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Biomedical subjects

S P Murphy

Publications and source records attributed to S P Murphy.

At least 19 recordsLinked to original sources
PubMed2004

Nutritional changes among premenopausal women undertaking a soya based dietary intervention study in Hawaii.

BACKGROUND: We conducted a 2-year nutritional intervention among premenopausal women. The goal was to incorporate two daily servings of soya into the regular diet. This report describes the dietary modifications and assesses their nutritional adequacy with regard to major nutrients. METHODS: In this analysis of 100 intervention and 106 control subjects, women completed a validated food-frequency questionnaire at baseline; throughout the study, they participated in at least three unannounced 24-h recalls. RESULTS: At randomization, both groups were similar in age and body weight, reported low soya intake, and did not differ by intake of major nutrients and foods. According to the 24-h recalls, women in the intervention group consumed nearly two servings of soya per day, while the control women remained at 0.2 servings. In comparison with the control group, the intervention group consumed fewer dairy products, primarily milk, but also less meat, nuts and seeds. As a result of the dietary modification, the intervention women consumed less-saturated fat and cholesterol and more protein, dietary fibre, calcium and vitamins than the control group. CONCLUSION: These results suggest that women in the intervention group improved the overall quality of their diet by adding two servings of soya per day.

Adult↗
PubMed2001

Evaluation of validity of items for a food behavior checklist.

OBJECTIVES: To evaluate the validity of food behavior items, using a biological measure (serum carotenoids) as the criterion for validity of fruit and vegetable intake, and the results from multiple 24-hour recalls to test convergent validity with nutrient intake. DESIGN: Participants responded to 39 food-behavior questions and later completed three 1-day dietary recalls. Serum carotenoid levels were determined for a 59% randomly selected subsample. SUBJECTS/SETTING: A convenience sample of 100 English-speaking, low-income women participating in a Food Stamp Nutrition Education Program in 8 California counties. Statistical analyses Spearman correlation coefficients were calculated between responses to the food behavior items and (a) serum carotenoid levels and (b) mean nutrient intakes from the 24-hour recalls. Cronbach's coefficient alpha was determined for items within broad food behavior topics. RESULTS: Responses to 10 food behavior items were significantly correlated with serum carotenoid levels (correlations greater than 0.45 were found for choosing low-fat foods and a self-evaluation of overall dietary quality). An additional 12 items showed hypothesized associations with the 24-hour recall data (with a maximum correlation 0.50 for number of eggs per week and dietary cholesterol). Cronbach's coefficient alpha ranged from 0.28 (for 5 fat and cholesterol items) to 0.79 (for 9 fruit and vegetable items). APPLICATIONS/CONCLUSIONS: Nutrition professionals can use these methods to validate items for food behavior checklists for specific populations. The items described here may be useful when designing instruments to administer to low-income women in a community setting.

Adult↗
PubMed2001

Food insecurity is positively related to overweight in women.

Although individuals with poor food security might be expected to have reduced food intake, and thus reduced body fat and less likelihood of being overweight, these associations have not been adequately studied. The purpose of the current study was to examine the relationship between food insecurity and overweight as measured by body mass index (BMI) using data from the nationally representative 1994-1996 Continuing Survey of Food Intakes by Individuals (CSFII). Overweight was defined as BMI >27.3 kg/m(2) for women and 27.8 kg/m(2) for men. Food insecurity was related to overweight status for women (n = 4509, P < 0.0001), but not for men (n = 4970, P = 0.44). Excluding the 11 severely insecure women, the prevalence of overweight among women increased as food insecurity increased, from 34% for those who were food secure (n = 3447), to 41% for those who were mildly food insecure (n = 966) and to 52% for those who were moderately food insecure (n = 86). Food insecurity remained a significant predictor of overweight status, after adjustment for potentially confounding demographic and lifestyle variables (P < 0.01). In a logistic regression analysis, mildly insecure women were 30% more likely to be overweight than those who were food secure [odds ratio (OR) 1.3, P = 0.005]. Thus, food insecurity had an unexpected and paradoxical association with overweight status among women with a higher prevalence of overweight among the food insecure, and a resulting potential for increased incidence of obesity-related chronic diseases. Given that the rates of both overweight and food insecurity are on the rise, this research area warrants further investigation.

Adult↗
PubMed2001

Plastic bottles as spacers for a pressurized metered-dose inhaler: in vitro characteristics.

Homemade spacer devices are commonly used by children with asthma to improve aerosol deposition from pressurized metered dose inhalers (pMDI); however, the efficacy and efficiency of these devices are not fully characterized. We determined the quality of fine particle fraction (< 4.7 microns) and ultrafine particle fraction (< 3.3 microns) of three bottles (from 280 ml to 500 ml) commonly used as spacers in Trinidad and Tobago and compared their performance to the commercially available valved holding chamber (OpT) and pMDI. These data were obtained in vitro using a cascade impactor. All 3 bottles and the OpT were similar (p > 0.05) in reducing the amount of albuterol emitted as large particles (> 4.7 microns) to less than 10 micrograms. The different sized bottles (from 280 ml to 500 ml) produced identical quantities of albuterol in the fine particle and ultrafine particle ranges (p > 0.05). All of the sample bottle spacers emitted a higher amount (p < 0.002) of fine and ultrafine particles than the OpT and pMDI alone. The OpT resulted in a significantly higher fraction of fine particles (p < 0.05) and a greater quantity of drug (p < 0.05) in the ultrafine range as compared to the MDI only. The sizes of particles obtained from the bottle spacers are those that have a high probability of reaching the lower airway; however, the clinical relevance of these findings remains to be determined.

Asthma↗
PubMed2000

Intake of flavonoids and lung cancer.

BACKGROUND: To investigate the possible relationship between intake of flavonoids-powerful dietary antioxidants that may also inhibit P450 enzymes-and lung cancer risk, we conducted a population-based, case-control study in Hawaii. METHODS: An in-person interview assessed smoking history and usual intake of 242 food items for 582 patients with incident lung cancer and 582 age-, sex-, and ethnicity-matched control subjects. Subjects who donated a blood sample were genotyped for the P450 enzyme variant allele CYP1A1*2 by use of a polymerase chain reaction-based method. Logistic regression analysis was used to compute odds ratios (ORs) and 95% confidence intervals (CIs). All P values are two-sided. RESULTS: After adjusting for smoking and intakes of saturated fat and beta-carotene, we found statistically significant inverse associations between lung cancer risk and the main food sources of the flavonoids quercetin (onions and apples) and naringin (white grapefruit). The lung cancer OR for the highest compared with the lowest quartile of intake was 0.5 (95% CI = 0.3-0.9) for onions (P for trend =.001) and 0.6 (95% CI = 0.4-1.0) for apples (P for trend =.03). The OR for the highest compared with the lowest tertile of intake for white grapefruit was 0.5 (95% CI = 0.2-0.9) (P for trend =.02). No association was found for important food sources of other flavonoids. Using published food-composition data for flavonoids, we found an inverse association between intake of quercetin and risk of lung cancer (P for trend =.07) that appears consistent with associations for its food sources. The effect of onions was particularly strong against squamous cell carcinoma (a cell type specifically associated with CYP1A1*2 in our study) and was modified by the CYP1A1 genotype, suggesting that CYP1A1 may play a role in this association. CONCLUSION: If replicated, particularly in prospective studies, these findings would suggest that foods rich in certain flavonoids may protect against certain forms of lung cancer and that decreased bioactivation of carcinogens by inhibition of CYP1A1 should be explored as underlying mechanisms.

Aged↗
PubMed2000

Living arrangements affect dietary quality for U.S. adults aged 50 years and older: NHANES III 1988-1994.

The number and proportion of older U.S. adults who live alone have increased dramatically in the past three decades, and there is concern that these individuals may have particularly poor dietary quality. We examined the association of four living arrangements (living with a spouse only, with a spouse plus someone else, with someone other than a spouse or living alone) with dietary quality (the number of low nutrients out of a possible 15, with low defined as <67% of the recommended dietary allowance) among 6525 U.S. adults aged 50-64 y and those >/=65 y in the third National Health and Nutrition Examination Survey (NHANES III 1988-1994). Among non-Hispanic Caucasian adults, those who lived with a spouse only had better dietary quality, with significant differences ranging from 0.8 to 1.5 fewer low nutrients compared with those with other living arrangements. Effects of living arrangements on dietary quality were also seen among non-Hispanic African-Americans, Mexican-Americans, and those of "other" races, but differences were significant only for African-American men aged >65 y living with a spouse plus others (1.6 additional low nutrients compared with those living with a spouse only). Energy intake was strongly associated with dietary quality, but did not account for the associations between living arrangements and dietary quality. Although middle-aged and older adults with living arrangements other than living with a spouse only (including those living alone) tended to have poorer dietary quality, the effects varied substantially across age, gender and ethnic categories.

Aged↗
PubMed2000

Exhaled nitric oxide as an indicator of severity of asthmatic inflammation.

Traditional assessment of severity of asthma relies on an evaluation of signs and symptoms and pulmonary function tests. These pulmonary function tests, such as peak expiratory flow rates, forced vital capacity, and forced expiratory flow rates, are indirect measures of airway caliber only, and not inflammation. Since asthma is an inflammatory disease, a measure of the degree of inflammation would be helpful in quantitating severity and titrating of anti-inflammatory therapy. A noninvasive method for measuring pulmonary inflammation would therefore be helpful to assist the emergency physician in initial treatment and assist in titration of anti-inflammatory therapy during repeat visits. Exhaled nitric oxide (NO) assays are convenient and practical and may fulfill this role. In this review, we discuss the role of NO in asthmatic inflammation and the role that exhaled NO values may play in the emergency management of asthma.

Asthma↗
PubMed2000

FE(NO): relationship to exhalation rates and online versus bag collection in healthy adolescents.

Measurement of exhaled nitric oxide (FE(NO)) is a noninvasive and practical method for assessing airway inflammation. We conducted this investigation to determine the most appropriate flow rate for FE(NO) measurement and to obtain normal values for FE(NO). We determined which expiratory flow was easy to sustain, generated reproducible values, and provided good correlation between offline and online measurements. Thirty-two healthy subjects (15- 18 yr old) underwent spirometry and FE(NO) measurements, using a chemiluminescent NO analyzer at expiratory flow rates of 46, 31, 23, 15, 10, 7, 5, and 4 ml/s. The major findings were as follows: (1) FE(NO) increased as flow rates decreased, with strong correlation between FE(NO) values and flow rates at the four highest flows (0. 85- 0.93, p < 0.001); (2) there were no significant differences and good agreement between offline bag and online FE(NO) values for the four highest flows (p < 0.09-0.83); (3) online FE(NO) values increased with age 15-17 yr at all flow rates, but decreased at age 18 yr; and (4) using multiple regression, significant predictors of FE(NO) were flow, body surface area, age, and FEF(25-75). On the basis of these results, we provide FE(NO) values for healthy adolescents and propose that the ideal flow rate for children is between 30 and 50 ml/s.

Adolescent↗
PubMed1999

Apoptosis induced by DNA uptake limits transfection efficiency.

Electrotransfection is an effective method for transfecting lymphoid cells. However, the transfection efficiency of certain lymphoid cells is low. L1210 subclones and NFS-70 pro-B cells, which are highly refractory to various transfection methods, were used to identify the limiting factors. Cells were electrotransfected with plasmids coding for green fluorescence protein or luciferase. The luciferase expression of L1210 subclone 3-3 was found to increase 6-12 h after electroporation, but decreased significantly from 12 to 48 h. The lower level of luciferase activity at later time periods correlated with decreases in cell viability, which was shown to be due to apoptosis, as determined by propidium iodide/acrindine orange staining, DNA laddering, and prevention of cell death by addition of caspase inhibitors. Similar results were observed with NFS-70 pro-B cells and select L1210 subclones. In contrast, L1210 parental and L1210 subclone 7-15.6 cells undergo only low levels of apoptosis (< or = 5%). Apoptosis occurred only when DNA (plasmids or salmon sperm DNA) was present during electroporation, but was not dependent on the conformation of the DNA used or the expression of transgenes. Cells pulsed in the presence of dextran sulfate (MW 500,000) did not apoptose. Similar results were observed when L1210 subclone 3-3 was transfected using the cationic lipid 1, 2-dioleoyl-3-trimethylammonium propane, although the transfection efficiency and corresponding rate of apoptosis were significantly lower. Applying the caspase inhibitor fluoromethyl ketone (Boc-ASP-FMK) dramatically improved cell viability and transgene expression of select L1210 subclones and NFS-70 pro-B cells.

Amino Acid Chloromethyl Ketones↗
PubMed1998

Absence of MHC class II antigen expression in trophoblast cells results from a lack of class II transactivator (CIITA) gene expression.

Although the mechanism(s) underlying the failure of the maternal immune system to reject the semiallogeneic fetus have not been clearly defined, the absence of MHC class II antigen expression by fetal trophoblast cells very likely plays a critical role in the maintenance of normal pregnancy. However, the regulation of class II antigen expression in trophoblast cells is poorly understood. Class II transactivator (CIITA) is a transacting factor that is required for both constitutive and IFN-gamma-inducible class II gene transcription. In this report we demonstrate that the inability of trophoblast cells to express class II antigens is due to a lack of CIITA gene expression. Trophoblast cell lines derived from human, mouse, and rat do not express CIITA, and expression is not inducible by IFN-gamma. The absence of CIITA gene expression in trophoblasts treated with IFN-gamma does not result from a defect in the IFN-gamma receptor or the JAK/STAT pathway, because the classical IFN-gamma inducible gene encoding the guanylate-binding protein is expressed. Transfection of CIITA expression vectors into trophoblast cells results in activation of class II promoters, endogenous class II mRNA expression, and subsequent expression of class II antigens on the cell surface. In contrast, class I mRNA is not expressed in human trophoblast cells transfected with CIITA expression vectors. Thus, trophoblast cells contain all of the DNA binding factors necessary for class II transcription, and ectopic expression of CIITA is sufficient to activate class II, but not class I expression. The failure of trophoblast cells to express CIITA, and therefore class II antigens, provides a potential mechanism by which the fetus is protected from the maternal immune system during pregnancy.

Animals↗
PubMed1997

Inducible nitric oxide synthase and nitric oxide production by oligodendrocytes.

It has been previously demonstrated that microglia and astrocytes produce micromolar amounts of nitric oxide in vitro. In this study, we demonstrate that primary rat oligodendrocytes can be stimulated to produce iNOS mRNA as detected by Northern blot and in situ hybridization analysis and a 131-kDa iNOS protein by Western blot analysis; protein was also detected in cells by single- and double-label immunohistochemistry for iNOS and the oligodendrocyte-specific marker CNPase. NO/NOS are produced as a consequence of activation of the gene encoding the inducible nitric oxide synthase as determined by inhibition with actinomycin D and cyclohexamide. The iNOS is functional, leading to calcium/calmodulin-independent NO production in these in vitro cultures.

Animals↗
PubMed1997

Repression of MHC class II gene transcription in trophoblast cells by novel single-stranded DNA binding proteins.

The maintenance of the fetus during pregnancy has been attributed to the absence of major histocompatibility complex (MHC) class II antigens on fetal trophoblastic cells that make contact with the maternal immune system. However, the mechanism(s) by which class II genes are regulated in trophoblast cells is unclear. We have identified a negative regulatory element (IA alpha NRE) in the promoter of the mouse class II gene IA alpha that represses IA alpha transcription in trophoblast cells. IA alpha NRE, located from-839 to -828, binds transacting factors from rat, mouse and human trophoblast cells, but not from 18 other cell lines tested. These results indicate that IA alpha NRE binding proteins (IA alpha NRE BPs) are conserved in species with hemochordial placentas, and suggest that IA alpha NRE binding activity is restricted primarily to trophoblast cells. Interestingly, the IA alpha NRE BPs bind to the IA alpha NRE antisense strand in a sequence-specific manner. IA alpha NRE represses transcription from the IA alpha promoter in a position-dependent manner, and has a minor down-regulatory effect on the activity of the SV40 promoter/enhancer. Our results demonstrate that MHC class II gene transcription is repressed in fetal trophoblast cells by sequence-specific, single-stranded DNA binding proteins, and suggest a possible mechanism by which the conceptus is protected from immune rejection during pregnancy.

Animals↗
PubMed1997

Inflammatory events at the blood brain barrier: regulation of adhesion molecules, cytokines, and chemokines by reactive nitrogen and oxygen species.

Recruitment of inflammatory cells into the CNS during pathological processes associated with neurodegeneration, trauma, autoimmune disease, and infection involves the generation of signaling molecules that are both cell-associated and soluble. Alteration in the permeability of the blood brain barrier, adhesion of blood-borne leukocytes to cerebral vessels, activation of chemoattractants and their receptors, and migration of inflammatory cells into the CNS are events that have been proposed to be regulated by cytokines and reactive oxygen and nitrogen species. In this review we propose associative connections between these events and the molecules involved as they may relate to CNS inflammation, placing illustrative emphasis on multiple sclerosis and the animal model for MS, experimental allergic encephalomyelitis.

Blood-Brain Barrier↗
PubMed1997

Nitric oxide synthase type II expression by different cell types in MHV-JHM encephalitis suggests distinct roles for nitric oxide in acute versus persistent virus infection.

Intranasal inoculation with mouse hepatitis virus strain JHM (MHV-JHM) results in acute meningoencephalitis. We found NOS II mRNA expression in brains of acutely infected animals on days 5 through 7 after infection. In situ hybridization and immunohistochemistry demonstrated NOS II message and protein in infiltrating macrophages. Persistent infection with MHV-JHM results in chronic demyelinating encephalomyelitis. NOS II mRNA was detected in persistently infected spinal cords. In situ hybridization and immunohistochemistry showed expression of NOS II in astrocytes in and around demyelinated lesions. These results suggest the role of NO release in acute versus persistent infection with this virus, and its contribution to the resulting pathology, may be different.

Acute Disease↗
PubMed1997

Neurogenically derived nitrosyl factors mediate sympathetic vasodilation in the hindlimb of the rat.

Skeletal muscle vasculature of the hindlimb is innervated by a sympathetic noncholinergic vasodilator system. The aim of this study was to determine whether this vasodilator system may represent postganglionic lumbar sympathetic neurons that synthesize and release nitric oxide (NO) or related NO-containing factors. We examined whether NO synthase (NOS)-positive postganglionic lumbar nerves innervate the hindlimb vasculature of the rat and whether the hindlimb vasodilation produced by electrical stimulation of the lumbar sympathetic chain of anesthetized rats is reduced after the systemic administration of the specific inhibitor of neuronal NOS 7-nitroindazole (7-NI). Subpopulations of lumbar sympathetic cell bodies stained intensely for NOS. Postganglionic fibers and varicosities within the iliac and femoral arteries also stained for NOS. Double ligation of the lumbar chain demonstrated that NOS was transported from the cell bodies toward the peripheral terminals. Low-intensity electrical stimulation of the lumbar chain produced a pronounced hindlimb vasodilation that was markedly diminished by pretreatment with 7-NI (45 mg/kg i.v.). In contrast, the vasodilator potency of acetylcholine and S-nitrosocysteine were augmented by 7-NI. These results suggest that postganglionic lumbar sympathetic neurons may synthesize and release NO-containing factors.

Acetylcholine↗
PubMed1997

Regulation of gene expression in the nervous system by reactive oxygen and nitrogen species.

Reactive oxygen and nitrogen species function as direct and indirect modulators of gene expression through their interactions with transcription factors and also key enzymes in receptor-activated signalling pathways. This regulatory role may become displaced under certain circumstances such as aging, autoimmune responses and viral infection, leading to the pathological outcome associated with inflammatory and degenerative diseases in the CNS.

Animals↗
PubMed1997

FDG-PET appearance of pelvic Castleman's disease.

We report a case of Castleman's disease demonstrating 18F-fluorodeoxyglucose (FDG) localization by whole-body PET imaging in a pelvic soft-tissue mass shown on abdominopelvic CT. In this case, there is mild FDG localization within pelvic Castleman's disease with standard uptake values lower than in many cases of low-grade and intermediate-grade lymphomas previously reported. FDG-PET may be of value as an imaging modality for differentiating Castleman's disease from lymphoma.

Adult↗