Search PubMedSearch

Biomedical subjects

D M Foley

Publications and source records attributed to D M Foley.

6 recordsLinked to original sources

Rabbit model of Lyme borreliosis: erythema migrans, infection-derived immunity, and identification of Borrelia burgdorferi proteins associated with virulence and protective immunity.

Erythema migrans (EM), persistent skin infection, and visceral dissemination can be induced reproducibly in the adult male New Zealand White rabbit by intradermal injection of as few as 10(3) Borrelia burgdorferi. EM was found to persist for 7 +/- 3 d. Skin culture positivity (infection) cleared within a mean of 6.7 +/- 1.4 wk after infection and similarly visceral infection was not demonstrated after 8 wk; infection-derived immunity to intradermal challenge was evident 5 mo after initial infection. The extent of the protection against EM and dermal infection induced by untreated infection was directly related to the extent of prior in vitro passage of the B31 strain. Initial infection with as few as 4 x 10(3) B31 passage 4 induced complete protection against EM and skin infection upon subsequent challenge with 4 x 10(7) B31, passage 4. Initial infection with B31 passage 27 led to partial protection against EM along with complete protection against skin infection. Initial infection with passage 47 led to partial protection against EM, but conferred no protection against skin infection. Using serum from rabbits fully immune to reinfection, we defined a set of B. burgdorferi proteins present in virulent B31, but absent in the avirulent American Type Culture Collection B31 strain, termed "va" for virulent strain associated. The va proteins of B31 passages 1, 27, and 47 differed strikingly, thus raising the possibility that these changes may relate in a causal way to the differences in induction of protective immunity observed.

Animals

Virulent strain associated outer membrane proteins of Borrelia burgdorferi.

We have isolated and purified outer membrane vesicles (OMV) from Borrelia burgdorferi strain B31 based on methods developed for isolation of Treponema pallidum OMV. Purified OMV exhibited distinct porin activities with conductances of 0.6 and 12.6 nano-Siemen and had no detectable beta-NADH oxidase activity indicating their outer membrane origin and their lack of inner membrane contamination, respectively. Hydrophobic proteins were identified by phase partitioning with Triton X-114. Most of these hydrophobic membrane proteins were not acylated, suggesting that they are outer membrane-spanning proteins. Identification of palmitate-labeled lipoproteins revealed that several were enriched in the OMV, several were enriched in the protoplasmic cylinder inner membrane fraction, and others were found exclusively associated with the inner membrane. The protein composition of OMV changed significantly with successive in vitro cultivation of strain B31. Using antiserum with specificity for virulent strain B31, we identified OMV antigens on the surface of the spirochete and identified proteins whose presence in OMV could be correlated with virulence and protective immunity in the rabbit Lyme disease model. These virulent strain associated outer membrane-spanning proteins may provide new insight into the pathogenesis of Lyme disease.

Animals

The phenomena of care in Sicilian-Canadian culture: an ethnonursing case study.

This study examined the caring beliefs and behaviors of first- and second-generation Sicilians who immigrated to Canada and now reside in an Ontario metropolitan area. Madeleine Leininger's ethnonursing model of "Cultural Care Diversity and Universality" (1978, 1985, 1988) provided the framework; qualitative information was gained from the perceptions and cognitions of two Sicilian-Canadian families. Emphasis was placed on cultural and social structure dimensions that depicted caring, health beliefs, and related practices. The research questions guiding this inquiry were: a) What care values, care beliefs, and behavior patterns are deemed to promote/preserve well-being in this culture? b) Who provides care in this culture and under what circumstances? Implications for nursing that emerged included: provision of continuity of care, the importance of the involvement of the family, and the development of innovative means to enhance self-care practices to prevent illness and to reduce aversion to the professional healthcare system.

Attitude to Health

Exercise program for wheelchair activity.

Poor physical fitness of wheelchair-dependent individuals may result in excessive cardiorespiratory responses during locomotion. The purpose of this study was to develop and implement an interval training program (ITP) incorporating wheelchair ergometer (WERG) exercise to improve fitness for wheelchair activity. Of thirteen able-bodied female volunteers, seven were selected to participate in a 5-week ITP, while the remainder served as sedentary controls. Both the exercise training (ET) group and the sedentary control (SC) group completed a standardized fitness test on the WERG before (pre-test) and after (post-test) the 5-week period. Following the ITP, submaximal heart rate, pulmonary ventilation and oxygen uptake responses of the ET group were generally found to be significantly lower during the post-test. These improvements in WERG exercise performance were not observed in the SC group. The ITP may have contributed to adaptations of upper body muscles, improved cardiorespiratory function, and/or a higher level of skill for wheelchair propulsion. We conclude that applying the concepts of interval training to wheelchair exercise may substantially improve the performance and fitness characteristics of wheelchair users. This could reduce the relative stresses of wheelchair locomotion and lead to a higher level of rehabilitation.

Adolescent

An exercise test to evaluate fitness for wheelchair activity.

The purpose of this study was to develop a wheelchair ergometer (WERG) test to evaluate fitness for manual wheelchair activity. Thirty able-bodied females participated in a progressive intensity, discontinuous test where exercise bouts were 4 min in duration interspersed with 5-min rest periods. Physiological responses of oxygen uptake (VO2), respiratory exchange ratio (R), net mechanical efficiency (ME), pulmonary ventilation (VO) and heart rate (HR) were determined during the final minute of exercise at power output (PO) levels of 30, 60, 90, 120 and 150 kpm/min. These responses were generally found to be linearly related to PO, however, net ME initially increased with PO and plateaued at approximately 11 per cent at 90 kpm/min. Criteria for fitness evaluation were based upon: (1) magnitude of physiological responses at each PO level; and (2) the maximal PO level completed.

Adult