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Biomedical subjects

R Miller

Publications and source records attributed to R Miller.

At least 685 records · Page 38Linked to original sources
PubMed1985

Effects of intensive clinical exposure on attitudes of medical students toward cancer-related problems.

The attitudes of third-year medical students toward cancer and patients with cancer was examined before and after a 6-week clerkship that included contact with pediatric patients with cancer and their families. A 51-item testing instrument was employed, which included pediatric, adult, and general oncology questions. Beginning with positive attitudes toward the importance of early diagnosis, aggressive therapy, and the complete disclosure of prognosis, the clinical exposure appeared to strengthen the two former attitudes and somewhat diminish the latter. Approval of aggressive cancer therapy was stronger for children than for adults; but approval of both aggressive therapy and intensive surveillance of patients in remission was increased in regard to adults as well as children after the clerkship. A comparison with responses of second-year medical students from another institution suggests that third-year students recognize greater personal limitations in respect to management and adopt a more "defensive" position regarding the patient. In general, during the clerkship, the students moved in the direction of attitudes that were previously designated to be appropriate for students by a multidisciplinary committee that was distinct from the instructional staff in oncology.

Adult↗
PubMed1985

Medical students' concepts of childhood cancer and its management.

Medical student's attitudes toward cancer and patients with cancer were studied prior to and following a required pediatric clerkship which included contact with children on an oncology service. Emphasis in the study was placed on the students' reactions to the child with cancer, and these were compared with the same students' attitudes in the context of the adult with cancer or general oncology. Early diagnosis is regarded as of more significance, and an aggressive therapeutic response following diagnosis of more urgency when the patient is a child. These attitudes, recognizing the importance of early diagnosis and expressing strong approval of aggressive therapy for the pediatric patient, increased during the clerkship. The students strongly supported a program aimed at return of the child to his normal activities with the least delay; recognized the special significance of long-range surveillance for secondary effects in the pediatric patient; and recommended the "center" as opposed to the community hospital as the site for care of the child with cancer. In other areas of cancer management, including (a) the importance of psychosocial support, (b) the problems of emotional involvement of the physician with the patient, and (c) care of the dying patient, attitudes toward patients in the two age groups was not significantly different.

Attitude of Health Personnel↗
PubMed1985

Analysis of heterogeneity in daunorubicin uptake by human leukemia cells using laser flow cytometry.

Heterogeneity in daunorubicin uptake by leukemic blast cells obtained from the bone marrow of 16 patients with acute leukemia (10 acute nonlymphocytic leukemia and 6 acute lymphocytic leukemia) was determined by laser flow cytometry following drug treatment in vitro for 1 hr. Fluorescence profiles of cellular anthracycline levels in the various samples indicated a marked heterogeneity in daunorubicin uptake and the range of detectable drug fluorescent cells was 34%-99%. A retrospective analysis of disease outcome in these patients who were treated with a daunorubicin or doxorubicin containing induction regimen indicated the following: (a) 8 of 11 patients who entered complete remission had greater than 80% of leukemic blast cells accumulating detectable amounts of daunorubicin; and (b) 3 of 4 patients who did not respond to chemotherapy had less than 40% of the leukemic blast cells accumulating detectable amounts of daunorubicin. These results suggest that laser flow cytometry may be useful in determining qualitative and quantitative differences in daunorubicin levels in heterogeneous tumor cell populations.

Adolescent↗
PubMed1985

Tolerance of peripheral nerve to intraoperative radiotherapy (IORT): clinical and experimental studies.

In our clinical experience combining wide excision and intraoperative radiotherapy (IORT), five patients have developed clinical signs of lumbosacral or sciatic neuropathy within 9 months of receiving IORT to a dose of 20-25 Gy. Three patients showed recovery of nerve function over several months while two patients have shown no recovery and have near complete loss of extremity function. In an attempt to investigate this clinical observation further, the lumbosacral plexus and sciatic nerve of American foxhounds were surgically exposed and received a single dose of IORT ranging from 20-75 Gy. An approximate linear relationship between radiation dose and time to onset of hind limb paresis is found with 19 of 21 irradiated dogs showing clinical signs of nerve injury within an interval of 1-19 months. No recovery of nerve function is seen in these dogs. Histological study of the irradiated nerves demonstrates a loss of nerve fibers, particularly those of the large myelinated type without evidence of vascular occlusion or thrombosis. These studies suggest that peripheral nerve may be a dose-limiting normal tissue in clinical studies of IORT.

Adult↗
PubMed1985

A comparison of triazolam and diazepam as premedication agents for minor gynaecological surgery.

Triazolam 0.25 mg, diazepam 10 mg and placebo were compared in a randomized double-blind trial of oral premedication in 90 patients undergoing minor gynaecological surgery. Both triazolam and diazepam produced a significant sedative effect as measured by patient self assessment linear analogue scales but only diazepam was more anxiolytic than placebo. Psychomotor performance assessed by the letter-search test at 3 and 6 hours after awakening showed a decrement in performance in patients receiving triazolam at 3 hours compared with the two other groups. Triazolam was shown to have a pronounced amnesic effect and whilst it might be used for premedication, its lack of anxiolysis coupled with a significant impairment of psychomotor performance at 3 hours after awakening, render the drug unsuitable for premedication in the short stay patient.

Adult↗
PubMed1985

Lymphocyte subpopulations in allergic granulomatosis and angiitis (Churg-Strauss syndrome).

We report a case of allergic granulomatosis and angiitis (Churg-Strauss syndrome) in which immunologic parameters, including lymphocyte subpopulations, were determined in the acute phase of the disease and during remission. Hyperimmunoglobulinemia E and immune complexes were present. A low proportion of suppressor/cytotoxic (T8+) lymphocytes and a high helper/suppressor ratio were seen throughout the course of the disease, although immunoglobulin levels and circulating immune complex levels decreased with therapy. We hypothesize that the deficiency of suppressor cells may play a role in the pathogenesis of this syndrome.

Aged↗
PubMed1985

LAV/HTLV III presence in peripheral blood lymphocytes of seropositive young hemophiliacs.

Recent studies indicate a high prevalence of seropositivity to the lymphadenopathy-associated virus/human T-lymphotropic virus (type III) among individuals with hemophilia exposed to clotting factor concentrates prepared from large donor pools. The peripheral blood lymphocytes of 19 young seropositive patients with inherited bleeding disorders were examined for the presence of this virus by coculture with phytohemagglutinin-stimulated lymphocytes. Viral isolates were obtained from six of 19 patients. While none of these patients have developed the acquired immunodeficiency syndrome (AIDS) or AIDS-related complex, five of them had lymphadenopathy in two noncontiguous areas, and two showed clinically symptomatic enlarged tonsils and adenoids. Of the 13 patients in whom virus was not demonstrated, five were judged clinically normal and five had mild lymphadenopathy in one anatomical area. These results suggest that as many as 33% of hemophiliacs (six of 19 patients studied), who have circulating antibodies to mature viral proteins, have viral-infected peripheral blood lymphocytes capable of infecting other lymphocytes in vitro.

Adolescent↗
PubMed1985

The effect of a 550 nm cutoff filter on the vision of cataract patients.

The effect on visual function of an optical filter which absorbs essentially all visible wavelengths below 550 nm has been studied in a group of patients with moderate stage cataracts. Using a Snellen-type visual acuity chart with a blue background and orange letters, under both glare and non-glare conditions, the visual acuity of these patients was determined. Improvement in acuity was more striking under glare conditions than under standard (non-glare) conditions; in the former case it reached levels as high as 300% in a few patients. The level of the improvement seemed to be related both to cataract type and stage of cataract progression.

Cataract↗
PubMed1985

Pathology of gastrointestinal tract in chronic hemodialysis patients: an autopsy study of 78 cases.

The pathological data obtained from postmortem examination of the gastrointestinal tract in 78 chronic hemodialysis patients are reported. All but two of the patients exhibited some gastrointestinal abnormalities. Multiple abnormalities often coexisted in one individual. Esophagitis, gastritis, duodenitis, enteritis, and colitis were seen with considerable frequency. However, extensive hemorrhagic, ulcerative, and pseudomembranous lesions frequently seen in untreated uremia were generally lacking. Evidence of peptic ulcer disease was found in one-fourth of the patients confirming the increased predisposition of dialysis patients to this complication. Several patients exhibited various ischemic phenomena including thrombosis, embolism, and infarction of various segments of the gastrointestinal tract. In addition, numerous other abnormalities were found throughout the gastrointestinal tract with lesser frequency. The data indicate that various gastrointestinal abnormalities commonly occur in patients with endstage renal disease despite uremia control by hemodialysis. However, the observed abnormalities are different from those reported in untreated uremia.

Adult↗
PubMed1985

Effects of tabernanthine on calcium and catecholamine stimulated contractions of isolated vascular and cardiac muscle.

The Iboga alkaloid tabernanthine (80 microM) non-competitively antagonized contractions in both the rat aorta and mesenteric artery induced by cumulative additions of noradrenaline and calcium. Tabernanthine (8, 40 and 80 microM) antagonized the K+ depolarization-induced contractions of the aorta. Tabernanthine (80 microM) depressed the phasic component of contractions induced by a single maximal concentration (10 microM) of noradrenaline in Ca++ -free solution. Tabernanthine induced a negative inotropic effect in electrically stimulated myocardial tissue and a negative chronotropic effect in the perfused rat heart. Tabernanthine is a calcium entry blocker which also affects cellular calcium metabolism.

Alkaloids↗
PubMed1984

Neurons in the ventral tegmentum have separate populations projecting to telencephalon and inferior olive, are histochemically different, and may receive direct visual input.

The connections of the ventral tegmental area (VTA) and medial terminal nucleus (MTN) of the accessory optic system were studied in the albino rat. Using injection of two fluorescent retrograde tracers it was found that individual neurons of the VTA project to frontal cortices or the inferior olive but not both structures. Using combined retrograde fluorescent tracers and glyoxylic acid histochemistry, it was found that although a third of the cells projecting to frontal cortex contained catecholamine, none of the cells projecting to the inferior olive contained catecholamine. Thus, these portions of the ascending and descending VTA systems are independent. In addition, using injections of the anterograde transneuronal tracer [3H]adenosine into one eye, it was found that cells in the VTA, as well as the MTN, contained the tracer. Therefore, there is a basis for direct retino-mesentelencephalic pathways through the VTA.

Animals↗
PubMed1984

Absorption properties of two theophylline sustained-release products in smokers.

The absorption of theophylline from two commercial products labelled as having sustained-release properties (Theo-dur; Rio-Ethicals; and Euphyllin Retard; Byk-Gulden) was compared with that of a solution of theophylline (Alcophyllin syrup; Propan-Lipworth) in a multiple-dose study in smokers. As regards bioavailability, results for Theo-dur and Euphyllin Retard tables were statistically indistinguishable from that for the standard, but both products showed significantly slower absorption as reflected by longer times to attain peak concentration and lower peak concentrations. Theo-dur exhibits better sustained-release properties than Euphyllin Retard as judged from the peak/trough ratio and the persistence of concentrations from 6 hours to 12 hours after administration. Assuming linear pharmacokinetics and projecting to therapeutic doses, Euphyllin Retard results in much wider fluctuations between peak and trough concentrations (18,9 and 9,8 micrograms/ml) than does Theo-dur (13,8 and 10,2 micrograms/ml), and this product might be more acceptable in smokers if given in an 8-hourly schedule.

Absorption↗