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Patterson AJ, Brown WJ, Roberts DC. Dietary and supplement treatment of iron deficiency results in improvements in general health and fatigue in Australian women of childbearing age. J Am Coll Nutr 2001; 20:337-42. [PMID: 11506061 DOI: 10.1080/07315724.2001.10719054] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
OBJECTIVE To examine the effects of iron deficiency and its treatment by iron supplementation or a high iron diet on fatigue and general health measures in women of childbearing age. DESIGN Randomised controlled trial to compare supplement and dietary treatment of iron deficiency. SUBJECTS 44 iron deficient (serum ferritin < 15 microg/L or serum ferritin 15-20 microg/L, plus two of the following: serum iron < 10 micromol/L, total iron binding capacity > 68 micromol/L or transferrin saturation < 15%) and 22 iron replete (hemoglobin > or = 10 g/L and serum ferritin > 20 microg/L) women 18 to 50 years of age were matched for age and parity. INTERVENTIONS Iron deficient women were randomly allocated to either iron supplementation or a high iron diet for 12 weeks. MEASURES OF OUTCOME Iron deficient and iron replete participants had iron studies performed and completed the Piper Fatigue Scale (PFS) and the SF-36 general health and well-being questionnaire at baseline (T0), following the 12 week intervention (T1) and again after a six-month non-intervention phase (T2). The SF-36 includes measures of physical (PCS) and mental (MCS) health and vitality (VT). RESULTS MCS and VT scores were lower and PFS scores were higher for iron deficient women (diet and supplement groups) than iron replete women at baseline. Both intervention groups showed similar improvements in MCS, VT and PFS scores during the intervention phase, but mean increases in serum ferritin were greater in the supplement than the diet group. PCS scores were not related to iron status. CONCLUSIONS Treatment of iron deficiency with either supplementation or a high iron diet results in improved mental health and decreased fatigue among women of childbearing age.
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Pfister O, Brown WJ, Stenner MD, Gauthier DJ. Polarization instabilities in a two-photon laser. PHYSICAL REVIEW LETTERS 2001; 86:4512-4515. [PMID: 11384271 DOI: 10.1103/physrevlett.86.4512] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2000] [Indexed: 05/23/2023]
Abstract
We describe the operating characteristics of a new type of quantum oscillator that is based on a two-photon stimulated emission process. This two-photon laser consists of spin-polarized and laser-driven 39K atoms placed in a high-finesse transverse-mode-degenerate optical resonator and produces a beam with a power of approximately 0.2 microW at a wavelength of 770 nm. We observe complex dynamical instabilities of the state of polarization of the two-photon laser, which are made possible by the atomic Zeeman degeneracy. We conjecture that the laser could emit polarization-entangled twin beams if this degeneracy is lifted.
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Brown WJ. Immunoperoxidase methods for localization of antigens in cultured cells and tissues. CURRENT PROTOCOLS IN CELL BIOLOGY 2001; Chapter 4:Unit 4.6. [PMID: 18228366 DOI: 10.1002/0471143030.cb0406s01] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
This carefully written unit describes two methods for using the immunoperoxidase reaction to localize antigens at the electron microscope level; one for adherent cultured cells and one for tissue sections. The reaction conditions are first optimized at the light microscope level and then adapted for EM level observation. These methods allow for reliable detection of antigens at the cell surface, within the cell, and especially in membrane bounded organelles. Embedding and staining procedures are also optimized for sample visualization.
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Patterson AJ, Brown WJ, Powers JR, Roberts DC. Iron deficiency, general health and fatigue: results from the Australian Longitudinal Study on Women's Health. Qual Life Res 2001; 9:491-7. [PMID: 11190004 DOI: 10.1023/a:1008978114650] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Associations between self-reported 'low iron', general health and well-being, vitality and tiredness in women, were examined using physical (PCS) and mental (MCS) component summary and vitality (VT) scores from the MOS short-form survey (SF-36). 14,762 young (18-23 years) and 14,072 mid-age (45-50 years) women, randomly selected from the national health insurance commission (Medicare) database, completed a baseline mailed self-report questionnaire and 12,328 mid-age women completed a follow-up questionnaire 2 years later. Young and mid-age women who reported (ever) having had 'low iron' reported significantly lower mean PCS, MCS and VT scores, and greater prevalence of 'constant tiredness' at baseline than women with no history of iron deficiency [Differences: young PCS = -2.2, MCS = -4.8, VT = -8.7; constant tiredness: 67% vs. 45%; mid-age PCS = -1.4, MCS = -3.1, VT = -5.9; constant tiredness: 63% vs. 48%]. After adjusting for number of children, chronic conditions, symptoms and sociodemographic variables, mean PCS, MCS and VT scores for mid-age women at follow-up were significantly lower for women who reported recent iron deficiency (in the last 2 years) than for women who reported past iron deficiency or no history of iron deficiency [Means: PCS--recent = 46.6, past = 47.8, never = 47.7; MCS--recent = 45.4, past = 46.9, never = 47.4; VT--recent = 54.8, past = 57.6, never = 58.6]. The adjusted mean change in PCS, MCS and VT scores between baseline and follow-up were also significantly lower among mid-age women who reported iron deficiency only in the last 2 years (i.e. recent iron deficiency) [Mean change: PCS = -3.2; MCS = -2.1; VT = -4.2]. The results suggest that iron deficiency is associated with decreased general health and well-being and increased fatigue.
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Hodge A, Patterson AJ, Brown WJ, Ireland P, Giles G. The Anti Cancer Council of Victoria FFQ: relative validity of nutrient intakes compared with weighed food records in young to middle-aged women in a study of iron supplementation. Aust N Z J Public Health 2000; 24:576-83. [PMID: 11215004 DOI: 10.1111/j.1467-842x.2000.tb00520.x] [Citation(s) in RCA: 503] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
OBJECTIVE To assess the validity of the Anti Cancer Council of Victoria food frequency questionnaire (ACCVFFQ) relative to seven-day weighed food records (WFRs) in 63 women of child-bearing age. METHOD 63 women completed WFRs to assess iron intake as part of a study on iron deficiency. These women also completed the ACCVFFQ. Nutrient intakes were computed independently for the WFRs and FFQs. Intakes were compared as group means, by correlation and by quintile classification, adjusting for day-to-day variation in intakes, and for energy intake. Individual differences in results were also examined. RESULTS The strongest associations between WFR and FFQ results were energy-adjusted, log-transformed and adjusted for day-to-day variability in intake. Correlation coefficients ranged from 0.28 for vitamin A to 0.78 for carbohydrate. Mean intakes from the WFRs and FFQs were within +/- 20% for 21 of 27 nutrients. Poor agreement between FFQs and WFRs for retinol intake was due to the inclusion of liver in two WFRs, an item which is not included in the FFQ. CONCLUSION The ACCVFFQ performs as well as other FFQs for which validation data are available. The relatively poor measurement of retinol is consistent with other data, and with the limited number of foods in which this nutrient is abundant. IMPLICATIONS The availability of an optically scannable valid instrument for assessing dietary intake will facilitate epidemiological studies of diet and disease, an area of current research priority.
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Brown WJ, Mishra G, Kenardy J, Dobson A. Relationships between body mass index and well-being in young Australian women. Int J Obes (Lond) 2000; 24:1360-8. [PMID: 11093300 DOI: 10.1038/sj.ijo.0801384] [Citation(s) in RCA: 94] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
OBJECTIVE To explore relationships between body mass index (BMI, kg/m2) and indicators of health and well-being in young Australian women. DESIGN Population based cohort study--baseline cross sectional data. SUBJECTS 14,779 women aged 18-23 who participated in the baseline survey of the Australian Longitudinal Study on Women's Health in 1996. MEASUREMENTS Self-reported height, weight, medical conditions, symptoms and SF-36. RESULTS The majority of women (68%) had a BMI in the range 18.5- <25; 12% had a BMI <18.5; 14% had a BMI in the range 25- <30 and 6% had a BMI > or =30. After adjustment for area of residence, age, education, smoking and exercise, women in the highest BMI category (> or =30) were more likely to report hypertension, asthma, headaches, back pain, sleeping difficulties, irregular periods, and more visits to their medical practitioner. They were also more likely to have given birth at least once, and less likely to report 'low iron'. Women with low BMI (<18.5) were more likely to report irregular periods and 'low iron'. Mean scores on the SF-36 sub-scales for physical functioning, general health and vitality were highest for women with BMI in the range 18.5-25. CONCLUSION Acknowledging the limits of the cross-sectional nature of the data, the results show that the deleterious effects of overweight can be seen at a comparatively young age, and that BMI <25 is associated with fewer indicators of morbidity in young women. However, as BMI <18.5 is associated with low iron and irregular periods, care should be taken when developing strategies to prevent overweight in young women, not to encourage women with healthy weight to strive for a lower BMI.
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Brown WJ, Bauman AE. Comparison of estimates of population levels of physical activity using two measures. Aust N Z J Public Health 2000; 24:520-5. [PMID: 11109690 DOI: 10.1111/j.1467-842x.2000.tb00503.x] [Citation(s) in RCA: 120] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
OBJECTIVE To compare estimates of population levels of 'adequate activity' for health benefit in different age and sex groups using two different measures--kilocalories (kcals) and Mets.mins. METHODS 10,464 mid-age women (47-52 years) from the second survey of the Australian Longitudinal Study on Women's Health (ALSWH, 1998) and 2,500 men and women (18-75 years) from the 1997 Active Australia national survey, answered questions about physical activity. Kcals and Mets.mins were calculated from self-reported time spent in walking, moderate and vigorous activity, and self-reported body weight. 'Adequate activity' was defined as a minimum of 800 kcals or 600 Mets.mins. RESULTS There were differences in the estimates of 'adequate activity' using the two methods among women participants in both surveys, but not among the male participants in the Active Australia survey. A significant proportion of the women in both surveys (6.4% of the ALSWH women and 8.5% of the Active Australia women, mean weight 60 kg) were classified as 'inactive' when the kcals method was used despite reporting levels of activity commensurate with good health. Fewer than 1% (mean weight 105 kg) were classified as 'active' using kcals when reporting lower than recommended levels of activity. Agreement between the two methods was better among men; only 3% were misclassified because of low or very high weight. CONCLUSIONS The Mets.mins method of estimating 'adequate' activity assesses physical activity independently of body weight and is recommended for use in future population surveys, as it is less likely to under-estimate the prevalence of physical activity in women. IMPLICATIONS Women and men aged 45-59 and women aged > 60 should be the target of specific health promotion strategies to increase population levels of physical activity.
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Abstract
BACKGROUND Yersinia enterocolitica can cause illness ranging from self-limited enteritis to life-threatening systemic infection. The present study was undertaken to review the epidemiology, clinical manifestations, complications and outcome of Y. enterocolitica enteritis in children seen at a large children's hospital. METHODS The project consisted of a retrospective chart review of medical and microbiologic records of all children with stool cultures positive for Y. enterocolitica during a 7-year period. RESULTS The review included 142 patients with Y. enterocolitica enteritis. Patients' ages ranged from 18 days to 12 years, and the majority (85%) were younger than 1 year. Most patients presented during November, December and January. History of exposure to chitterlings (raw pork intestines) at home was elicited in 25 of 30 cases. Y. enterocolitica accounted for 12.6% (142 of 1,120) of all bacterial intestinal pathogens isolated during the study period. Blood cultures were positive in 7(9%) of 78 patients; 6 were younger than 1 year and one 12-year-old had sickle cell disease. Of 132 isolates tested all were susceptible to trimethoprim-sulfamethoxazole, tobramycin and gentamicin; the majority were susceptible to cefotaxime (99%), ceftazidime (89%) and cefuroxime (88%). All bacteremic patients responded to cefotaxime treatment. Follow-up evaluation of 40 ambulatory patients revealed no difference in clinical improvement between those treated with oral trimethoprim-sulfamethoxazole (17 of 23) and those who were not treated (8 of 17) (P = 0.1). CONCLUSION Y. enterocolitica is an important cause of enteritis in our young patient population during the winter holidays. Exposure of infants to chitterlings appears to be a risk factor. Infants younger than 3 months are at increased risk for bacteremia. Cefotaxime is effective in the treatment of Y. enterocolitica bacteremia; however, the role of oral antibiotics in the management of enteritis needs further evaluation.
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Brown WJ, Mishra G, Lee C, Bauman A. Leisure time physical activity in Australian women: relationship with well being and symptoms. RESEARCH QUARTERLY FOR EXERCISE AND SPORT 2000; 71:206-216. [PMID: 10999258 DOI: 10.1080/02701367.2000.10608901] [Citation(s) in RCA: 152] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
This paper explores the association between moderate levels of physical activity (PA) and health benefits in well being and symptoms such as tiredness, back pain, and constipation. Participants in the Australian Longitudinal Study on Women's Health, 14,502 young women (ages 18-23 years), 13,609 middle-age women (45-50 years), and 11,421 older women (ages 70-75 years), answered questions about vigorous and less vigorous exercise (used to determine a physical activity score), well being (SF-36), symptoms, and medical conditions. There were significant associations between the PA score and SF-36 in each cohort. Odds ratios (OR) for a range of symptoms and conditions were lower for women who reported low to moderate activity than for sedentary women, for example, for young women or for constipation = 0.76 (CI, 0.65-0.89), for middle-age women or for tiredness = 0.70 (0.63-0.78). There was no threshold of PA at which health benefits increased significantly. Although cross-sectional, the findings suggest that low-to-moderate levels of exercise are associated with a range of health benefits for women of all ages. These preliminary findings will be followed up during the longitudinal study.
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de Figueiredo P, Brown WJ. Clofibrate inhibits membrane trafficking to the Golgi complex and induces its retrograde movement to the endoplasmic reticulum. Cell Biol Toxicol 2000; 15:311-23. [PMID: 10813364 DOI: 10.1023/a:1007667802497] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Insights into the function of the Golgi complex have been provided by experiments performed with various inhibitors of membrane trafficking, such as the macrocyclic lactone brefeldin A (BFA), a compound that inhibits constitutive secretion, prevents the formation of coatomer-coated transport vesicles, and stimulates the retrograde movement of Golgi resident enzymes back to the ER. We show here that the structurally unrelated compound clofibrate, a peroxisome proliferator (PP) and hypolipidemic agent, also reversibly disrupts the morphological and functional integrity of the Golgi complex in a manner similar to BFA. In the presence of clofibrate, the forward transport of newly synthesized secretory proteins from the ER to the Golgi is dramatically inhibited. Moreover, clofibrate causes Golgi membranes to travel rapidly in a microtubule-dependent manner back to the ER, forming a hybrid ER-Golgi tubulovesicular membrane network. These affects appear to be independent of clofibrate's ability to stimulate the PP-activated receptor (PPAR) alpha pathway because other PPAR stimulators (DEHP, WY-14643) did not alter the Golgi complex or induce retrograde trafficking. These data suggest that PPAR alpha-independent, clofibrate-sensitive proteins participate in regulating Golgi-to-ER retrograde membrane transport, and, equally importantly, that clofibrate may be used as a pharmacological tool for investigating Golgi membrane dynamics.
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de Figueiredo P, Drecktrah D, Polizotto RS, Cole NB, Lippincott-Schwartz J, Brown WJ. Phospholipase A2 antagonists inhibit constitutive retrograde membrane traffic to the endoplasmic reticulum. Traffic 2000; 1:504-11. [PMID: 11208136 DOI: 10.1034/j.1600-0854.2000.010608.x] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Eukaryotic cells contain a variety of cytoplasmic Ca(2+)-dependent and Ca(2+)-independent phospholipase A2s (PLA2s; EC 2.3.1.2.3). However, the physiological roles for many of these ubiquitously-expressed enzymes is unclear or not known. Recently, pharmacological studies have suggested a role for Ca(2+)-independent PLA2 (iPLA2) enzymes in governing intracellular membrane trafficking events in general and regulating brefeldin A (BFA)-stimulated membrane tubulation and Golgi-to-endoplasmic reticulum (ER) retrograde membrane trafficking, in particular. Here, we extend these studies to show that membrane-permeant iPLA2 antagonists potently inhibit the normal, constitutive retrograde membrane trafficking from the trans-Golgi network (TGN), Golgi complex, and the ERGIC-53-positive ER-Golgi-intermediate compartment (ERGIC), which occurs in the absence of BFA. Taken together, these results suggest that iPLA2 enzymes play a general role in regulating, or directly mediating, multiple mammalian membrane trafficking events.
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Jonas HA, Dobson AJ, Brown WJ. Patterns of alcohol consumption in young Australian women: socio-demographic factors, health-related behaviours and physical health. Aust N Z J Public Health 2000; 24:185-91. [PMID: 10790939 DOI: 10.1111/j.1467-842x.2000.tb00140.x] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
OBJECTIVE To determine which socio-demographic factors, health-related behaviours and physical health conditions are associated with non-drinking, binge drinking and hazardous/harmful drinking in young Australian women. METHODS Cross-sectional data were obtained from the baseline survey of 14,762 young women (aged 18-23 years) enrolled in the Women's Health Australia study in 1996. Associations between a range of drinking patterns and socio-demographic factors, health-related behaviours and health conditions were examined. RESULTS Half the women were 'low intake' drinkers, a third 'rarely drank' and 9% were non-drinkers; however, 70% reported binge drinking with one-quarter of the binge drinkers doing so at least weekly. Non-drinkers were more likely than drinkers to be married, pregnant, non-smokers, born in non-English speaking countries, to live in the Northern Territory, and to have lower levels of education, employment, and private health insurance. 'Low intake/binge weekly' drinkers (12%) and 'hazardous/harmful' drinkers (5%) were more likely than 'low risk' drinkers to be unmarried; to live in shared accommodation, alone or with their parents; to live in rural or remote areas; to have ever had any sexually transmitted infection; to be current smokers or ex-smokers and to have used unhealthy weight-control practices. CONCLUSIONS The results confirm findings from other countries about the importance of social conditions as determinants of alcohol consumption by young women. IMPLICATIONS Health promotion to reduce young women's alcohol consumption needs to be carefully targeted to take account of their demographies, living environments and beliefs.
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Bannantine JP, Griffiths RS, Viratyosin W, Brown WJ, Rockey DD. A secondary structure motif predictive of protein localization to the chlamydial inclusion membrane. Cell Microbiol 2000; 2:35-47. [PMID: 11207561 DOI: 10.1046/j.1462-5822.2000.00029.x] [Citation(s) in RCA: 184] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Chlamydiae are obligate intracellular pathogens that spend their entire growth phase sequestered in a membrane-bound vacuole called an inclusion. A set of chlamydial proteins, labelled Inc proteins, has been identified in the inclusion membrane (IM). The predicted IncA, IncB and IncC amino acid sequences share very limited similarity, but a common hydrophobicity motif is present within each Inc protein. In an effort to identify a relatively complete catalogue of Chlamydia trachomatis proteins present in the IM of infected cells, we have screened the genome for open reading frames encoding this structural motif. Hydropathy plot analysis was used to screen each translated open reading frame in the C. trachomatis genome database. Forty-six candidate IM proteins (C-lncs) that satisfied the criteria of containing a bilobed hydrophobic domain of at least 50 amino acids were identified. The genome of Chlamydia pneumoniae encodes a larger collection of C-lnc proteins, and only approximately half of the C-lncs are encoded within both genomes. In order to confirm the hydropathy plot screening method as a valid predictor of C-lncs, antisera and/or monoclonal antibodies were prepared against six of the C. trachomatis C-lncs. Immunofluorescence microscopy of C. trachomatis-infected cells probed with these antibodies showed that five out of six C-lncs are present in the chlamydial IM. Antisera were also produced against C. pneumoniae p186, a protein sharing identity with Chlamydia psittaci lncA and carrying a similar bilobed hydrophobic domain. These antisera labelled the inclusion membrane in C. pneumoniae infected cells, confirming that proteins sharing the unique secondary structural characteristic also localize to the inclusion membrane of C. pneumoniae. Sera from patients with high-titre antibodies to C. trachomatis were examined for reactivity with each tested C-lnc protein. Three out of six tested C-lncs were recognized by a majority of these patient sera. Collectively, these studies identify and characterize novel proteins localized to the chlamydial IM and demonstrate the existence of a potential secondary structural targeting motif for localization of chlamydial proteins to this unique intracellular environment.
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Brown WJ, Rockey DD. Identification of an antigen localized to an apparent septum within dividing chlamydiae. Infect Immun 2000; 68:708-15. [PMID: 10639437 PMCID: PMC97196 DOI: 10.1128/iai.68.2.708-715.2000] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The process of chlamydial cell division has not been thoroughly investigated. The lack of detectable peptidoglycan and the absence of an FtsZ homolog within chlamydiae suggest an unusual mechanism for the division process. Our laboratory has identified an antigen (SEP antigen) localized to a ring-like structure at the apparent septum within dividing chlamydial reticulate bodies (RB). Antisera directed against SEP show similar patterns of antigen distribution in Chlamydia trachomatis and Chlamydia psittaci RB. In contrast to localization in RB, SEP in elementary bodies appears diffuse and irregular, suggesting that the distribution of the antigen is developmental-stage specific. Treatment of chlamydiae with inhibitors of peptidoglycan synthesis or culture of chlamydiae in medium lacking tryptophan leads to the formation of nondividing, aberrant RB. Staining of aberrant RB with anti-SEP reveals a marked redistribution of the antigen. Within C. trachomatis-infected cells, ampicillin treatment leads to high levels of SEP accumulation at the periphery of aberrant RB, while in C. psittaci, treatment causes SEP to localize to distinct punctate sites within the bacteria. Aberrancy produced via tryptophan depletion results in a different pattern of SEP distribution. In either case, the reversal of aberrant formation results in the production of normal RB and a redistribution of SEP to the apparent plane of bacterial division. Collectively these studies identify a unique chlamydial-genus-common and developmental-stage-specific antigen that may be associated with RB division.
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Diebel LN, Liberati DM, Diglio CA, Dulchavsky SA, Brown WJ. Synergistic effects of Candida and Escherichia coli on gut barrier function. THE JOURNAL OF TRAUMA 1999; 47:1045-50; discussion 1050-1. [PMID: 10608531 DOI: 10.1097/00005373-199912000-00009] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Disruption of the indigenous gut microflora with overgrowth of gram-negative bacteria and Candida species is common in the critically ill patient. These organisms readily translocate in vitro, which may cause septic complications and organ failure. A synergistic effect between Escherichia coli and C. albicans in polymicrobial infections has been demonstrated. An interaction between these organisms at the mucosal barrier is unknown. METHODS Ca(CO2) monolayers were grown to confluence in a two compartment culture system. E. coli and C. albicans or E. coli alone were added to the apical chambers. Secretory immunoglobulin A was added to half of the apical chambers as well. Cell cultures were incubated for a total of 240 minutes. Basal media were sampled at timed intervals for quantitative culture. Monolayer integrity was confirmed by serial measurement of transepithelial electrical resistance. RESULTS Secretory immunoglobulin A decreased bacterial translocation across Ca(CO2) monolayers challenged with E. coli alone. Transepithelial passage of E. coli was significantly increased by coculture of bacteria with C. albicans. Augmentation of bacterial translocation by Candida occurred even in the presence of secretory immunoglobulin A. CONCLUSIONS Candida colonization of the GI tract may impair mucosal barrier defense against gram-negative bacteria. The clinical role of gut antifungal prophylaxis in protecting against gut derived gram-negative sepsis is speculative.
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Drecktrah D, Brown WJ. Phospholipase A(2) antagonists inhibit nocodazole-induced Golgi ministack formation: evidence of an ER intermediate and constitutive cycling. Mol Biol Cell 1999; 10:4021-32. [PMID: 10588640 PMCID: PMC25740 DOI: 10.1091/mbc.10.12.4021] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Evidence has been presented both for and against obligate retrograde movement of resident Golgi proteins through the endoplasmic reticulum (ER) during nocodazole-induced Golgi ministack formation. Here, we studied the nocodazole-induced formation of ministacks using phospholipase A(2) (PLA(2)) antagonists, which have been shown previously to inhibit brefeldin A-stimulated Golgi-to-ER retrograde transport. Examination of clone 9 rat hepatocytes by immunofluorescence and immunoelectron microscopy revealed that a subset of PLA(2) antagonists prevented nocodazole-induced ministack formation by inhibiting two different trafficking pathways for resident Golgi enzymes; at 25 microM, retrograde Golgi-to-ER transport was inhibited, whereas at 5 microM, Golgi-to-ER trafficking was permitted, but resident Golgi enzymes accumulated in the ER. Moreover, resident Golgi enzymes gradually redistributed from the juxtanuclear Golgi or Golgi ministacks to the ER in cells treated with these PLA(2) antagonists alone. Not only was ER-to-Golgi transport of resident Golgi enzymes inhibited in cells treated with these PLA(2) antagonists, but transport of the vesicular stomatitis virus G protein out of the ER was also prevented. These results support a model of obligate retrograde recycling of Golgi resident enzymes during nocodazole-induced ministack formation and provide additional evidence that resident Golgi enzymes slowly and constitutively cycle between the Golgi and ER.
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Polizotto RS, de Figueiredo P, Brown WJ. Stimulation of Golgi membrane tubulation and retrograde trafficking to the ER by phospholipase A(2) activating protein (PLAP) peptide. J Cell Biochem 1999; 74:670-83. [PMID: 10440936] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
Abstract
Recent pharmacological studies using specific antagonists of phospholipase A(2) (PLA(2)) activity have suggested that the formation of Golgi membrane tubules, 60-80 nm in diameter and up to several microns long, both in vivo and in a cell-free cytosol-dependent reconstitution system, requires the activity of a cytoplasmic Ca(2+)-independent PLA(2). We confirm and extend these studies by demonstrating that the stimulators of PLA(2), melittin and PLA(2) activating protein peptide (PLAPp), enhance cytosol-dependent Golgi membrane tubulation. Starting with preparations of bovine brain cytosol (BBC), or a fraction of BBC that is highly enriched in tubulation activity, called the gel filtration (GF) fraction, that are at subsaturating concentrations for inducing tubulation in vitro, we found that increasing concentrations of melittin or PLAPp produced a linear and saturable stimulation of Golgi membrane tubulation. This stimulation was inhibited by cytosolic PLA(2) antagonists, including the Ca(2+)-independent PLA(2)-specific antagonist, bromoenol lactone. The stimulatory effect of PLAPp, and its inhibition by PLA(2) antagonists, was reproduced using a permeabilized cell system, which reconstitutes both cytosol-dependent Golgi membrane tubulation and retrograde trafficking to the endoplasmic reticulum (ER). Taken together, these results are consistent with the idea that cytosolic PLA(2) activity is involved in the formation of Golgi membrane tubules, which can serve as trafficking intermediates in Golgi-to-ER retrograde movement.
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Polizotto RS, de Figueiredo P, Brown WJ. Stimulation of golgi membrane tubulation and retrograde trafficking to the ER by phospholipase A
2
activating protein (PLAP) peptide. J Cell Biochem 1999. [DOI: 10.1002/(sici)1097-4644(19990915)74:4<670::aid-jcb16>3.0.co;2-#] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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Weingarten CM, Rybak MJ, Jahns BE, Stevenson JG, Brown WJ, Levine DP. Evaluation of Acinetobacter baumannii infection and colonization, and antimicrobial treatment patterns in an urban teaching hospital. Pharmacotherapy 1999; 19:1080-5. [PMID: 10610015 DOI: 10.1592/phco.19.13.1080.31597] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
In 1990 there was a sudden increase in the incidence of colonization and infection due to Acinetobacter baumannii (AB) in our intensive care units (ICUs). The isolates were multiply resistant to beta-lactam and aminoglycoside antibiotics, but remained susceptible to imipenem, amikacin, and ampicillin-sulbactam. We examined the frequency of infection and colonization with AB and the effects of increased imipenem and amikacin therapy on Pseudomonas aeruginosa. We also used disease-matched controls to determine the clinical and financial impacts of treating colonization. All patients with at least one AB isolate from January-December 1992 were identified retrospectively and classified as infected or colonized based on published Centers for Disease Control criteria; the control group was selected from a computerized medical records data base matching primary diagnostic codes (102 patients both groups). The 102 patients yielded 140 isolates, 124 resistant AB and 16 sensitive AB. Thirty three patients were infected, 69 colonized. Mortality correlated with APACHE II scores. Patients acquired the organism approximately 2 weeks after admission; they had a mean ICU stay of 27.35 days, compared with 5.53 days for controls. Patients with positive AB cultures required significantly more use of ventilators than those with negative AB cultures. They also had significantly longer hospital stay, more bed transfers, greater duration and number of antibiotics, and higher hospital and pharmacy charges. Unnecessary treatment for colonization with either imipenem or amikacin resulted in a substantial decrease of P. aeruginosa susceptibility to each agent. The financial impact of treating colonization was significant and is a potential area for cost avoidance. Our results emphasize the need to extubate and move patients to non-ICU beds as soon as possible to decrease the risk of nosocomial infection. It also highlights the need to avoid treating colonization, thus avoiding unnecessary antibiotic therapy.
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Brown WJ, Young AF, Byles JE. Tyranny of distance? The health of mid-age women living in five geographical areas of Australia. Aust J Rural Health 1999; 7:148-54. [PMID: 10745728 DOI: 10.1046/j.1440-1584.1999.00236.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Over 14,000 women aged 45-50 are participating in the Australian Longitudinal Study on Women's Health, which is designed to track the health of Australian women for 20 years, and to understand lifestyle and healthcare factors that influence women's health. The study deliberately overrepresents women from rural and remote areas. This analysis of baseline data from the study compares the responses of women living in urban areas (capital city, other metropolitan), large rural centres, small rural centres, other rural areas and remote areas (remote centres, other remote areas) of Australia. The data show that while women in this age group who live in rural and remote areas have similar levels of self-rated health, they have significantly fewer visits to general practitioners and specialists (P < 0.001) and more visits to alternative healthcare providers than women living in urban areas. Rural and remote area women were also more likely to undergo gynaecological surgery than women living in urban areas (P < 0.001). Other results suggest that being overweight is more common among women from rural and remote areas, and that these women also report lower levels of stress than women from urban areas (P < 0.001). Further follow up will allow any divergence in health and healthcare equity to be explored as these women get older.
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Abstract
The paper aims to (1) assess the prevalence of leaking urine and to (2) explore associations between leaking urine and a variety of other symptoms, conditions, surgical procedures and life events in three large cohorts of Australian women, who are participants in the Australian Longitudinal Study on Women's Health. Young women aged 18-23 (N = 14,000), mid-age women, 45-50 (N = 13,738) and older women, 70-75 (N = 12,417), were recruited randomly from the national HIC/Medicare database. Leaking urine was reported by approximately one in eight young women [estimated prevalence 12.8% (95% CI: 12.2-13.3)] and one in three mid-age women [36.1% (CI: 35.2-37.0)] and older women [35.0% (CI: 34.1-35.9)]. Leaking urine was significantly associated with parity, conditions which increase the pressure on the pelvic floor such as constipation and obesity, past gynecological surgery and conditions which can impact on bladder control. The study showed that fewer than half the women had sought help for the problem and that younger women were less likely to be satisfied with the help available for this problem. Strategies for continence promotion, including opportunistic raising of the issue at the time of cervical screening and pregnancy care are suggested, so that the health and social outcomes of untreated chronic incontinence in women might be improved.
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Brown WJ, Dobson AJ, Bryson L, Byles JE. Women's Health Australia: on the progress of the main cohort studies. JOURNAL OF WOMEN'S HEALTH & GENDER-BASED MEDICINE 1999; 8:681-8. [PMID: 10839654 DOI: 10.1089/jwh.1.1999.8.681] [Citation(s) in RCA: 138] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
More than 41,000 women aged 18-23, 45-50, and 70-75 years in 1996 are participating in the Australian Longitudinal Study on Women's Health (Women's Health Australia). Baseline surveys were conducted for all three cohorts in 1996, and the first follow-up survey of the mid-age group in 1998 has achieved a response rate exceeding 90%. The main findings so far reflect the large differences in the life experiences of the three cohorts. The young women report high levels of stress. The physical and mental health of those with young children is worse than for those without children, but confounding by sociodemographic characteristics may account for the differences. Two thirds of young women in the healthy weight or underweight range would like to weigh less, and early onset of dieting is associated with poorer physical and mental health. Most of the women in the mid-age group have multiple roles--in paid work, home duties, and caring for children and other dependents. The potential of the study to investigate the long-term impact of such busy lives on health outcomes is considerable. At this stage, the main health issues for these women relate to tiredness, weight gain, and menopause. The older cohort presents a picture of positive aging. These women are heavier users of health services than the mid-age and younger women, and they are also more satisfied with these services. Although their physical health is poorer, their mental health is better, and they report less stress than women in the other two cohorts. The follow-up survey of this group, planned for 1999, will focus on the coping strategies used by these women. An overall goal of the project is to understand the interactions among social roles, life events, and women's health in order to provide a basis for improved health policies and services. Analysis of these interactions, which relies on both quantitative and qualitative data, poses many challenges that will be addressed as the longitudinal data become available.
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de Figueiredo P, Polizotto RS, Drecktrah D, Brown WJ. Membrane tubule-mediated reassembly and maintenance of the Golgi complex is disrupted by phospholipase A2 antagonists. Mol Biol Cell 1999; 10:1763-82. [PMID: 10359595 PMCID: PMC25369 DOI: 10.1091/mbc.10.6.1763] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Although membrane tubules can be found extending from, and associated with, the Golgi complex of eukaryotic cells, their physiological function has remained unclear. To gain insight into the biological significance of membrane tubules, we have developed methods for selectively preventing their formation. We show here that a broad range of phospholipase A2 (PLA2) antagonists not only arrest membrane tubule-mediated events that occur late in the assembly of the Golgi complex but also perturb its normal steady-state tubulovesicular architecture by inducing a reversible fragmentation into separate "mini-stacks." In addition, we show that these same compounds prevent the formation of membrane tubules from Golgi stacks in an in vitro reconstitution system. This in vitro assay was further used to demonstrate that the relevant PLA2 activity originates from the cytoplasm. Taken together, these results demonstrate that Golgi membrane tubules, sensitive to potent and selective PLA2 antagonists, mediate both late events in the reassembly of the Golgi complex and the dynamic maintenance of its steady-state architecture. In addition, they implicate a role for cytoplasmic PLA2 enzymes in mediating these membrane trafficking events.
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Diebel LN, Liberati DM, Dulchavsky SA, Diglio CA, Brown WJ. Synergistic effect of hyperoxia and immunoglobulin A on mucosal barrier defense. THE JOURNAL OF TRAUMA 1999; 46:374-8; discussion 378-9. [PMID: 10088836 DOI: 10.1097/00005373-199903000-00004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Hyperoxia has been reported to be protective against gut-derived sepsis. Although secretory immunoglobulin A (IgA) is primarily responsible for humoral defense of mucosal surfaces, a potential synergistic effect with hyperoxia is unknown. An asanguineous cell monolayer system was used to study these aspects in vitro. METHODS MDCK cells were grown as polarized monolayers in a two-chamber culture system. Apical chambers were inoculated with 10(8) Escherichia coli M14 with or without polyclonal IgA and incubated in a 21 or 95% O2 environment. Basal medium was sampled at 90 and 180 minutes for bacterial translocation. In a second experiment, MDCK cells were lysed at 90 minutes and intracellular bacteria were quantitated. RESULTS Bacterial translocation was decreased versus normoxia by the treatment groups IgA without hyperoxia or IgA with hyperoxia at 90 minutes. Bacterial internalization at 90 minutes was reduced to the greatest extent by the combined effects of hyperoxia and IgA. Translocation data at 180 minutes confirmed the additional protective effect of hyperoxia with IgA. CONCLUSION Hyperoxia exerts a significant protective effect on barrier function independent of enhanced leukocyte function. Hyperoxia has an added effect to the mucosal defense provided by IgA.
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Brown WJ, Bryson L, Byles JE, Dobson AJ, Lee C, Mishra G, Schofield M. Women's Health Australia: recruitment for a national longitudinal cohort study. Women Health 1999; 28:23-40. [PMID: 10022055 DOI: 10.1300/j013v28n01_03] [Citation(s) in RCA: 441] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The Women's Health Australia (WHA) project is a longitudinal study of several cohorts of Australian women, which aims to examine the relationships between biological, psychological, social and lifestyle factors and women's physical health, emotional well-being, and their use of and satisfaction with health care. Using the Medicare database as a sampling frame (with oversampling of women from rural and remote areas), 106,000 women in the three age groups 18-23, 45-50 and 70-75 were sent an invitation to participate and a 24-page self-complete questionnaire. Reminder letters, a nation-wide publicity campaign, information brochures, a freecall number for inquiries, and the option of completing the questionnaire by telephone in English or in the respondent's own language, were used to encourage participation. Statutory regulations precluded telephone follow-up of non-respondents. Response rates were 41% (N = 14,792), 54% (N = 14,200) and 36% (N = 12,614) for the three age groups. Comparison with Australian census data indicated that the samples are reasonably representative of Australian women in these age groups, except for a somewhat higher representation of women who are married or in a defacto relationship, and of women with post-school education. The most common reason for non-participation was lack of interest or time. Personal circumstances, objections to the questionnaire or specific items in it, and concerns about confidentiality were the other main reasons. Recruitment of three representative age-group cohorts of women, and the maintenance of these cohorts over a number of years, will provide a valuable opportunity to examine associations over time between aspects of women's lives and their physical and emotional health and well-being.
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Hazelett SE, Liebelt RA, Brown WJ, Androulakakis V, Jarjoura D, Truitt EB. Evaluation of acetaldehyde-modified hemoglobin and other markers of chronic heavy alcohol use: effects of gender and hemoglobin concentration. Alcohol Clin Exp Res 1998; 22:1813-9. [PMID: 9835301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
The present study examined whether measurement of hemoglobin-acetaldehyde (HbA1-AcH) using an improved methodology may be useful as a biological marker of alcohol abuse. Red blood cell hemolysates of 182 patients consecutively admitted to the drug and alcohol treatment unit of our institution were analyzed for HbA1-AcH concentration using cation exchange HPLC. Mean HbA1-AcH of those who claimed to drink > or = 6 drinks/day [mean = 0.055 (% total hemoglobin), SD = 0.051] was significantly higher than the mean of those who drank < 6 drinks/day (mean = 0.026, SD = 0.0174). The greatest sum of sensitivity (67%) and specificity (77%) came with a cut-score of 0.030 area% of total hemoglobin. A cut-score of 0.080 produced a 100% specificity, but lowered the sensitivity to 20%. The Pearson product moment correlation (r) between HbA1-AcH and reported drinks per day was r = 0.30 (p < 0.001). There was no significant difference in the association of HbA1-AcH and reported drinking between males and females, and the small difference observed was shown to be entirely associated with differences in hemoglobin levels between the sexes. Cocaine use did not significantly alter the correlation between reported drinking and HbA1-AcH levels. Hemoglobin levels were shown to have a significant correlation with HbA1-AcH independent of drinking. HbA1-AcH was shown to have a better sensitivity and specificity than gamma-glutamyltransferase, ALT, AST, or mean corpuscular volume in this population. The results suggest that HbA1-AcH may be a useful marker to help detect alcohol abuse, especially in populations where other markers have been shown to fail.
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de Figueiredo P, Drecktrah D, Katzenellenbogen JA, Strang M, Brown WJ. Evidence that phospholipase A2 activity is required for Golgi complex and trans Golgi network membrane tubulation. Proc Natl Acad Sci U S A 1998; 95:8642-7. [PMID: 9671731 PMCID: PMC21129 DOI: 10.1073/pnas.95.15.8642] [Citation(s) in RCA: 122] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/1997] [Accepted: 05/27/1998] [Indexed: 02/08/2023] Open
Abstract
Membrane tubules of uniform diameter (60-80 nm) and various lengths (up to several micrometers) emanate from elements of the Golgi stack and trans Golgi network (TGN). These organelle membrane tubules are thought to be involved in membrane trafficking and maintenance of Golgi/TGN architecture. The number of these tubules, and their frequency of formation, can be greatly enhanced by the fungal metabolite brefeldin A (BFA), an inhibitor of Golgi/TGN-associated coated vesicle formation. We show here that BFA stimulation of Golgi and TGN membrane tubulation, and the resultant retrograde transport of resident Golgi enzymes to the endoplasmic reticulum, was potently inhibited by a number of membrane-permeant antagonists of phospholipase A2 (PLA2; EC 3.1.1.4) activity. In addition, PLA2 inhibitors on their own caused a reversible fragmentation of the Golgi complex into juxtanuclear, stacked cisternal elements. We conclude from these observations that tubulation of Golgi complex and TGN membranes requires a PLA2 activity, and that this activity may participate not only in Golgi tubule-mediated retrograde trafficking to the endoplasmic reticulum, but also in the maintenance of Golgi complex architecture.
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Abstract
OBJECTIVE To explore associations between body mass index (BMI) and selected indicators of health and well-being and to suggest a healthy weight range (based on BMI) for middle aged Australian women. DESIGN Population based longitudinal study (cross-sectional baseline data). SUBJECTS 13431 women aged 45-49 y who participated in the baseline survey for the Australian Longitudinal Study on Women's Health. RESULTS Forty-eight percent of women had a BMI>25 kg/m2. Prevalence of medical problems (for example, hypertension, diabetes), surgical procedures (cholescystectomy, hysterectomy) and symptoms (for example, back pain) increased monotonically with BMI, while indicators of health care use (for example, visits to doctors) showed a 'J' shaped relationship with BMI. Scores for several sub-scales of the MOS short form health survey (SF36) (for example, general health, role limitations due to emotional difficulties, social function, mental health and vitality) were optimal when BMI was around 19-24 kg/m2. After adjustment for area of residence, education, smoking, exercise and menopausal status, low BMI was associated with fewer physical health problems than mid-level or higher BMI, and the nationally recommended BMI range of 20-25 was associated with optimum mental health, lower prevalence of tiredness and lowest use of health services. CONCLUSIONS Acknowledging the limitations of the cross-sectional nature of these data, the results firmly support the benefits of leanness in terms of reducing the risk of cardiovascular disease, diabetes and gall bladder disease. The findings are moderated, however, by the observation that both low and high BMI are associated with decreased vitality and poorer mental health. The optimal range for BMI appears to be about 19-24 kg/m2. From a public health perspective this study provides strong support for the recommended BMI range of 20-25 as an appropriate target for the promotion of healthy weight in middle aged Australian women.
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Drecktrah D, de Figueiredo P, Mason RM, Brown WJ. Retrograde trafficking of both Golgi complex and TGN markers to the ER induced by nordihydroguaiaretic acid and cyclofenil diphenol. J Cell Sci 1998; 111 ( Pt 7):951-65. [PMID: 9490639 DOI: 10.1242/jcs.111.7.951] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Previous studies have shown that the Golgi stack and the trans-Golgi network (TGN) may play a role in capturing escaped resident endoplasmic reticulum (ER) proteins, and directing their retrograde transport back to that organelle. Whether this retrograde movement represents a highly specific or more generalized membrane trafficking pathway is unclear. To better understand both the retrograde and anterograde trafficking pathways of the secretory apparatus, we examined more closely the in vivo effects of two structurally unrelated compounds, the potent lipoxygenase inhibitor nordihydroguaiaretic acid (NDGA), and the non-steroidal estrogen cyclofenil diphenol (CFD), both of which are known to inhibit secretion. In the presence of these compounds, transport of vesicular stomatitis virus G membrane glycoprotein from the ER to the Golgi complex, and from the TGN to the cell surface, was inhibited potently and rapidly. Surprisingly, we found that NDGA and CFD stimulated the rapid, but not concomitant, retrograde movement of both Golgi stack and TGN membrane proteins back to the ER until both organelles were morphologically absent from cells. Both NDGA- and CFD-stimulated TGN and Golgi retrograde membrane trafficking were inhibited by microtubule depolymerizing agents and energy poisons. Removal of NDGA and CFD resulted in the complete, but not concomitant, reformation of both Golgi stacks and their closely associated TGN compartments. These studies suggest that NDGA and CFD unmask a generalized bulk recycling pathway to the ER for both Golgi and TGN membranes and, further, that NDGA and CFD are useful for investigating the molecular mechanisms that control the formation and maintenance of both the Golgi stack proper and the TGN.
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Diebel LN, Liberati DM, Brown WJ, Dulchavsky SA, Painter TM, Diglio CA, Montgomery PC. Secretory immunoglobulin A blocks hypoxia-augmented bacterial passage across Madin-Darby canine kidney cell monolayers. THE JOURNAL OF TRAUMA 1997; 43:759-63. [PMID: 9390486 DOI: 10.1097/00005373-199711000-00005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
OBJECTIVE To study the relative impact of previous hypoxic exposure and the addition of secretory immunoglobulin A (IgA) on bacterial translocation. DESIGN In vitro randomized experimental study. MATERIALS AND METHODS Transfected Madin-Darby canine kidney epithelial cells were grown as monolayers in a two-chamber tissue culture system. Stationary growth phase Escherichia coli M14 were inoculated in the apical chamber with medium or medium containing polymeric secretory IgA. Tissue culture dishes were then placed in a 21 or 5% O2 incubator environment for 90 minutes followed by a 21% O2 environment. Medium from the basal compartment was then obtained at timed intervals for bacterial culture. MEASUREMENT AND MAIN RESULTS Bacterial translocation increased with time in co-culture. Previous hypoxic exposure augmented translocation across the monolayers. The addition of IgA blocked translocation under both normoxic and hypoxic conditions. CONCLUSION Secretory IgA is important in mucosal defense under both normal and shock conditions.
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Diebel LN, Dulchavsky SA, Brown WJ. Splanchnic ischemia and bacterial translocation in the abdominal compartment syndrome. THE JOURNAL OF TRAUMA 1997; 43:852-5. [PMID: 9390500 DOI: 10.1097/00005373-199711000-00019] [Citation(s) in RCA: 151] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
BACKGROUND AND METHODS Major trauma or abdominal injury may lead to the development of increased intra-abdominal pressure (IAP) and the onset of the abdominal compartment syndrome. Although the effect of raised IAP on systemic and splanchnic hemodynamics have been described, the consequences of the resultant gut hypoperfusion in this setting are unknown. Bacterial translocation (BT) occurs after a period of splanchnic ischemia and may contribute to later organ failure. A rodent model was used to examine the effect of raised IAP on ileal mucosal blood flow (MBF) and BT. IAP was increased to 25 mm Hg for 60 minutes and mean arterial blood pressure was maintained with fluid. Animals were killed 24 hours later and examined for BT. RESULTS Increased IAP resulted in a decrease of MBF to 63% of baseline despite maintaining normal mean arterial blood pressure. BT occurred principally to the mesenteric lymph nodes after 60 minutes of IAP at 25 mm Hg. CONCLUSIONS Increased IAP leads to decreased MBF and to BT, which may contribute to later septic complications and organ failure.
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Brown WJ, Alexander J, McDonald B, Mills-Evers T. The health of Filipinas in the Hunter region. Aust N Z J Public Health 1997; 21:214-6. [PMID: 9161081 DOI: 10.1111/j.1467-842x.1997.tb01686.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
An interview survey found life-style behaviours (including risk factors and screening), social support and psychological health (GHQ-12) among a sample of 198 Filipina-Australians to be conducive to good health. Knowledge of local health services was good, and most women expressed general satisfaction with all aspects of life in Australia, except in the area of employment prospects. Despite these indications of good health in the group, there remains a need for health service providers to be aware of the difficulties faced by a proportion of Filipina migrants to Australia.
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Diebel LN, Raafat AM, Dulchavsky SA, Brown WJ. Gallbladder and biliary tract candidiasis. Surgery 1996; 120:760-4; discussion 764-5. [PMID: 8862389 DOI: 10.1016/s0039-6060(96)80028-6] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
BACKGROUND The clinical significance of Candida spp isolated from the gallbladder on the biliary tract is relatively unknown. METHODS To provide this information, patients with Candida spp isolated from gallbladder and other biliary tract sources during a 10-year period were identified through the records of our clinical microbiology laboratory. Medical records were analyzed for biliary disease causes, culture data, treatment, and outcome. RESULTS Twenty-seven patients were identified. Five of seven patients with cholecystitis were critically ill intensive care unit (ICU) patients in whom the mortality rate was 100%. Gallstone pancreatitis was found in four patients and was fatal in one patient with a pancreatic abscess and ongoing retroperitoneal sepsis. An external biliary shunt/endoprosthesis was placed in 16 patients to relieve biliary obstruction. Cholangitis was present in 14 patients, and most bile cultures contained Candida as part of a mixed flora. Only 3 of 27 patients had candidemia, and 22 of 27 patients were colonized with Candida at other sites. CONCLUSIONS (1) The ICU patient with Candida cholecystitis has a grave prognosis. (2) Patients with Candida isolated from biliary stents placed for obstruction and cholangitis should be treated with both antifungal and broad spectrum antimicrobial agents. (3) Candidemia is not frequently seen in this setting.
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Abstract
OBJECTIVE The main objective of this project was to evaluate a collaborative nurse and general practitioner approach to improve screening for cervical cancer. DESIGN Multiple group time series design. SETTING Six postal areas in the Hunter Valley of New South Wales, Australia, chosen as intervention sites because of very low Pap test rates compared with the rest of NSW (fewer than 50% of women screened). Six regions of similar size and with similar baseline screening levels were selected as comparison sites. SUBJECTS All women selected in the resident postal areas. INTERVENTIONS Women's health nurses worked in collaboration with general practitioners within the communities selected from within the Hunter area to promote and provide screening for cervical cancer. MAIN OUTCOME MEASURES Qualitative information on initial expectations and impressions of the collaborative processes were collected at the start of the project period. Process data on client characteristics and Pap test results were obtained from minimum data collections; client satisfaction was assessed from client surveys. Outcome data on the increase in the number of women in each community who were screened for cervical cancer were obtained from Health Insurance Commission claims for screening Pap tests (and from nurses' records where Pap tests were examined under block funding arrangements). RESULTS This project showed that nurses and general practitioners can collaborate to provide appropriate and highly acceptable cervical cancer screening services for women. Many of the women screened by the nurses were in the high risk age range for cervical cancer (40 years and older) and had only basic education levels, thus representing women who are most likely to have poor screening rates. Further, 33.1% of the women screened had not had a Pap test in the past four years or had never been screened. The number of women having a Pap test during the first six months of the project, compared with the number expected from preintervention patterns, was significantly greater in four intervention areas (P < 0.01). No corresponding increase was seen in comparison areas with similar screening rates at baseline. CONCLUSIONS There is great potential for nurses to work in collaboration with general practitioners to improve the availability and coverage of community cervical cancer screening programmes.
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Brown WJ, Doran FM. Women's health: consumer views for planning local health promotion and health care priorities. Aust N Z J Public Health 1996; 20:149-54. [PMID: 8799089 DOI: 10.1111/j.1753-6405.1996.tb01809.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
A random door knock survey was conducted in five metropolitan postcode areas with a high proportion of low-income households to establish: 1. the health problems experienced by women, 2. the problems with which women would have liked more help, and 3. women's perceptions of how their health care experiences might have been improved. In all, 214 women were interviewed. Across all age groups the most common problems were tiredness, premenstrual syndrome, stress, being overweight and disturbed sleep. Premenstrual syndrome, tiredness and arthritis were the most commonly experienced problems among younger, middle-aged and older women respectively. In general, women were satisfied with the help available to them for their health problems, but one in five would have liked more help to cope with stress, and one in six said they would like help to address the issue of quality of medical care. In relation to health care services, suggestions for improvement included the provision of better health information from doctors and other health care professionals, and more opportunities for counselling and self-help. The project findings will be used to influence the development of local policies and services, and will form the focus for local women's health promotion programs.
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Banta M, Polizotto RS, Wood SA, de Figueiredo P, Brown WJ. Characterization of a cytosolic activity that induces the formation of Golgi membrane tubules in a cell-free reconstitution system. Biochemistry 1995; 34:13359-66. [PMID: 7577921 DOI: 10.1021/bi00041a012] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Using a cell-free reconstitution system, we have characterized a cytosol- and ATP-dependent process that leads to the formation of membrane tubules from isolated Golgi complexes. These membrane tubules are uniform in diameter (50-70 nm) and morphologically identical to ones normally seen in cells and to those which are enhanced following brefeldin A treatment. Tubulation was strictly dependent on an activity present in an organelle-free extract of bovine brain cytosol and hydrolyzable ATP. Tubule formation was saturable with respect to both cytosol and ATP with half-maximal induction occurring at approximately 0.5 mg/mL cytosol and 10-20 microM ATP. Mild proteolytic treatment of Golgi membranes significantly reduced the extent of tubulation to subsequently added cytosol, suggesting that the tubulation activity interacts with Golgi-associated membrane proteins. The cytosolic tubulation activity was heat-labile, nondialyzable, and precipitated in ammonium sulfate. This activity could be followed through various chromatographic steps to yield fractions enriched in a major 40 kDa protein and several other minor proteins of approximately 80, 60, and 30 kDa. Monospecific antibodies against the 40K protein inhibited the cytosol-dependent tubulation of Golgi membranes in the cell-free system. Gel filtration chromatography suggests that the tubulation activity has a native molecular weight of approximately 125,000-140,000. These results establish the existence of cytosolic protein factors that regulate the formation of Golgi membrane tubules, and will provide the means for a biochemical dissection of membrane tubulation.
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Brown WJ, DeWald DB, Emr SD, Plutner H, Balch WE. Role for phosphatidylinositol 3-kinase in the sorting and transport of newly synthesized lysosomal enzymes in mammalian cells. J Cell Biol 1995; 130:781-96. [PMID: 7642697 PMCID: PMC2199950 DOI: 10.1083/jcb.130.4.781] [Citation(s) in RCA: 228] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Previous work with the yeast Saccharomyces cerevisiae has demonstrated a role for a phosphatidylinositol-specific PI 3-kinase, the product of the VPS34 gene, in the targeting of newly synthesized proteins to the vacuole, an organelle functionally equivalent to mammalian lysosomes (Schu, P. V., K. Takegawa, M. J. Fry, J. H. Stack, M. D. Waterfield, and S. D. Emr. 1993. Science [Wash. DC]. 260:88-91). The activity of Vps34p kinase is significantly reduced by the PI 3-kinase inhibitors wortmannin, a fungal metabolite, and LY294002, a quercetin analog (Stack, J. H., and S. D. Emr. 1994. J. Biol. Chem. 269:31552-31562). We show here that at concentrations which inhibit VPS34-encoded PI 3-kinase activity, wortmannin also inhibits the processing and delivery of newly synthesized cathepsin D to lysosomes in mammalian cells with half-maximal inhibition of delivery occurring at 100 nM wortmannin. As a result of wortmannin action, newly synthesized, unprocessed cathepsin D is secreted into the media. Moreover, after accumulation in the trans-Golgi network (TGN) at 20 degrees C, cathepsin D was rapidly missorted to the secretory pathway after addition of wortmannin and shifting to 37 degrees C. At concentrations that inhibited lysosomal enzyme delivery, both wortmannin and LY294002 caused a highly specific dilation of mannose 6-phosphate receptor (M6PR)-enriched vesicles of the prelysosome compartment (PLC), which swelled to approximately 1 micron within 15 min after treatment. With increasing time, the inhibitors caused a significant yet reversible change in M6PR distribution. By 3 h of treatment, the swollen PLC vacuoles were essentially depleted of receptors and, in addition, there was a fourfold loss of receptors from the cell surface. However, M6PRs were still abundant in the TGN. These results are most consistent with the interpretation that PI 3-kinase regulates the trafficking of lysosomal enzymes by interfering with a M6PR-dependent sorting event in the TGN. Moreover, they provide evidence that trafficking of soluble hydrolases to mammalian lysosomes and yeast vacuoles rely on similar regulatory mechanisms.
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Abstract
Membrane tubules of uniform diameter (60-80 nm) and variable lengths have been seen to extend from the main bodies of the Golgi complex, trans Golgi network (TGN), and endosomes. In the case of endosomes, these tubules appear to mediate membrane and receptor recycling events. Brefeldin A (BFA) is a potent drug that completely blocks coated vesicle formation from the Golgi complex and TGN, but at the same time causes the enhanced formation of membrane tubules from these same organelles. Recently, experiments have shown that calmodulin antagonists inhibit the transport of receptors out of endosomes, perhaps by inhibiting the formation of recycling tubules. Using the potent calmodulin-specific antagonists N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide (W-7), N-(4-aminobutyl)-5-chloro-2-naphthalenesulfonamide (W-13), and N-(4-aminobutyl)-5-chloro-1-naphthalenesulfonamide (C-1), we found that the recycling of transferrin from endosomes to the cell surface was significantly inhibited, resulting in the formation of enlarged endosomal vacuoles. In addition, these same calmodulin antagonists also potently inhibited the formation of BFA-stimulated membrane tubules from the Golgi complex, TGN, and endosomes. In the case of the Golgi complex, failure to form tubules resulted in the inhibition of BFA-stimulated retrograde transport to the endoplasmic reticulum. These results suggest that calmodulin is a general regulator of membrane tubulation and is capable of influencing the morphology of several organelles.
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Marik PE, Brown WJ. A comparison of bronchoscopic vs blind protected specimen brush sampling in patients with suspected ventilator-associated pneumonia. Chest 1995; 108:203-7. [PMID: 7606959 DOI: 10.1378/chest.108.1.203] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
BACKGROUND Pneumonia is a common complication in patients undergoing mechanical ventilation and increases ICU mortality. The clinical diagnosis of ventilator-associated, however, pneumonia is unreliable, and many consider bronchoscopic-directed protected specimen brush sampling and quantitative culture the diagnostic method of choice. Bronchoscopy, however, is expensive and not readily available in many ICUs. OBJECTIVE To test the hypothesis that "blind" protected specimen brush (PSB) sampling may produce results similar to that of bronchoscopic-directed sampling. SETTING The medical ICU of a university-affiliated teaching hospital. INTERVENTION Patients with suspected ventilator-associated pneumonia (VAP) who had not received antibiotics for at least 48 h underwent "blind" and bronchoscopic-directed PSB sampling with quantitative culture. RESULTS Fifty-five paired PSB specimens were obtained from 53 patients. There was an 85% quantitative agreement between the blind and bronchoscopic-directed specimens. The agreement was independent of the bronchopulmonary segment from which the bronchoscopic sampling was directed. CONCLUSION The results of this study are consistent with the notion that blind PSB sampling and quantitative culture may prove to be a useful, cost-effective, and minimally invasive method of diagnosing VAP.
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141
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Brown WJ, Redman S. Setting targets: a three-stage model for determining priorities for health promotion. AUSTRALIAN JOURNAL OF PUBLIC HEALTH 1995; 19:263-9. [PMID: 7626677 DOI: 10.1111/j.1753-6405.1995.tb00441.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
This paper describes a three-stage model for setting targets for health promotion. The model was developed in 1992 in response to the need to identify priority areas for health promotion for women in the Hunter Region of New South Wales. The approach enabled epidemiological data and views from the community to be synthesised and integrated with those of experts from health and social services (key informants), using a nominal group process. The reliability of the method was investigated by replicating the process with two groups of key informants. There was considerable commonality in the targets generated by the two groups. The process resulted in the identification of seven targets that reflected the concerns of the community and local experts as well as the health priorities suggested by local epidemiological data. The model used could be adapted for determining priorities in a wide range of health and health care settings, where available resources restrict the range of services or activities which can be offered.
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Singelis TM, Brown WJ. Culture, self, and collectivist communication: linking culture to individual behavior. HUMAN COMMUNICATION RESEARCH 1995; 21:354-389. [PMID: 12349710 DOI: 10.1111/j.1468-2958.1995.tb00351.x] [Citation(s) in RCA: 93] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
This study develops and demonstrates a theoretical framework and corresponding methodology to link variables at the culture level to the individual level and, then, to specific outcome variables. The authors argue that in order to advance theory about culture's influence on communication, researchers must begin to examine how culture affects individual level (psychological) processes and, subsequently, how these processes affect communication. The image of self, referred to as self-construal, is an ideal candidate to perform the role of linking culture to behavior. The self is shaped by cultural forces and affects many, if not all, communication behaviors. The proposed strategy is applied in the test of a path-analytic model linking cultural collectivism with interdependent self-construals and, ultimately, high-context communication. The discussion includes implications for theory development and possible applications to further research.
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143
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Ruge A, Lee C, Brown WJ. Inpatient cervical screening: a survey of patient acceptability. AUSTRALIAN JOURNAL OF PUBLIC HEALTH 1995; 19:96-7. [PMID: 7734605 DOI: 10.1111/j.1753-6405.1995.tb00306.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Offering Pap tests to hospital inpatients could increase cervical screening rates. A survey to examine the acceptability of this concept was conducted with female inpatients in a rural public hospital. A large majority reported that they would find hospital Pap tests acceptable. Acceptability was not related to Pap test status, attitudes, or knowledge of cervical cancer. This strategy may provide access to cervical screening for underscreened groups.
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Brown WJ. The birth of an employee safety committee. EXECUTIVE HOUSEKEEPING TODAY 1994; 15:9. [PMID: 10139134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
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145
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Brown WJ, Lee C. Exercise and dietary modification with women of non-english speaking background: A pilot study with polish-australian women. Int J Behav Med 1994; 1:185-203. [PMID: 16250796 DOI: 10.1207/s15327558ijbm0103_1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
Health promotion programs aimed at the general community often fail to reach Australians of non-English speaking background (NESB) because of language and cultural barriers. A 12-week minimal-intervention heart health program, designed for women of European background, was piloted with 43 women from a Polish social group, with a further 30 women serving as a comparison group. Assessments of the intervention group before and after the 12-week program indicated significant decreases in exercising heart rate and in resting blood pressure, which were not evident in the comparison group. Twelve-week follow-up data indicated that these gains had been well maintained. When the comparison group was invited to participate in a similar program, there were also significant improvements on these variables. This pilot study suggests that health promotion programs aimed at NESB Australians can be effective in modifying risk factors for cardiovascular disease if an effort is made lo address language and cultural barriers.
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Brown WJ. Microbiology of the infected total joint arthroplasty. SEMINARS IN ARTHROPLASTY 1994; 5:107-13. [PMID: 10155152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
Infection associated with arthroplasty is a relatively rare event, but when it does occur, it is of major consequence for the patient. Many organisms can cause these infections, but most are the results of gram-positive bacteria, with the genus Staphylococcus accounting for at least 50%. Streptococcus and aerobic gram-negative bacilli are responsible for another significant percentage. The ability of the organism to produce a slime or glycocalix extracellular layer seems to be a contributing virulence factor for prosthesis-associated infections. Growth, identification, and susceptibility testing of the etiologic agent are performed by the microbiology laboratory, but antimicrobial treatment is usually only successful after removal of the prosthesis.
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Dyke JW, Brown WJ, Morris JM, Pierson CL, Peters EM. Evaluation of the new DrySlide beta-lactamase test. Am J Clin Pathol 1994; 101:726-8. [PMID: 8209859 DOI: 10.1093/ajcp/101.6.726] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Four hundred thirteen recent clinical isolates of Staphylococcus, Haemophilus, Moraxella, and Neisseria species were tested for beta-lactamase production using the Difco DrySlide beta-lactamase test. These results were compared with those of the BBL Cefinase reagent. Of the 413 isolates tested, 258 (62.5%) were beta-lactamase positive. There was 99.8% agreement between the two test methods; only one isolate of Staphylococcus aureus was DrySlide-negative and Cefinase-positive. The DrySlide beta-lactamase reagent is an accurate and convenient format for the evaluation of beta-lactamase activity in the clinical laboratory.
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Lynch WP, Brown WJ, Spangrude GJ, Portis JL. Microglial infection by a neurovirulent murine retrovirus results in defective processing of envelope protein and intracellular budding of virus particles. J Virol 1994; 68:3401-9. [PMID: 8151801 PMCID: PMC236834 DOI: 10.1128/jvi.68.5.3401-3409.1994] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
The observation of murine retrovirus infection of microglial cells in brain regions expressing spongiform neurodegenerative changes suggests that these cells may play an important role in pathogenesis. To evaluate this potential in vitro, murine microglial cells were infected in mixed glial cultures with the highly neurovirulent murine retrovirus, FrCasE. The microglia were then isolated from the mixed cultures on the basis of their differential adherence and shown to be approximately 98% pure. The infected microglia expressed viral envelope protein at the plasma membrane, while viral budding was primarily intracellular. Evaluation of the viral envelope protein by immunoblotting indicated that the immunoreactive species produced was exclusively a 90-kDa precursor protein. Very little of the envelope protein was associated with particles released from these cells, and viral titers in the culture supernatant were low. Interestingly, these cells were still capable of infecting permissive target cells when seeded as infectious centers. This partially defective infection of microglial cells suggests a potential cellular means by which a neurovirulent retrovirus could disrupt normal microglia and in turn central nervous system motor system functioning.
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Chandrasekar PH, Brown WJ. Clinical issues of blood cultures. ARCHIVES OF INTERNAL MEDICINE 1994; 154:841-9. [PMID: 8154947] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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Heller L, Park JE, Brown WJ. Biosynthesis and intracellular transport of a membrane glycoprotein (plgp57) of the prelysosome compartment. Mol Membr Biol 1994; 11:127-34. [PMID: 7920865 DOI: 10.3109/09687689409162230] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
We have characterized the biosynthesis and intracellular transport of a membrane glycoprotein, designated plgp57, which is found predominantly in the prelysosome compartment (PLC) of Madin-Darby bovine kidney cells. In pulse-chase experiments, plgp57 was found to be initially synthesized as a 35 kDa precursor which was modified to yield a diffuse approximately 57 kDa mature form. Digestion with endoglycosidase H (endo H) demonstrated that the 35 kDa precursor contained three endo H-sensitive, high mannose-type oligosaccharides which became modified to endo H-resistant, complex-type sugars on the approximately 57 kDa mature form. Labelling cells in the presence of tunicamycin and treatment of the 35 kDa precursor with endo H revealed that plgp57 has a core protein of 24 kDa to which three N-asparagine-liked oligosaccharides are attached. Other experiments indicated that plgp57 could be differentially glycosylated on a common 24 kDa core protein in different cell types. The half-lives of the glycosylated and non-glycosylated forms of plgp57 were approximately 18 and approximately 13 h, respectively. Glycosylated and non-glycosylated plgp57 exhibited similar steady-state intracellular distributions, indicating that targeting of plgp57 to the PLC does not require carbohydrate address markers. Pulse-labeling of cells followed by organelle fractionation at various chase times revealed a t1/2 = approximately 1 h for the transit of newly synthesized plgp57 to the PLC. Finally, amino terminal sequencing of plgp57 revealed the similarity of this protein to the CD63/ME491 family of membrane glycoproteins.
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