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Biomedical subjects

A C Miller

Publications and source records attributed to A C Miller.

14 recordsLinked to original sources

Inhibition of glutathione reductase activity by a carbamoylating nitrosourea: effect on cellular radiosensitivity.

Nitrosoureas inactivate cellular glutathione reductase. N,'N'1,3-bis(trans-4-hydroxycyclohexyl)-N'-nitrosoureas (BCyNU), a nitrosourea reported to selectively inhibit glutathione reductase (GR) activity, was examined to determine if it could be used as a means to inhibit cellular levels of this enzyme in radiobiology studies. Confirmation of drug-induced inhibition of GR activity was demonstrated using a cell-free model system employing purified GR. Cellular studies with Chinese hamster V79A03 showed that BCyNU decreased cellular glutathione content concomitant with an inhibition of specific GR activity. Under relatively nontoxic conditions, cellular exposure to BCyNU (25 microM, 0.25 h) either before or after radiation treatment, increased cellular radiosensitivity with the optimum time for drug addition being immediately following radiation. At a BCyNU dosage which produced less than or equal to 5% cell toxicity, a marked decrease in radioresistance was characterized as a reduction in both Dq (24 +/- 1.5%) and Do (8 +/- 0.5%) concomitant with a 25 +/- 2% decrease in cellular glutathione reductase (GR) activity. At cytotoxic drug dosages (25 microM, 1 h; cell survival 79 +/- 7%), a marked radiosensitization manifested by a 1.25 +/- .07-fold reduction in the Dq was observed concomitant with a 49 +/- 4% decrease in GR activity. Using cells enriched in different stages of the cell cycle, BCyNU caused cell-age dependent cytotoxicity with preferential killing of cells in the radioresistant late-S-phase, a likely explanation for its radiosensitizing capabilities at high drug dosages. Data obtained at nontoxic drug dosages suggest that GR-inactivation may be an important component of cellular response to free-radical induced damage.

Animals

Stress, appraisal, and coping in mothers of disabled and nondisabled children.

The cognitive-behavioral model of stress and coping provided the framework for this study of mothers of physically disabled children (n = 69) and mothers of nondisabled children (n = 63). The first aim was to test for differences between groups in responses to stressful parenting events. As hypothesized, mothers of disabled children reported higher levels of depressive symptomatology. Differences in psychological distress and health status approached significance. The second aim was to explore the mediating influences of coping strategies and cognitive appraisals. As predicted, emotion-focused coping was related to increased psychological distress in mothers of disabled children whereas problem-focused coping was associated with decreased distress. Both relationships were significant even after controlling for differences in type of parenting stressor. Hierarchical regressions showed that 58 and 25% of the variance in psychological distress was explained by the independent variables; however, the predictors were different for the two groups of mothers. Factors that may explain the differential effectiveness of coping and appraisal, and clinical implications of this study are discussed.

Adaptation, Psychological

Early clinical differentiation between Legionnaires' disease and other sporadic pneumonias.

Early diagnosis of Legionnaires' disease is difficult because other pathogens cause a similar clinical picture and microbiologic tests are usually only of retrospective value. Since May 1977, 17 patients with sporadic cases of Legionnaires' disease have been admitted, all previously well, the diagnosis being made with standard serologic or bacteriologic criteria. From the clinical, laboratory, and radiologic findings, we propose criteria that may enable the clinician to make a diagnosis earlier in many cases, differentiating them from other pneumonias. Within 24 hours of admission, any three of the following four features are strongly suggestive of Legionnaires' disease: [1] prodromal "viral" illness, [2] dry cough or confusion or diarrhoea, [3] lymphopenia without marked neutrophilia, [4] hyponatremia. Two thirds of cases had at least three of these features, and no false-positive diagnoses would have been made in other pneumonias that were serologically negative for Legionnaires' disease if these proposed criteria had been applied diagnostically. In the next few days the diagnosis is very likely if microbiologic tests are negative and if there is radiologic extension, abnormal liver function test results, or hypoalbuminemia.

Adult

Legionnaires' disease: a clinical description of thirteen cases.

We describe 13 patients with legionnaires' disease in Nottingham, all presenting with lobar pneumonia. Six patients required artificial ventilation and 2 died. No common source of infection has yet been identified, but the disease appears to be prevalent and possibly endemic in this city.

Adult

A comparative trial of hyposensitization in 1973 in the treatment of hay fever using Pollinex and Alavac-P.

A direct comparison was made in 112 hay fever patients of hyposensitization treatment with glutaraldehyde-pollen-tyrosine adsorbate (Pollinex) and with alum-precipitated pyridine extract (Alavac-P) which is an accepted form of treatment, its efficacy having been shown by a comparative trial against a placebo preparation. No significant difference could be detected between the results of the two forms of treatment. Seventy-seven per cent of patients responded with improvement following treatment with the tyrosine adsorbed vaccine, and 81% of those receiving the alum-precipitated vaccine. Side effects from treatment, both local and general, were generally of an infrequent or mild nature for both vaccines.

Adolescent

A trial of hyposensitization in 1974/5 in the treatment of hay fever using glutaraldehyde-pollen-tyrosine adsorbate.

One hundred patients with hay fever were treated in 1974/5 with a glutaraldehyde-pollen-tyrosine adsorbate, the response to treatment being assessed at the end of the hay fever season by direct questioning of the patient and examination of a daily record card. Successful results of treatment were recorded in 73% of all patients, results for both years being similar both for patients who had been previously hyposensitized and for those who had not previously received this form of treatment. Side reactions to treatment were generally infrequent or mild, and in only one patient was it necessary to discontinue treatment due to side reactions.

Adolescent

D. pteronyssinus-tyrosine adsorbate: biological and clinical properties.

Adsorption of D. pteronyssinus on tyrosine gives a depot formulation with retained immunogenicity. Preliminary clinical evaluation of this material showed improvement in the majority of allergic subjects after receipt of the initial six doses, improvement being continued during subsequent maintenance therapy.

Adsorption

Chromosome polymorphism and banding patterns in the owl monkey (Aotus).

Diploid numbers, chromosome morphology, G- and C-banding characterisitics and pelage phenotypes were studied in 330 owl monkeys (Aotus) captured and exported from several parts of South America. Among these animals, seven distinctive karyotypes were recognized by the number of chromosomes and their individual identification by G- and C-banding methods. These seven karyotypes were distributed among four distinctive phenotypes differentiated by color patterns in the pelage. These specific phenotypes were designated in this study with capital letters (A through D) and the karyotypes by Roman numerals (I-VII), followed in parentheses by their diploid number. Specimens with phenotype A originated from Brazil and their karyotypes all conformed to a type designated karyotype I (2n=54). Animals classified as having phenotype B were exported from Colombia and their karyotypes were designated as karyotypes II (2n=54), III (2n=53), IV (2n=52), and V (2n=46). Monkeys received from Peru were designated as phenotype C and karyotype VII (2n=52). A group of owl monkeys received from Bolivia were designated as having karyotype VI (2n=50 male; 2n=49 female). Their distinctive phenotype was labeled D. All males in this sample had a diploid number of 49 and the Y-chromosome was translocated to an autosome.

Animals

A distraction technique for control of burn pain.

Research has indicated that analgesics alone do not adequately relieve pain for 75% of patients with burns. The purpose of this study was to determine the effects of a distraction therapy, in which videos were used in combination with administration of analgesics, on intensity and quality of pain and on levels of anxiety in adults during burn dressing changes. The sample consisted of 17 patients who were randomly assigned to the treatment or the control group. The treatment group viewed video programs that were composed of scenic beauty accompanied by music. Each was asked to score his or her present pain intensity and pain rating index with the McGill questionnaire and anxiety with the Spielberger questionnaire before and after the dressing change. A nested general linear model using the "F" test in multiple regression analysis was adjusted for age, percent partial-thickness burn, and choice of topical agent demonstrated that the use of videos during the dressing changes significantly reduced pain and anxiety: present pain intensity (F = 8.69; p = 0.01), pain rating index (F = 5.57; p = 0.03), anxiety (F = 9.10; p = 0.01). It is recommended that the use of pain medication be augmented by use of videos during burn dressing changes.

Adult

Writing man-machine dialogues for a MUMPS system using the Application Controller Language (ACL).

The Application Controller Language (ACL) was designed to facilitate the development of man-machine dialogues. An exact specification of such a dialogue before programming begins is unlikely to be implemented without many changes. Immediately a dialogue is used, the 'hands-on' experience suggests many improvements. ACL was designed to serve as a flexible tool to enable easy re-shaping of this dialogue. For this reason, ACL is structured, allows documentary comments, and may be easily edited. ACL complements MUMPS and encourages the writing of small modular MUMPS programs to carry out well-defined tasks. For this purpose, ACL serves as the 'top' of a top-down written structure, with calls to MUMPS programs being made from ACL statements. A smooth dialogue is made easier to achieve by having all ACL statements use a single I/O processor giving a uniform terminal behaviour and appearance to the display. The programmer is encouraged to call this same I/O processor from his MUMPS application programs. ACL was used extensively for the development of a data management systems for hospital critical care.

Computers