely to protect the young bird against all serotypes that are capable of intestinal colonization. Spray or 'droplet' application of the CE-treatment material was compared with administration in the first drinking water. Both methods gave a similar degree of protection against Salmonella infantis. A study was made to compare protection of newly hatched chicks and turkey poults by the one commercial CE product Broilact, and two similar preparations involving intestinal microorganisms from an adult turkey. Each preparation protected both avian species when administered orally prior to challenge, but the degree of protection obtained varied with the type of preparation and its host origin.

Animals