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M A Quigley

Publications and source records attributed to M A Quigley.

35 records · Page 2Linked to original sources
PubMed2000

Mapping functionally related regions of brain with functional connectivity MR imaging.

BACKGROUND AND PURPOSE: In subjects who are performing no prescribed cognitive task, functional connectivity mapped with MR imaging (fcMRI) shows regions with synchronous fluctuations of cerebral blood flow. When specific tasks are performed, functional MR imaging (fMRI) can map locations in which regional cerebral blood flow increases synchronously with the performance of the task. We tested the hypothesis that fcMRI maps, based on the synchrony of low-frequency blood flow fluctuations, identify brain regions that show activation on fMRI maps of sensorimotor, visual, language, and auditory tasks. METHODS: In four volunteers, task-activation fMRI and functional connectivity (resting-state) fcMRI data were acquired. A small region of interest (in an area that showed maximal task activation) was chosen, and the correlation coefficient of the corresponding resting-state signal with the signal of all other voxels in the resting data set was calculated. The correlation coefficient was decomposed into frequency components and its distribution determined for each fcMRI map. The fcMRI maps were compared with the fMRI maps. RESULTS: For each task, fcMRI maps based on one to four seed voxel(s) produced clusters of voxels in regions of eloquent cortex. For each fMRI map a closely corresponding fcMRI map was obtained. The frequencies that predominated in the cross-correlation coefficients for the functionally related regions were below 0.1 Hz. CONCLUSION: Functionally related brain regions can be identified by means of their synchronous slow fluctuations in signal intensity. Such blood flow synchrony can be detected in sensorimotor areas, expressive and receptive language regions, and the visual cortex by fcMRI. Regions identified by the slow synchronous fluctuations are similar to those activated by motor, language, or visual tasks.

Adult↗
PubMed1999

Diagnostic accuracy of physician review, expert algorithms and data-derived algorithms in adult verbal autopsies.

BACKGROUND: The verbal autopsy (VA) is used to collect information on cause-specific mortality from bereaved relatives. A cause of death may be assigned by physician review of the questionnaires, or by an algorithm. We compared the diagnostic accuracy of physician review, an expert algorithm, and data-derived algorithms. METHODS: Data were drawn from a multicentre validation study of 796 adult deaths that occurred in hospitals in Tanzania, Ethiopia, and Ghana. A 'gold standard' cause of death was assigned using hospital records and death certificates. The VA interviews were carried out by trained fieldworkers 1-21 months after the subject's death. A cause of death was assigned by physician review and an expert algorithm. Data-derived algorithms that most accurately estimated the cause-specific mortality fraction (CSMF) for each cause of death were identified using logistic regression. RESULTS: The most common causes of death were tuberculosis/AIDS (CSMF = 18.6%), malaria (CSMF = 10.7%), meningitis (CSMF = 8.3%), and cardiovascular disorders (CSMF = 8.2%). The CSMF obtained using physician review was within +/-20% of the gold standard value for 12 causes of death including the four common causes. The CSMF obtained using the expert algorithm was within +/-20% of the gold standard for eight causes of death, including tuberculosis/AIDS, malaria, and meningitis. The CSMF obtained using the data-derived algorithms was within +/-20% of the gold standard for seven causes of death, including tuberculosis/ AIDS, meningitis, and cardiovascular disorders. All three methods yielded a specificity of at least 80% for all causes of death, and a sensitivity of at least 80% for deaths due to injuries and rabies. CONCLUSIONS: For those settings where physician review is not feasible, expert and data-derived algorithms provide an alternative approach for assigning many causes of death. We recommend that the algorithms proposed herein are validated further.

Acquired Immunodeficiency Syndrome↗
PubMed1999

The immune response to Mycobacterium tuberculosis in HIV-infected and uninfected adults in Uganda: application of a whole blood cytokine assay in an epidemiological study.

SETTING: Out-patient clinic, Entebbe, Uganda. BACKGROUND: It has been proposed that 'type 1' cytokines are essential in protective immunity to Mycobacterium tuberculosis and that suppression of 'type 1' or a switch to a 'type 2' profile is deleterious. We employed a simple assay to examine whether the dependence of the immunological responses to mycobacterial antigens on a range of explanatory factors could be determined in a population where tuberculosis is endemic. OBJECTIVE: To determine the relationship between the tuberculin skin test response and cytokine profile, and the effect of human immunodeficiency virus (HIV) infection. DESIGN: A cross-sectional study of 97 Ugandan adults (22 HIV-positive, 75 HIV-negative). Whole blood was stimulated in vitro using mycobacterial antigens (purified protein derivative [PPD] and culture filtrate proteins [CFP]). 'Type 1' cytokines (gamma interferon [IFN-gamma] and interleukin-2 [IL-2]), 'type 2' cytokines (IL-5 and IL-10) and tumour necrosis factor alpha (TNF-alpha) were measured in culture supernatants. RESULTS: Among HIV-negative subjects, a positive tuberculin skin test was associated with type 1 or mixed (type 1 + type 2) cytokine production, but a positive IFN-gamma response also occurred in a proportion of tuberculin skin test negative subjects (36% for PPD, 17% for CFP). In association with HIV infection, IFN-gamma responses to mycobacterial antigens were profoundly impaired (odds ratio [OR] 0.10 for PPD, 0.06 for CFP, P< or =0.001), but production of IL-2, IL-5 and TNF-alpha was relatively sustained, and IL-10 increased or sustained (OR 3.97 for PPD, P = 0.01, 1.14 for CFP, P = 0.99). CONCLUSION: The type 1/type 2 cytokine balance was not defined by the tuberculin skin test response, and may have a closer relation to protective immunity. IFN-gamma production was strikingly impaired in association with HIV infection, while production of type 2 cytokines was sustained or increased. Use of a simple assay allowed a large sample of subjects to be examined, producing epidemiologically meaningful results.

Adolescent↗
PubMed1996

Algorithms for verbal autopsies: a validation study in Kenyan children.

The verbal autopsy (VA) questionnaire is a widely used method for collecting information on cause-specific mortality where the medical certification of deaths in childhood is incomplete. This paper discusses review by physicians and expert algorithms as approaches to ascribing cause of deaths from the VA questionnaire and proposes an alternative, data-derived approach. In this validation study, the relatives of 295 children who had died in hospital were interviewed using a VA questionnaire. The children were assigned causes of death using data-derived algorithms obtained under logistic regression and using expert algorithms. For most causes of death, the data-derived algorithms and expert algorithms yielded similar levels of diagnostic accuracy. However, a data-derived algorithm for malaria gave a sensitivity of 71% (95% Cl: 58-84%), which was significantly higher than the sensitivity of 47% obtained under an expert algorithm. The need for exploring this and other ways in which the VA technique can be improved are discussed. The implications of less-than-perfect sensitivity and specificity are explored using numerical examples. Misclassification bias should be taken into consideration when planning and evaluating epidemiological studies.

Algorithms↗
PubMed1993

Building a managed care approach.

Managed care enhances nursing autonomy and accountability and increases awareness of patients' interactions within a complex multidisciplinary healthcare delivery system. By using this approach, both physicians and nurses are able to assist patients to achieve outcomes quickly, decrease length of hospital stay, and facilitate continuity of care in a cost-effective manner.

Humans↗
PubMed1990

Decreased parietal cell acid secretion after vagotomy is not associated with altered gastric prostaglandin levels.

In a previous investigation we demonstrated that after vagotomy there is a decreased ability of parietal cells to use intracellular cyclic adenosine monophosphate (cAMP). Prostaglandins are present in gastric mucosa and have been demonstrated to be inhibitors of in vivo and in vitro acid secretion through a cAMP-mediated mechanism. In the present study we have examined in vitro acid secretion and prostaglandin E2 levels in rabbits 8 weeks after vagotomy and pyloroplasty compared with control animals to investigate the possible role of prostaglandins in postvagotomy-impaired cAMP use. In vitro acid secretion was assessed in isolated gastric glands by 14C-labeled aminopyrine uptake and prostaglandin E2-generating capacity measured by high-pressure liquid chromatography. After vagotomy, there was a decrease in basal aminopyrine uptake (p less than 0.05), as well as that simulated by histamine and 8-bromo-cAMP (p less than 0.007). No differences were observed in prostaglandin E2 levels in either gastric glands or intact fundic mucosa (p greater than 0.5). These data suggest that impaired cAMP use observed in parietal cells after vagotomy is not the result of alterations in gastric prostaglandin levels.

Aminopyrine↗
PubMed1985

Interpretation and application of world-wide safety data on diltiazem.

The safety of medicinal agents being introduced into the marketplace is of growing concern to consumers, health care providers, and regulatory agencies. Although there are ever increasing efforts to improve techniques for testing drugs, and for anticipating and confirming possible adverse effects, arrangements for monitoring and detecting adverse drug reactions are far from satisfactory. Some factors which need to be understood in order to appropriately interpret data include: maturation processes; pretesting affects, measuring instruments affects; selection bias; and the affects of differential experimental mortality. A safety profile has been presented for the calcium entry blocker diltiazem hydrochloride. Efforts were made to focus attention upon the source of safety information as it relates to the quality of the report. The data presented suggests that diltiazem hydrochloride has a low incidence of adverse experiences.

Adrenergic beta-Antagonists↗
PubMed1981

A survey of selective administration procedures in formulary maintenance.

The survey attempts to examine various Pharmacy and Therapeutics (P & T) Committees' activities for indications of a rational and objective approach to drugs and the hospital formulary. The objectives were: 1) to gain insight as to how drug products attain formulary listing by examining select P & T Committee's reasons for adding and deleting drugs; 2) to determine whether P & T Committees are attempting to follow generally accepted guidelines for the operation of the formulary system; and 3) to determine how the hospital pharmacist is responding to the rational and/or irrational drug selection by the P & T Committee. The results showed that the hospitals studied appeared to be acting in agreement with the guidelines presented. Definitive statements concerning the activities of the pharmacist and the rational approach of the P & T Committee to the hospital formulary could not be made. The author recommends that P & T Committees begin documenting the methods they utilize to promote and maintain the formulary system in hospitals. This information should be used as an educational tool by the P & T Committee.

Formularies, Hospital as Topic↗
PubMedDate not supplied

Managerial interests and personal attributes of nurses.

This study replicated another by Hanson and Chater (1983) that investigated the relationship between interest in management roles and personality, demographic, and career background characteristics of female nurses. For the present study, 128 sophomore, senior, and master's degree students were asked to participate and a self-selected convenience sample of 69 was obtained. Three instruments were used: The Vocational Preference Inventory (VPI), to measure personality traits; a demographic data questionnaire, to measure demographic variables; and the Strong-Campbell Interest Inventory, to measure managerial interests. The total sample of nurses exhibited an artistic-social-intellectual profile. The subhypothesis that nurses of different education levels would exhibit different personality profiles was supported. Analysis of VPI scores demonstrated a statistically significant association between higher educational levels of nurses and higher acquiescence scores, (F = 5.1729 with a significance level of 0.0082). Analysis of variance of Vocational Preference Inventory scale scores showed a statistically significant association between nurses interested in management and higher scores on the enterprising attribute (F = 5.7753 with a significance level of 0.0266). No significant difference was found between management and nonmanagement interest groups in demographic and career characteristics. The findings of this study contribute more insight and knowledge about nurses who select management and administrative roles.

Career Choice↗