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Biomedical subjects

M O'Malley

Publications and source records attributed to M O'Malley.

At least 19 recordsLinked to original sources
PubMed2000

The role of physician recommendation in women's mammography use: is it a 2-stage process?

OBJECTIVE: To explore the use of a 2-stage model in explaining the role of physician recommendation in women's use of mammography screening and to provide an integrated framework for understanding the mammography-use process. METHODS: Data on 1,301 women aged > or =52 years from the North Carolina Breast Cancer Screening Program (NC-BCSP) questionnaire were combined with information from 91 of their physicians from the North Carolina Medical Board. A 2-stage system of equations using women's characteristics (demographic, health, access), physicians' characteristics (demographic, practice), women's beliefs, and women's report of a physician recommendation was created and statistically tested. The model was estimated using 2-stage logistic and probit estimation. RESULTS: The 2-stage approach produced different results compared with the single pooled model. In the second-stage mammography-use model, younger age, family history of breast cancer, and a woman's having ever requested a mammogram retained significance (P < or = 0.05) in addition to the predicted value of physician recommendation obtained from the first stage. Women's characteristics significantly associated with physician recommendation in the first stage included some access, health risk, and demographic variables as well as physician age and race (P < or = 0.05). CONCLUSIONS: A 2-stage model for estimating mammography use among women with regular physicians may be more informative than a single model. These results imply that programs designed to increase mammography rates should focus on ensuring appropriate physician recommendations in addition to encouraging women to request screening. Future research should consider using an integrated framework for evaluating utilization of mammography and other preventive services.

Breast Neoplasms↗
PubMed2000

MR imaging of renal masses interpreted on CT to be suspicious.

OBJECTIVE: Prior studies have shown that renal MR contrast enhancement improves the efficacy of mass and proximal vascular evaluation. This study assessed the usefulness of different sequences for characterization of masses that appeared suspicious on CT and for prediction of their potential for malignancy. SUBJECTS AND METHODS: In a prospective manner 32 patients (age range, 26-78 years: average age, 54 years), each with at least one suspicious mass on CT, were examined with MR imaging. The following sequences were performed: conventional spin-echo with and without fat saturation, fast spin-echo, and dynamic gadopentetate dimeglumine-enhanced infusion using a 1.5-T superconducting magnet. Results were analyzed and compared with pathologic results after resection. RESULTS: A total of 65 renal masses of average size 2.6 cm (range, 1-10 cm) were detected with dynamic MR imaging. Seventeen of the 65 masses were malignant. Of the 17 malignant masses, three did not enhance on dynamic MR imaging (because of hemorrhage). Sixteen of the 17 malignant masses were heterogeneous on T2-weighted images. Three enhancing masses contained fat and all were angiomyolipomas. Thirty-five of the 65 masses (four with hemorrhage) did not show enhancement, all of which were homogeneous on T2-weighted images and were proven to be cysts. Five masses resulted from infections and had heterogeneous T2 appearance. The remaining masses were three hematomas with hemorrhage, one column of Bertin, and one aneurysm. CONCLUSION: Renal masses that are interpreted as suspicious on CT may lack MR enhancement because of hemorrhage effects; heterogeneity of their T2 appearance is thus critical in differentiating malignancy from benign disease. Odds-ratio calculations give an adjusted estimate of a 3.36-fold increase (95% confidence interval, 1.8-6.27) in the likelihood of malignancy when masses are heterogeneous on T2-weighted images and a 29-fold increase (95% confidence interval, 3.67-241.8) for predicting malignancy when enhancement is present.

Adult↗
PubMed1998

Electrospray ionization and matrix-assisted laser desorption/ionization Fourier transform ion cyclotron resonance mass spectrometry of permethylated oligosaccharides.

Mass spectra of fragments of permethylated oligosaccharides are analyzed by Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometry. Sustained off-resonance irradiation (SORI) collision-induced dissociation (CID), quadrupolar axialization, multiple stages of isolation and dissociation (MSn), and ion remeasurement are exploited for carbohydrate structural analyses. That SORI CID internal energies are adequate for linkage analysis of a permethylated glucose oligomer is demonstrated by identifying ring-opened fragment ions from MALDI-generated mass-isolated and collisionally activated ions. Ion remeasurement and axialization techniques enhance the sensitivity of ion fragmentation analysis. Multiple stages of isolation and dissociation of ion fragments (MSn) provide for structural analysis of an electrospray-ionized permethylated lacto-N-fucopentaose isomer (LNFP II). Compared to MS2 spectra taken with a triple quadrupole, FT-ICR MSn (n > 2) provides more extensive characterization of the parent molecular structure than is available from a single stage of ion isolation and dissociation (MS2).

Carbohydrate Sequence↗
PubMed1998

A review of the effects of moderate alcohol intake on psychiatric and sleep disorders.

In this chapter we discuss the effects of moderate ethanol consumption on the treatment of psychiatric and sleep disorders. A review of the literature on the interactions of ethanol with neurotransmitters and psychotropic medications suggests that although ethanol affects the clinical course of psychiatric and sleep disorders by different mechanisms, it does so principally through perturbations it causes in the balance of central nervous system neurotransmitter systems, which may modify the clinical course of primary psychiatric and sleep disorders and undermine the therapeutic response to psychotropic medications. Neurotransmitter responses may also be manifested clinically by rebound phenomena, akin to a subsyndromal withdrawal, which affect sleep and precipitate anxiety and mood symptoms. In addition, ethanol also modifies the clearance and disposition of a variety of psychotropic metabolites and interferes with their clinical effectiveness. We recommend that most psychiatric patients, and all patients with sleep disorders, should abstain from even moderate ethanol use, as this may adversely affect their clinical course and response to treatment.

Alcohol Drinking↗
PubMed1998

Acute 3,4-methylenedioxymethamphetamine(MDMA) administration produces a rapid and sustained suppression of immune function in the rat.

(+)-3,4-Methylenedioxymethamphetamine (MDMA;'Ecstasy') is a ring substituted phenylisopropylamine that is structurally related to both amphetamines and hallucinogens. The unique behavioural activating properties of MDMA have led to its widespread abuse. MDMA induces many neurochemical, behavioural and endocrine alterations which closely resemble those elicited by exposure to acute stress, suggesting that MDMA could be regarded as a 'chemical stressor'. In addition to the neurochemical, behavioural and endocrine effects of stressor exposure, it has been reported that stress produces alterations in immune function. However, to date the effects of MDMA on immune function have been restricted to in vitro investigations. In this study we report, for the first time, that acute in vivo administration of MDMA (20 mg/kg, i.p.) produced a rapid (within 30 min) suppression of Con A-induced lymphocyte proliferation and a profound reduction in the total leucocyte count in rats that persisted for at least 6 h following injection. These alterations in immune function were accompanied by a significant increase in plasma corticosterone concentrations 30 min post MDMA administration which had returned to baseline values within 6 h of drug administration. In addition, there was a significant depletion in cortical 5-HT concentrations both 30 min and 6 h after MDMA administration. The results of this study provide evidence that in addition to the well established toxic effects of MDMA on the central serotonergic system, a single administration of this widely abused drug induces a rapid and sustained suppression of immune function.

Animals↗
PubMed1998

Physicians' recommendations for colon cancer screening in women. Too much of a good thing?

BACKGROUND: Expert groups support periodic colorectal cancer (CRC) screening for persons aged 50 and older but not for persons younger than 50. We were interested in community primary care physicians' recommendations to women for fecal occult blood tests (FOBT), flexible sigmoidoscopy (SIG), and colonoscopy (COL). METHODS: In a mailed survey of 1,292 community primary care physicians in North Carolina, we queried physicians regarding their recommendations to women for CRC screening. RESULTS: Analysis was performed on 508 respondents (39%). Recommendation for FOBT (96%) and SIG (69%) for women > 50 years old was high among all subgroups of physicians. Recommendation for women < 50 years old was high for FOBT (82%) but lower for SIG (28%). Overall, 19% of physicians recommended COL. Recommendation for FOBT, SIG, and COL varied by physician specialty, physician age, perceived patient demand, physician need for additional CRC screening information, practice size, and location. CONCLUSIONS: Although increasing physician recommendation for CRC screening is important, primary care physicians report recommending earlier and more aggressive screening than that supported by national guidelines.

Adult↗
PubMed1998

An unusual exposure to methyl bromide leading to fatality.

INTRODUCTION: Methyl bromide has been responsible for deaths that usually occur from its accidental inhalation during fumigation. CASE REPORT: We report an accidental fatality that occurred after methyl bromide seeped through underground conduits from a fumigated building to an adjacent guest house on the same property. The patient developed refractory seizures, intermittent fever, and multiorgan system failure before dying 19 days after exposure. The initial serum bromide was 27 mg/dL. Postmortem analysis detected methyl bromide concentrations of 2.9 mg/dL in the blood, 1.7 mg/dL in the bile, 24 micrograms/g in the liver, and 28 micrograms/g in the adipose tissue. CONCLUSION: Methyl bromide, although applied under acceptable safety standards, led to the inadvertent death of a young woman. Extreme care must be used when fumigating to insure no unsuspected seepage routes exist.

Adult↗
PubMed1997

Clinical evaluation of pesticide exposure and poisonings.

Pesticide exposures cause disorders varying from straightforward topical irritant reactions, such as those to synthetic pyrethroid insecticides, to complex systemic illness, such as that resulting from cholinesterase inhibition by organophosphate pesticides. The acute illness syndromes associated with pesticides most commonly encountered by clinicians are illustrated here by cases reported to the California Pesticide Illness Surveillance Program. The issues raised include asthma associated with exposure to contaminants in organophosphate insecticides, systemic toxicity of ingested pyrethroids (in children), and illnesses associated with spills or misuse of fumigants.

Carbamates↗
PubMed1997

Central giant cell granulomas of the jaws: phenotype and proliferation-associated markers.

Central giant cell granulomas (CGCGs) are jaw tumors of unknown origin that often exhibit an aggressive, though unpredictable, clinical course. The purpose of this study was to determine the immunoprofile of the mononuclear cells that seem to be responsible for the biologic behavior of these tumors. Numbers of cells in cell cycle were also determined and compared in clinically aggressive and non-aggressive CGCGs. Sixteen aggressive and 12 non-aggressive CGCGs were immunohistochemically stained with antibodies to CD34, CD68, factor XIIIa, alpha-smooth muscle actin, prolyl 4-hydroxylase, Ki-67, and p53 protein. Cell populations and numbers of cells in cell cycle were determined through microscopic quantitative assessment. CD34-positive cells were limited to support vessels. CD68-positive mononuclear cells constituted a small population of cells in all tumors. With two exceptions, factor XIIIa-positive cells were rarely seen. Alpha-smooth muscle actin staining was present in approximately half the tumors, and occasionally large numbers of positive cells were seen. Most mononuclear cells were positive for fibroblast-associated antigen. No phenotypic differences were detected between aggressive and non-aggressive tumors. P53 protein did not appear to be overexpressed in CGCGs. Ki-67 staining showed that only mononuclear cells were in cell cycle, and that there were no differences between aggressive and non-aggressive tumors. We conclude that CGCGs are primarily fibroblastic (and myofibroblastic) tumors in which macrophages appear to play a secondary role. Tumor cells show no differentiation toward endothelial cells or macrophage-related dendrocytes (factor XIIIa). Cellular phenotypes and numbers of cells in cell cycle are similar in both aggressive and non-aggressive tumors.

Actins↗
PubMed1997

MR urography.

Developments of MR imaging of static fluid has led to the emergence of MR urography (MRU) as a potential imaging technique of the urinary system. MRU has been shown to be highly sensitive in the diagnosis of urinary obstruction, defining the severity of dilatation, the site, and in the majority of cases, the cause of obstruction. At the current level of resolution, however, MR cannot consistently demonstrate nonobstructive or small obstructing calculi. Demonstration of perinephric and periuretic edema in obstruction helps in the differentiation of acute from nonacute urinary obstruction. MRU has shown potential in the work-up of urinary disease for which intravenous urography used to be performed, without the hazards of intravenous contrast administration.

Humans↗
PubMed1997

Streamlining the perioperative process.

Health-care reform and capitated reimbursements have and will continue to influence decreased lengths of hospital stay and continued efficiency in perioperative nursing practice. Collaborative efforts by perioperative nurses, anesthesia care providers, and surgical staff should continue to emphasize concise documentation processes as well as comprehensive assessment and evaluation phases to prepare patients and families for earlier discharge and recovery at home. The objective of new documentation practices and streamlining perioperative preparation processes is to eliminate the duplication of information, meet standards set by professional organizations, and provide quality, efficient care along with patient and family satisfaction.

Anesthesia↗
PubMed1996

MR imaging of tibial plateau fractures.

Magnetic resonance (MR) images of five patients with acute tibial plateau fractures are presented and correlated with both clinical examination and findings at surgical intervention. The role of MR imaging in the evaluation of both osseous and soft tissue deformity in acute trauma, specifically in patients with tibial plateau fractures is discussed. The value of MR imaging as an alternative to computed tomography and arthroscopic evaluation of these patients is emphasized.

Adult↗
PubMed1996

Chlorothalonil, a possible cause of erythema dyschromicum perstans (ashy dermatitis).

We studied 39 patients with erythema-dyschromicum-perstans-like dermatitis seen at Changuinola Hospital in Panama. They were compared with 41 controls. The 2 groups were native field workers of the banana plantations exposed to many pesticides. In 34 patients, there was a positive patch test reaction to 2,4,5,6-1,3-tetrachloroisophthalonilnitrile (chlorothalonil, TCPN) 0.001% in acetone. In 39 cases, biopsies showed a lichenoid tissue reaction compatible with a chronic pigmented dermatitis or erythema-dyschromicum-perstans-like dermatitis. Chlorothalonil is possibly the cause of the pigmented dermatitis observed in the 39 banana farm workers studied. Until additional studies are carried out, we consider this a possible rather than definite cause-and-effect relationship.

Adult↗
PubMed1996

A review of the effects of moderate alcohol intake on the treatment of anxiety and mood disorders.

BACKGROUND: There is no published review to help the clinician clarify the potential role of moderate ethanol consumption in patients being treated for anxiety and mood disorders. Product labels and textbook chapters routinely warn the individual against the consumption of ethanol when using prescription psychotropic drugs. A general understanding is that the reason for this recommendation is the potential for adverse synergistic effects or sedation and decreased psychomotor performance. What is overlooked by this emphasis on safety is the effect of alcohol use both on the underlying psychiatric disorder being treated and on the effectiveness of drug therapy. METHOD: We review the available literature on the interactions of ethanol with neurotransmitters and psychotropic medications and explore the clinical consequences of these interactions. RESULTS: Ethanol might affect anxiety and mood disorders by different mechanisms. Principal among these are the effects of ethanol on multiple neurotransmitter systems, which adapt in different ways to the acute and/or chronic presence of ethanol. Perturbations in the balance of CNS neurotransmitter systems may modify the acute clinical course of primary mood disorders and undermine the therapeutic response to psychotropic medications. Ethanol also modifies the clearance and disposition of psychotropic metabolites and interferes with their clinical effectiveness. Neurotransmitter responses may additionally be manifested clinically by rebound phenomena, akin to a subsyndromal withdrawal, which affect sleep and precipitate anxiety and mood symptoms. Recent alcohol use also may alter the subjective interpretation of the patient's "internal milieu," causing confusion and eliciting reactive psychopathology. CONCLUSION: While much research remains to be done, there is abundant evidence that patients with mood and anxiety disorders should abstain from even moderate ethanol use, as this adversely affects their clinical course and response to treatment.

Alcohol Drinking↗
PubMed1995

Negative radioisotope bone scan in a patient with a fractured neck of femur.

Radioisotope bone scanning is a sensitive and specific method of detecting occult fractures of the femoral neck but may occasionally give false negative results. It would appear that patients with renal failure are more likely to have a false negative test and this is probably related to avascularity of the femoral head.

False Negative Reactions↗
PubMed1994

Superantigenic staphylococcal exotoxins induce T-cell proliferation in the presence of Langerhans cells or class II-bearing keratinocytes and stimulate keratinocytes to produce T-cell-activating cytokines.

Several staphylococcal toxins are among a growing number of immunostimulatory molecules called "superantigens" because of their ability, when presented by appropriate major histocompatibility complex class II+ accessory cells, to activate essentially all T cells bearing particular T-cell receptor V beta gene segments. We have examined the ability of murine epidermal Langerhans cells and/or keratinocytes to act as accessory cells in the T-cell response to the superantigens staphylococcal enterotoxin B and exfoliative toxin, also known as epidermolysin. Purified murine splenic T cells were stimulated with staphylococcal enterotoxin B or exfoliative toxin in the presence of Langerhans cells--enriched epidermal cells from normal mice or epidermal cells isolated from mice pretreated with recombinant interferon-gamma, a procedure that induces the expression of major histocompatibility complex class II molecules on keratinocytes. The data show that both Langerhans cells and class II-bearing keratinocytes can act as accessory cells in the T-cell response to staphylococcal enterotoxin B and exfoliative toxin. We also observed that both human and murine keratinocytes cultured in the presence of staphylococcal enterotoxin B or exfoliative toxin produce increased amounts of cytokine(s) capable of stimulating thymocytes and D10 cells, and that this toxin activity is independent of the level of expression of class II on keratinocytes. Studies by enzyme-linked immunosorbent assay showed that staphylococcal enterotoxin B stimulates keratinocytes to produce tumor necrosis factor-alpha but not interleukin-1, suggesting tumor necrosis factor-alpha and perhaps other cytokines are responsible for the T-cell proliferative activity. These results demonstrate that two distinct epidermal constituents (i.e. Langerhans cells and keratinocytes) can serve as accessory cells in the responses of T cells to superantigenic bacterial toxins. It is possible that such toxins contribute to the pathogenesis of a variety of skin diseases by either locally activating T cells bearing particular V beta genes and/or enhancing keratinocyte production of immunomodulatory cytokines.

Animals↗