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Biomedical subjects

G Bailey

Publications and source records attributed to G Bailey.

At least 19 recordsLinked to original sources
PubMed2004

An evaluation of differences in hip external rotation strength and range of motion between female dancers and non-dancers.

OBJECTIVES: To evaluate the differences in hip external rotation (ER) strength and inner, outer, and total hip ER range of motion (ROM) between dancers and non-dancers and between left and right sides in each group. METHODS: Seventy one subjects (34 dancers and 37 non-dancers) volunteered for this study. The strength (truncated range average torque (TRAT), work, and angle specific torque (AST)) of the hip external rotator muscle group, through the full available active hip ER ROM, was evaluated using concentric isokinetic (30 degrees /s) testing on a KinCom dynamometer. Adjustment for lean body mass (LBM) was made for comparison of strength between groups. A two way repeated analysis of covariance was used to compare strength between groups. A two way repeated analysis of variance was used to compare strength between sides and ROM between groups and sides. Bonferroni correction was made for multiple analyses, and significance was accepted at p<or=0.05. RESULTS: AST at 0 degrees , 20 degrees , 30 degrees , and 40 degrees of hip ER was greater in the dancers than the non-dancers (p<or=0.022). TRAT, work, AST(0 degrees ), AST(20 degrees ), and AST(30 degrees ) of hip ER were all greater on the right side than the left (p = 0.007) in both groups. Dancers had greater inner ER ROM (p = 0.013) and less outer ER ROM than non-dancers (p<or=0.001). There was no difference in total ER ROM between groups (p = 0.133). The right side had greater inner ER (p<or=0.001) and total ER ROM (p<or=0.001) than the left in both groups. CONCLUSIONS: Ballet dancers have greater inner range, angle specific strength and inner range ER ROM, demonstrated by a shift in the dancers' strength curves. This shift in the strength curve towards the inner range of hip ER may be an adaptive training response.

Adolescent↗
PubMed2002

Immunohistochemical characterization of lymphosarcoma in two alpacas (Lama pacos).

Species cross-reactive anti-peptide antibodies were assessed in formalin-fixed tissue for use in immunophenotyping of lymphosarcoma in two alpacas. Diagnosis of lymphosarcoma was made by routine histopathological examination. Primary antibodies used for immunophenotyping were anti-human CD3 and anti-human CD5 for T cells; and anti-human CD79a and anti-human CD79b for B cells/plasma cells. In one case, most of the neoplastic cells were labelled with both anti-CD3 and anti-CD79b, and smaller numbers were labelled with anti-CD79a. The other case was classified as a B-cell tumour on the basis of labelling of the majority of neoplastic cells with anti-CD79b and anti-CD79a. This is the first recorded attempt at immunophenotyping lymphosarcoma in alpacas and, to our knowledge, the first record of presumptive co-expression of T- and B-cell-associated molecules in lymphosarcoma in the veterinary literature.

Animals↗
PubMed2001

Virulence properties and serotypes of Shiga toxin-producing Escherichia coli from healthy Australian slaughter-age sheep.

A group of 1,623 ovine fecal samples recovered from 65 geographically distinct mutton sheep and prime lamb properties across New South Wales, Australia, were screened for the presence of Shiga toxin-producing Escherichia coli (STEC) virulence factors (stx(1), stx(2), eaeA, and ehxA). A subset was cultured for STEC isolates containing associated virulence factors (eaeA and/or ehxA), which were isolated from 17 of 20 (85%) and 19 of 20 (95%) tested prime lamb and mutton sheep properties, respectively. STEC isolates containing stx(1), stx(2), and ehxA were most commonly isolated (19 of 40 flocks; 47.5%), and this profile was observed for 10 different serotypes. Among 90 STEC isolates studied, the most common serotypes were O91:H(-) (22 isolates [24.4%]), O5:H(-) (16 isolates [17.8%]), O128:H2 (11 isolates [12.2%]), O123:H(-) (8 isolates [8.9%]), and O85:H49 (5 isolates [5.6%]). Two isolates (2.2%) were typed as O157:H(-). A total of 78 of 90 STEC isolates (86.7%) expressed Shiga toxin in Vero cell culture and 75 of 84 ehxA-positive isolates (89.3%) expressed enterohemolysin on washed sheep blood agar. eaeA was observed in 11 of 90 (12.2%) ovine STEC isolates, including serotypes O5:H(-), O84:H(-), O85:H49, O123:H(-) O136:H40, and O157:H(-). Although only 2 of 90 isolates were typed as O157:H(-), the predominant serotypes recovered during this study have been recovered from human patients with clinical disease, albeit rarely.

Abattoirs↗
PubMed2001

Staff rostering in the operating department.

The smooth running of the operating department is often facilitated by the goodwill of the staff who agree to stay behind when cases overrun, or work through lunch and coffee breaks. Many perioperative staff also cover on-calls and stand-bys, causing disruption to their social and family lives. These demands may make working in the operating department harder for some staff. With reference to current shortages of perioperative staff and staff retention, Judith Tanner and Gloria Bailey discuss some suggestions for being flexible with the off duty rota which may give staff more control and more choices over when they work.

Humans↗
PubMed2000

A comparison of thermocouple and infrared thermographic analysis of temperature rise on the root surface during the continuous wave of condensation technique.

AIM: This study was designed to use two methods of temperature measurement to analyse and quantify the in vitro root surface temperature changes during the initial stage of the continuous wave technique of obturation of 17 single-rooted premolar teeth with standard canal preparations. METHODOLOGY: A model was designed to allow simultaneous temperature measurement with both thermocouples and an infrared thermal imaging system. Two thermocouples were placed on the root surface, one coronally and the other near the root apex. A series of thermal images were recorded by an infrared thermal imaging camera during the downpack procedure. RESULTS: The mean temperature rises on the root surface, as measured by the two thermocouples, averaged 13.9 degrees C over the period of study, whilst the infrared thermal imaging system measured an average rise of 28.4 degrees C at the same sites. Temperatures at the more apical point were higher than those measured coronally. After the first wave of condensation, the second activation of the plugger in the canal prior to its removal always resulted in a secondary rise in temperature. The thermal imaging system detected areas of greater temperature change distant from the two selected thermocouple sites. CONCLUSIONS: The continuous wave technique of obturation may result in high temperatures on the external root surface. Infrared thermography is a useful device for mapping patterns of temperature change over a large area.

Adult↗
PubMed2000

Influence of beta-naphthoflavone on 7,12-dimethylbenz(a)anthracene metabolism, DNA adduction, and tumorigenicity in rainbow trout.

Metabolism, DNA adduction, and tumor induction by 7, 12-dimethylbenz(a)anthracene (DMBA) were examined in cultured trout liver cells and in vivo in trout. Modulating CYP1A1 activity indicated this enzyme plays a significant role in metabolizing DMBA to water-soluble compounds in isolated trout liver cells. The major DMBA metabolites identified in trout liver cells were 10-, 11-, 8,9-, and 5,6-DMBA dihydrodiols, and DMBA, 2- or 3- or 4-phenol; 7-OH-methyl-12-methyl-benz(a)anthracene and 12-OH-methyl-7-methyl-benz(a)anthracene were minor metabolites. A very small amount of DMBA-3,4-dihydrodiol was detected, and polar metabolites, which did not migrate with any DMBA metabolite standards, were observed. Incubating trout hepatocytes with DMBA-3, 4-dihydrodiol produced three prominent, nonpolar adducts indistinguishable from those in mouse embryo cells. However, DMBA-DNA adducts, formed in trout in vivo or in trout liver cells exposed to DMBA, were predominantly more polar than those formed in mouse embryo fibroblasts, and levels of DMBA-DNA adducts formed in trout liver cells were not significantly altered by modulating CYP1A1 activity. No significant repair of DMBA-DNA adducts was detected in cultured trout liver cells over a 48-h period, supporting previous studies indicating that fish are less efficient than mammals in repairing polyaromatic hydrocarbon DNA adducts. Compared to animals receiving DMBA alone, beta-naphthoflavone pretreatment in vivo did not affect hepatic CYP1A1, DMBA-DNA adducts, nor hepatic tumor response; but did significantly reduce tumor response in two other target organs. These results collectively indicate that DMBA bioactivation to DNA-binding metabolites in trout liver cells and mouse embryo cells predominantly involve different metabolic pathways to form the DNA-binding intermediates.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1999

The Mechanism of Lung Volume Change during Mechanical Ventilation.

To understand ventilator-induced lung injury (VILI) during positive pressure ventilation, mechanisms of normal alveolar mechanics must first be established. Isotropic "balloonlike" alveolar volume (VA) change has been viewed as the prevailing mechanism of normal lung volume (VL) changes. We hypothesized that change in VL is predominantly caused by alveolar recruitment-derecruitment (R/D). Fifteen mongrel dogs were anesthetized and intubated with a tracheal divider. Through a thoracotomy incision, in vivo microscopy of subpleural alveoli was performed as the degassed lung was inflated to 80% TLC, and then deflated to residual volume (RV). Still photomicrographs were evaluated to determine if change in VL is due to change in VA or R/D of alveoli. We noted a steady, significant increase in alveolar recruitment as VL increased to 80% TLC (p < 0.05). However, VA increased significantly, but only to 20% TLC (p < 0.05). Once recruited, alveoli did not demonstrate any further volume change, whereas the lung as a whole maintained a normal pressure/volume relationship. In our model, changes in VL predominantly are caused by R/D. Carney DE, Bredenberg CE, Schiller HJ, Picone AL, McCann UG II, Gatto LA, Bailey G, Fillinger M, Nieman GF. The mechanism of lung volume change during mechanical ventilation.

Journal Article↗
PubMed1999

Mechanisms of chlorophyllin anticarcinogenesis: dose-responsive inhibition of aflatoxin uptake and biodistribution following oral co-administration in rainbow trout.

Chlorophyllin (CHL) is a potent blocking agent against aflatoxin B(1) DNA adduction and tumorigenesis in the trout model, but mechanisms responsible for this chemoprotection in vivo are not well established. This study employed aflatoxin B(2) (AFB(2)), a structural analogue of AFB(1) that cannot be metabolized directly to the 8,9-exo-epoxide electrophile, to investigate CHL effects on carcinogen uptake and distribution kinetics following oral exposure in trout. CHL was shown to form an AFB(2) complex in vitro with a dissociation constant (K(d) = 1.92 +/- 0.13 microM) comparable to that with AFB(1). Following gavage, [(3)H]AFB(2) equivalents distributed rapidly from the stomach to other organs including blood, liver, and eventually to bile as a major repository. Bile was found to contain almost entirely parent AFB(2) 1 h after gavage, with a single metabolite dominating 3-24 h and an additional metabolite prominent by 48 h after gavage. Addition of sufficient CHL (>/=13.9 mM) to assure >99% complexation of AFB(2) (0.906 microM) in the gavage mix resulted in 80-90% reduction in AFB(2) equivalents in liver and bile 3 h after gavage. In three separate kinetic studies of up to 120 h postgavage, addition of >/=13.9 mM CHL to the gavage mix reproducibly and markedly delayed the rate of AFB(2) loss from stomach, retarded its appearance in blood, liver, and bile, and reduced peak AFB(2) concentrations in those tissues by up to 60%. Introduction of a food bolus immediately after gavage prolonged AFB(2) residence in stomach and intestine but did not abrogate the inhibitory effects of CHL on AFB(2) uptake and distribution. These results demonstrate that oral co-treatment with CHL under conditions where complex formation is initially assured, substantially reduces AFB(2) systemic uptake and target organ bioavailability in the trout.

Aflatoxins↗
PubMed1999

Chlorophyllin chemoprevention in trout initiated by aflatoxin B(1) bath treatment: An evaluation of reduced bioavailability vs. target organ protective mechanisms.

Chlorophyllin (CHL) is known to inhibit DNA adduction and hepatocarcinogenesis in trout when administered at doses up to 4000 ppm in the diet with aflatoxin B(1) (AFB(1)). The principal protective mechanism is believed to involve CHL:AFB(1) complex formation, which may reduce systemic carcinogen absorption. However, mechanisms operative within the target organ in situ have not been ruled out. The present study used alternative CHL and AFB(1) exposures as well as hepatic metabolism studies to distinguish these mechanisms. Duplicate lots of 150 rainbow trout each were initiated by brief water bath exposure to 0.1 ppm AFB(1), with or without 500 ppm CHL in the water. The addition of 500 ppm CHL to the water bath, under conditions where AFB(1) is calculated to be >99% sequestered as the CHL:AFB(1) complex, reduced hepatic AFB(1)-DNA adduction by 95% and reduced hepatocarcinogenesis from 20.5% to 2%, compared with exposure to AFB(1) alone. Inclusion of 500 ppm CHL in the water bath also significantly reduced total body burden and hepatic levels of AFB(1) as well as AFB(2), a structural analogue of AFB(1) unable to directly form the 8,9-epoxide proximate electrophile but equally capable of complexing with CHL. By contrast, internal target organ CHL loading by pretreatment of trout with 4000 ppm dietary CHL for 7 days prior to (and 2 days following) AFB(1) waterbath exposure had no effect on AFB(1)-DNA adduction or tumorigenicity. Dietary CHL up to 8000 ppm had no effect on hepatic CYP2K1, CYP1A, glutathione transferase, UDP-glucuronosyl transferase, or, with one exception, the relative ratios among hepatic AFB(1) metabolites in vivo. These results support the hypothesis that CHL:AFB(1) complex formation and reduced systemic AFB(1) bioavailability is a principal mechanism for CHL chemoprevention in this model and that in situ target organ inhibitory mechanisms are relatively insignificant.

Aflatoxin B1↗
PubMed1999

Mass mailing and staff experience in a total recruitment program for a clinical trial: the SHEP experience. Systolic Hypertension in the Elderly Program. Cooperative Research Group.

The Systolic Hypertension in the Elderly Program (SHEP) staff contacted 447,921 screenees, of whom 11,919 (2.7%) were originally eligible and 4,736 (1.1%) maintained eligibility and were randomized. The total number of participants enrolled at the 16 clinical centers ranged from 133 to 559. The low yield of screenees to randomizations resulted from the study design, not from low levels of agreement to participate, and required the employment of a variety of recruitment strategies in a prudent overall plan. SHEP was one of the first clinical trials to use mass mailing as a primary strategy of recruitment. The study used mailing lists from seven generic sources. More than 3.4 million letters of invitation were mailed; they yielded an overall response rate of 4.3%. Motor vehicle and voter registration lists provided the greatest numbers of names. Mailings to members of health maintenance organizations (HMOs) and registrants of the Health Care Finance Administration (HCFA) provided the greatest response rates. Considerable variability in response rates existed among clinical centers using generically similar mailing lists. Generally, the number of hours spent on recruitment showed a positive, but not statistically significant, association with randomization yields. The recruitment yield was statistically significantly higher in clinics with experienced recruitment coordinators than in clinics with inexperienced ones (p = 0.0008). From these findings we conclude that mass mailing is an important strategy in an overall recruitment program, that the involvement of experienced recruitment staff is important, and that although the total time spent by staff on recruitment may also improve results, it matters less than the staff's level of recruiting experience.

Aged↗
PubMed1999

The mechanism of lung volume change during mechanical ventilation.

To understand ventilator-induced lung injury (VILI) during positive pressure ventilation, mechanisms of normal alveolar mechanics must first be established. Isotropic "balloonlike" alveolar volume (VA) change has been viewed as the prevailing mechanism of normal lung volume (VL) changes. We hypothesized that change in VL is predominantly caused by alveolar recruitment-derecruitment (R/D). Fifteen mongrel dogs were anesthetized and intubated with a tracheal divider. Through a thoracotomy incision, in vivo microscopy of subpleural alveoli was performed as the degassed lung was inflated to 80% TLC, and then deflated to residual volume (RV). Still photomicrographs were evaluated to determine if change in VL is due to change in VA or R/D of alveoli. We noted a steady, significant increase in alveolar recruitment as VL increased to 80% TLC (p < 0.05). However, VA increased significantly, but only to 20% TLC (p < 0.05). Once recruited, alveoli did not demonstrate any further volume change, whereas the lung as a whole maintained a normal pressure/volume relationship. In our model, changes in VL predominantly are caused by R/D.

Airway Resistance↗
PubMed1998

Chemopreventive properties of chlorophylls towards aflatoxin B1: a review of the antimutagenicity and anticarcinogenicity data in rainbow trout.

The anticarcinogenic activity of chlorophyllin (CHL), a water-soluble derivative of chlorophyll, was first reported in rainbow trout. This review describes certain experiments which set the stage for long-term tumor bioassays, in trout and other species, using CHL and various food-borne carcinogens. Initial work with trout and rat liver enzymes in the Salmonella assay showed that CHL was a potent antimutagen towards heterocyclic amines, polycyclic aromatic hydrocarbons, aflatoxins and other classes of mutagen. Antimutagenic activity was further demonstrated using the corresponding direct-acting mutagens in the absence of an exogenous metabolizing system. Mutagen-inhibitor interaction (molecular complex formation) was identified in spectrophotometry studies, suggesting that CHL acts as an 'interceptor molecule'. In vivo, CHL reduced hepatic AFB1-DNA adducts and hepatocarcinogenesis when the inhibitor and carcinogen were co-administered in the diet. Finally, co-injection of inhibitor and AFB1 into trout embryos established that CHL was more effective than chlorophyll a in reducing AFB1-DNA adducts 2 weeks after injection, and liver tumors after 1 year.

Aflatoxin B1↗
PubMed1997

Current trends in HIV-related hospital admissions and their impact on hospital resource utilization in Ontario.

OBJECTIVE: To assess changes in patterns of hospital admissions, in frequency of admissions and in average length of stay (ALOS) at a tertiary HIV referral centre, and to investigate the overall impact of care for patients with HIV infection of AIDS on peer hospitals in Ontario. DESIGN: Descriptive study. PARTICIPANTS: Data were obtained on patients with HIV infection or AIDS treated at the Wellesley Hospital in Toronto for the fiscal years (May 1 to Apr. 31) 1990-91, 1991-92 and 1992-93, and on admissions for HIV or AIDS in 9 peer hospitals in Ontario during the same period. INTERVENTIONS: For the Wellesley Hospital, review of medical records of HIV-related admissions to determine the reasons for admission and to examine concurrent illnesses. For the Wellesley Hospital Hospital and peer hospitals, analysis of changes in ALOS and Resource Intensity Weights (RIWs). RESULTS: Between May 1, 1990, and Apr. 31, 1993, the number of admissions for treatment of Pneumocystis carinii pneumonia (PCP) fell, but admissions for respiratory infections other than PCP remained very common, although they decreased slightly. Overall, infection remained the main reason for admission. The frequency of gastrointestinal complications necessitating admission increased. The frequency of admissions remained high, although the ALOS decreased significantly. In the period between Apr. 1, 1991, and Mar. 31, 1994, the proportion of HIV-related discharges and total hospital discharges among the 9 peer hospitals remained stable. The HIV-related ALOS decreased substantially. Although the HIV-related average RIW decreased slightly, this measure and the mortality rate are still much higher for HIV-related admissions than for overall admissions. CONCLUSIONS: This contemporary survey suggests that nonrespiratory infection complications have become the main reason for admission of patients with HIV infection or AIDS, but that the HIV tertiary hospitals are coping with the load of HIV-related admissions and the high average RIW associated with these patients by reducing the ALOS.

Female↗
PubMed1997

Cloning, sequencing, and embryonic expression of an N-ras proto-oncogene isolated from an enriched zebrafish (Danio rerio) cDNA library.

An enriched zebrafish (Danio rerio) complementary DNA library was constructed for screening of ras-related genes, and a positive clone was isolated from one plate of 3 x 10(4) plaques. This clone, Zras-B1, carried an insert of 2592 base pairs (bp) with an open reading frame encoding a ras p21 protein of 188 amino acids. The deduced amino-terminal 86 amino acid residues and the carboxy-terminal CAAX binding motif are identical to mammalian ras. The full-length Zras-B1-encoded protein is most closely related to human N-ras (91% identity), with lesser homology to Ha-ras (84%) and Ki-ras (85%). Preliminary screening data also indicate other ras genes in zebrafish, at least one of which is also transcribed in adults. A Zras-B1-related 3.1-kb transcript was found to be abundant in embryos from zygote through gastrulation, and may be maternally derived.

Amino Acid Sequence↗
PubMed1996

Community volunteers as recruitment staff in a clinical trial: the systolic hypertension in the elderly program (SHEP) experience.

During the recruitment phase of a trial it is often found that recruitment is not proceeding as quickly as projected. Budget limitations require innovative methods, such as use of volunteers, to increase recruitment yields without increasing cost. In the Systolic Hypertension in the Elderly Program (SHEP), volunteer staff at 12 of the 16 clinical centers (CCs) performed a range of tasks such as mailings, telephoning, and clerical work. SHEP volunteers donated almost 40,000 hours, at an estimated cost savings to the program of more than $368,000. Staff volunteers appear to require more training and supervision than regular staff and may require flexible work schedules. These limitations can be obviated by careful planning. This paper describes the SHEP experience with staff volunteers and provides suggestions for their use in other trials.

Aged↗
PubMed1996

Effect of retinoic acid on contractile competence of vascular smooth muscle.

Rat aortic rings cultured for 24 h in protein-free medium showed a significant reduction in the contractile response to potassium (-60%) and to phorbol 12,13-dibutyrate (-65%). The addition of plasma to the medium attenuated the loss in responsiveness, and the supplementation of the plasma-containing medium with all trans-retinoic acid (RA) returned the response to potassium (85%) and phorbol ester (135%) to near normal or supramaximal compared with fresh tissue. Furthermore, the combined additions of plasma and RA resulted in significant preservation of the contractile response (75%) for at least 3 days in organ culture. Removal of the endothelium before organ culture eliminated the enhancement of contraction by plasma and RA. However, the removal of the endothelium from tissues that had been cultured with an intact endothelium or the blockade of nitric oxide synthesis in these tissues before contractile measurements had no effect on the contractile response. Finally, the incubation of tissues with phorbol ester to downregulate protein kinase C resulted in a marked attenuation (-75%) of the contractile response compared with control tissues in culture. The results suggest that circulating factors may be necessary for the maintenance of contractile function of aortic smooth muscle. Based on the opposing actions of RA and phorbol ester, the long-term regulation of contractile function may involve protein kinase C activity.

Animals↗