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Biomedical subjects

A Roldan

Publications and source records attributed to A Roldan.

11 recordsLinked to original sources

Catecholamine levels in practitioners of the transcendental meditation technique.

With the aim of evaluating the sympathetic-adrenal medulla system in subjects practicing transcendental meditation (TM), their plasma catecholamine levels were determined at two different times of day. The study group consisted of 19 subjects who regularly practice either TM or Sidhi-TM technique, with a control group made up of 16 healthy subjects who had not previously used any relaxation technique. Catecholamine plasma levels were determined by high performance liquid chromatography, at 0900 and 2000 h. Morning and evening norepinephrine (NE) levels and morning epinephrine (E) levels were significantly lower in the TM group than in the control subjects (morning NE levels, pg/ml, mean+/-S.E.: TM group 136.6+/-13.0, control 236.8+/-21.0, P=.0001; evening NE levels: TM group 119.7+/-10.8, control 175.6+/-17.4, P=.009; morning E levels, pg/ml: TM group 140.2+/-10.6, control 196.7+/-23.8, P=.019). No differences were recorded for evening E levels and dopamine (DA) levels. No significant differences were found for catecholamine levels measured at different times of day in the TM group, demonstrating a lack of daily hormonal rhythm. Anxiety levels were similar in both groups. Based on the results obtained, it can be considered that the regular practice of TM has a significant effect on the sympathetic-adrenal medulla system. A low hormonal response to daily stress caused by sympathetic tone regulation through regular TM could explain our results, as well as the physiological and other effects related to the field of health described in those who practice meditation.

Adolescent↗

ACTH and beta-endorphin in transcendental meditation.

We have evaluated the effect of Transcendental Meditation (TM) on the hypothalamo-hypophyseal-adrenal axis diurnal rhythms through the determination of hormone levels. Blood samples were taken at 0900 hours. and at 2000 hours. These samples were taken from 18 healthy volunteers who regularly practice TM and from nine healthy non-meditators. Cortisol, beta-endorphin, and adrenocorticotropic hormone (ACTH) were measured at both hours. TM practitioners showed no diurnal rhythm for ACTH and for beta-endorphin (ACTH, pg/mL, mean +/- SE; 13.8+/-1.2 - 12.1+/-1.5/beta-endorphin, pg/mL; 14.4+/-1.5 - 17.2+/-1.9, at 0900 hours and 2000 hours, respectively), in contrast to control subjects, who showed normal diurnal rhythm for these hormones and for cortisol (ACTH, pg/mL; 19.4+/-1.9 - 11.9+/-2.2/beta-endorphin, pg/mL; 25.4+/-1.7 - 17.7+/-1.1/Cortisol, ng/mL; 201.4+/-13.2 - 71.3+/-6.5, at 0900-2000 hours, respectively, p < 0.01 in the three cases). Practitioners of TM with similar anxiety levels to those of the control group showed a different pattern in the daytime secretion of pituitary hormones. TM thus appears to have a significant effect on the neuroendocrine axis. Because cortisol levels had a normal pattern in the TM group, these results may be due to a change in feedback sensitivity caused by this mental technique.

Adrenocorticotropic Hormone↗

2'-Chlorodeoxyadenosine: evaluation of a novel predominantly lymphocyte selective agent in lymphoid malignancies.

2'-Chlorodeoxyadenosine (2CDA) is a purine analogue selectively active against both resting and dividing lymphoid cells. Twenty-one patients with a variety of previously treated lymphoid malignancies received a total of 41 courses of 2CDA (0.1-0.15 mg/kg/day over 7 days continuous intravenous infusion) on compassionate grounds. The profile of the patient population was as follows: low grade non-Hodgkin's lymphoma (NHL) = 8, intermediate grade NHL = 2, transformed (intermediate grade NHL) = 6, Hodgkin's disease = 1, lymphoplasmacytoid NHL = 3 and lymphoblastic NHL = 1. The overall response rate was 53%, with three patients attaining complete remission (CR) and eight partial remission (PR). Three of 16 patients with primary resistant or resistant recurrent disease entered either CR (1) or PR (2). Ten patients had no response or progressive disease. The latter group was comprised of patients who had extensively pre-treated lymphoplasmacytoid tumours and/or poor performance status (WHO grades 2-4). The median duration of response is 6 months (range 1 to 12 months). Treatment was well tolerated and the chief toxicities were leucopenia and thrombocytopenia which were most pronounced when there was bone marrow involvement. As a result of dose limiting myelotoxicity, a dose escalation to 0.15 mg/kg/day was possible on just three occasions. These data confirm other reports of the activity of 2CDA in low grade NHL and indicate it may have activity in Hodgkin's disease. There was no demonstrable activity in poor performance status patients or those with extensively pre-treated lymphoplasmacytoid tumours.

Adult↗

EPIC: an effective low toxicity regimen for relapsing lymphoma.

We have treated 40 patients was relapsed or resistant lymphoma with the combination of Etoposide, Prednisolone, Ifosfamide and Cisplatin (EPIC). Complete response was obtained in 11 patients (28%) with an overall response of 58%. The presence of bulky disease (P < 0.005), elevated LDH serum levels (P < 0.005), response to prior chemotherapy (P < 0.01) and B symptoms (P < 0.005) were significantly associated with response. However on multivariate analysis only the presence of bulky disease and of B symptoms were independent adverse factors for response and for survival. The regimen was well tolerated with myelosuppression being the most common toxicity. Leucopenia < or 1,000 microliters-1 and thrombocytopenia < or = 25,000 microliters-1 developed in 27% and 4% of cycles respectively. There were no treatment related deaths. The EPIC regimen has equivalent activity to other reported cisplatin based regimens used in the treatment of recurrent lymphoma, but is associated with lower treatment related morbidity and mortality.

Adult↗

Role of magnetic resonance imaging in predicting relapse in residual masses after treatment of lymphoma.

PURPOSE: This prospective study of patients treated at the Royal Marsden Hospital Lymphoma Unit was designed to evaluate the role of magnetic resonance imaging (MRI) in the assessment of residual masses evident on computed tomographic (CT) scanning following treatment of lymphoma. PATIENTS AND METHODS: All patients had MRI, gallium-67 single-photon emission CT (67Ga SPECT), and erythrocyte sedimentation rate (ESR) performed within 3 months of completing therapy. Patients were monitored for 1 year posttreatment and observed for signs of relapse. Investigation results were correlated with disease status, and the sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV) calculated. Time-to-relapse curves were derived and the log-rank test used to determine whether patients with a positive result were more likely to have a relapse within the mass than those with a negative result. RESULTS: Thirty-four patients were studied, 14 of whom relapsed, 11 within the area of residual mass. Overall, MRI had a high specificity (90%), PPV (71%), and NPV (75%), but poor sensitivity (45%). The results for 67Ga SPECT were similar, apart from lower sensitivity (33%). ESR had inferior performance in predicting relapse compared with the other tests. MRI was the only investigation to show statistical significance (P = .14) in predicting relapse, and this was particularly evident in Hodgkin's lymphoma (P = .003). Combining results of 67Ga SPECT and MRI did not improve predictive power. CONCLUSION: These data demonstrate that MRI is a valuable tool in the setting of a residual mass after treatment, giving clinically useful prognostic information. 67Ga SPECT also has a role, but is less effective in predicting relapse than MRI.

Actuarial Analysis↗

Insulin-like growth factor-1 increases the mitogenic response of human peripheral blood lymphocytes to phytohemagglutinin.

Receptors for insulin and insulin-like growth factor-1 (IGF-1) have been demonstrated on activated T-lymphocytes. The question is whether receptors for insulin or IGF-1 have any function in these cells. In this study we demonstrate that the concentration of IGF-1 in commercial samples of fetal calf serum is about 70 times that of insulin. Moreover, antibodies binding IGF-1 reduce responses of human peripheral blood mononuclear cells to PHA by about 50%, whereas antibodies to insulin have no demonstrable effect. These observations suggest that binding of IGF-1 to specific receptors contributes to the proliferative responses of activated T-lymphocytes.

Animals↗