Biomedical subjects

S L Bernard

Publications and source records attributed to S L Bernard.

32 records · Page 2Linked to original sources

PubMed1997

Metropolitan versus nonmetropolitan differences in functional status and self-care practice: findings from a national sample of community-dwelling older adults.

The objective of this study was to use a recent national probability survey of the noninstitutionalized older adult population to compare the functional status and self-care practices of older adults residing in metropolitan and nonmetropolitan communities and to identify differences associated with residential location. The survey used in this study was the National Survey of Self-care and Aging (NSSCA). A cross-sectional design was employed using weighted bivariate and multivariate logistic regression analyses to examine the relationship between metropolitan and nonmetropolitan residential location and self-reported ability to perform basic, mobility, and instrumental activities of daily living (ADLs), as well as to assess the degree to which the levels and types of functional limitations affect metropolitan versus nonmetropolitan older adults' performance of self-care activities. The bivariate logistic analyses pointed to modest, often insignificant metropolitan versus nonmetropolitan differences in the ability to perform functional tasks. However, larger positive effects of nonmetropolitan residence were generally observed once other factors likely to account for some of these differences were taken into account. Older adults from nonmetropolitan areas were more likely to report being able to perform functional activities but also were more likely to report performing self-care activities both in the presence and absence of disability. This study, therefore, concluded that nonmetropolitan older adults may discount the significance of declining functional status, thus normalizing the trajectory of aging in a different way than do their metropolitan counterparts. If this process occurs, it may affect how nonmetropolitan persons use primary health care and/or long-term care services, challenging the economists' concept of demand, the clinicians' concept of need, and the policy analysts' concept of equity. Additional work is required to assess whether such a normalization process actually occurs and, if so, to explore its distribution, causes, correlates, and consequences.

Activities of Daily Living↗

PubMed1996

Gender and ethnic differences in alternative and conventional arthritis remedy use among community-dwelling rural adults with arthritis.

OBJECTIVE: To examine the frequency of, and the ethnic and gender differences in, the use of arthritis remedies among rural adults. METHODS: Interviews were conducted with 219 adults from a nonmetropolitan North Carolina county. Participants reported whether they ever used and still used 19 remedies. Participants were evaluated for the actual presence of arthritis and functional capacity. Analysis included descriptive statistics and multivariate logistic regression. RESULTS: Participants used a variety of alternative and conventional remedies, with prayer (92%) being most widely used. Prescription medicine was used by 60%. Differences in remedy use included European-Americans making greater use of conventional remedies and African-Americans making greater use of some alternative remedies. Those with greater functional disability have used alternative remedies, but they still used prescription medicine. CONCLUSIONS: Rural individuals use a variety of remedies, with differences by gender, ethnicity, and functional capacity. Future research must examine the role of gender, culture, residence, and disease severity in arthritis remedy use decisions.

Adult↗

PubMed1996

Bronchial circulation in the marsupial opossum, Didelphis marsupialis.

This study characterizes the existence of a bronchial circulation in a marsupial, an animal which does not undergo placental development and does not have a ductus arteriosus. Direct perfusion of the lung by the pulmonary vasculature during the fetal development of opossums may occur, potentially eliminating the need for a bronchial circulation. We used radio- and fluorescent-labeled microspheres in conjunction with postmortem intravascular casting to determine if opossums have a systemic (bronchial) blood supply to the lung (n = 9). Gross postmortem examination of the intravascular casts showed a well-developed common bronchial artery. The histological distribution pattern of fluorescent microspheres was primarily to the airways. A few fluorescent microspheres were observed in the alveolar capillaries, indicating that a precapillary bronchial-to-pulmonary anastomosis exists in the opossum. Using the reference flow technique, total bronchial blood flow to the left lung averaged 0.95 +/- 0.58 SE ml/min. The presence of a bronchial circulation in the opossum suggests that it is more than a vestigial structure from embryonic development, potentially supporting its functional importance for carrying nutrients to the airway.

Animals↗

PubMed1996

Older adults as a community resource: results from the National Survey of Self-Care and Aging.

Using data collected from the first wave of a longitudinal data set collected in the late fall and winter of 1990-1991, the National Survey of Self-Care and Aging (NSSCA), we examined the extent and type of assistance older people provided to others. Age, gender, and perceived health status were the most consistent predictors of the four types of assistance: personal care, child care, volunteer work, and listening/offering advice and support. Help with instrumental activities of daily living either alone or in combination with other activities of daily living was the most common type of personal care provided.

Activities of Daily Living↗

PubMed1996

Distribution of pulmonary and bronchial blood supply to airways measured by fluorescent microspheres.

This study determined the relative contributions of systemic (bronchial) and pulmonary blood flow to the intraparenchymal airways >1 mm in diameter by using 15-mu m fluorescent microspheres and fluorescence microscopy in four dogs. Fluorescent microspheres of one color were injected into the inferior vena cava as a pulmonary blood flow marker, and fluorescent microspheres of another color were injected into the left ventricle as a systemic blood flow marker. After the second injection, the animals were killed and the lungs were excised and air dried at total lung capacity. The left lung was sliced into transverse planes and then sectioned into smaller blocks containing airways down to 1 mm in diameter. The blocks were then sectioned using a Vibratome and examined with a fluorescence microscope. Pulmonary and systemic blood flow markers were counted in airway walls, and the diameter of each airway was measured to determine the bronchial tissue volume. After a correction for the number of blood flow markers injected into each circulation, the average ratio of pulmonary to systemic blood flow markers seen in airway walls was 1:37, indicating that 97% of the blood supply to the intraparenchymal airways down to 1 mm in diameter was from the bronchial circulation. Furthermore, on the basis of a weighted least squares regression analysis, systemic (bronchial) blood flow per unit tissue volume increased as airway diameter decreased (P = 0.03).

Animals↗

PubMed1996

Pulmonary blood flow distribution in standing horses is not dominated by gravity.

Recent studies using microspheres in dogs, pigs and goats have demonstrated considerable heterogeneity of pulmonary perfusion within isogravitational planes. These studies demonstrate a minimal role of gravity in determining pulmonary blood flow distribution. To test whether a gravitational gradient would be more apparent in an animal with large vertical lung height, we measured perfusion heterogeneity in horses (vertical lung height = approximately 55 cm). Four unanesthetized Thoroughbred geldings (422-500 kg) were studied awake in the standing position with fluorescent microspheres injected into a central vein. Between 1,621 and 2,503 pieces (1.3 cm3 in volume) were obtained from the lungs of each horse with spatial coordinates, and blood flow was determined for each piece. The coefficient of variation of blood flow throughout the lungs ranged between 22 and 57% among the horses. Considerable heterogeneity was seen in each isogravitational plane. The relationship between blood flow and vertical height up the lung was characterized by the slope and correlation coefficient of a least squares regression analysis. The slopes within each horse ranged from -0.052 to +0.021 relative flow units/cm height up the lung, and the correlation coefficients varied from 0.12 to 0.75. A positive slope, indicating that flow increased with vertical distance up the lung (opposite to gravity), was observed in three of the four horses. In addition, blood flow was uniformly low in three of the four horses in the most cranial portions of the lungs. We conclude that in lungs of resting unanesthetized horses, animals with a large lung height, there is no consistent vertical gradient to pulmonary blood flow and there is a considerable degree of perfusion heterogeneity, indicating that gravity alone does not play the major role in determining blood flow distribution.

Animals↗

PubMed1996

Minimal redistribution of pulmonary blood flow with exercise in racehorses.

We determined the spatial distribution of pulmonary blood flow at rest and during increasing levels of exercise (34, 59, and 90% of maximal oxygen consumption) in Thoroughbred racehorses (n = 4) using 15-microns fluorescent microspheres. After the horses were killed, the lungs were flushed free of blood, removed, air-dried at total lung capacity, and sliced into isogravitational planes, which were sampled in a systematic fashion for three-dimensional reconstruction. The fluorescence was measured for quantification of blood flow. Mean pulmonary blood flow heterogeneity (expressed as a coefficient of variation) did not change with increasing exercise levels [36.2 +/- 16.4 (rest) to 26.9 +/- 6.8% (gallop); P = not significant]. Greater than 70% of pulmonary blood flow variation across rest to high-exercise states is determined by a fixed spatial pattern. Thirty percent of the variation in pulmonary blood flow seen in horses over rest and exercising states is due to redistribution. The majority of flow redistribution was due to flow increasing to the dorsal region of the lung during exercise at 90% of maximal oxygen consumption (a flow gradient of 0.20 ml. min-1.cm-1 up the lung; P = 0.04).

Animals↗

PubMed1995

Self-care and assistance from others in coping with functional status limitations among a national sample of older adults.

Using data from the first wave of a new longitudinal data set collected in the late fall and winter of 1990-1991, the National Survey of Self-Care and Aging (NSSCA), we examined older adults' self-care practices in coping with functional status limitations based on in-person interviews with a national probability sample of 3,485 noninstitutionalized adults aged 65 or older selected from Medicare beneficiary files. A composite score of functional status was calculated to reflect the presence and severity of disability in three dimensions: basic, mobility, and instrumental activities of daily living. Three types of self-care coping strategies were defined: use of equipment or devices, changes in behavior, and modifications in one's environment. National estimates of self-care practices, assistance from others, and functional status measures were presented. Data revealed that the likelihood of engaging in self-care coping strategies increased as the severity of disability increased, except among the most severely disabled. Generally, those receiving assistance from others were more likely to engage in self-care activities, suggesting that receiving assistance supplements, rather than supplants, self-care coping strategies.

Activities of Daily Living↗

PubMed1995

The Mercedes incision in hair restoration.

Standard technique for hair transplantation includes plug composite grafts placed in circular recipient defects of smaller diameter. The plugs can also be placed in slit incisions that are temporarily dilated to accommodate grafts. Two drawbacks of these techniques are the appearance of row cropping resulting from the regular pattern and compression of individual grafts caused by scar contracture. These drawbacks result in tufting and a "doll's head" appearance. The expansile Mercedes incision as described here camouflages these failings. Donor minigrafts are taken with a biopsy punch knife or as strips in a standard fashion. A Mercedes logo-shaped defect is then made at the recipient site using a no. 11 scalpel to create a three-armed stellate incision. The incisions are rapidly made with the axis oriented parallel to the direction of the native hair shafts. The graft is then pushed in flush with the skin. The triangulation eliminates compression of grafts because they are spread in three directions rather than squeezing in a tight circular or slit configuration. The use of the stellate incision along with altering its rotational orientation in a haphazard pattern also prevents row cropping. Thus, the Mercedes incision is quicker and yields an overall improved result.

Alopecia↗

PubMed1993

Fifteen micrometer microspheres reflux up the pulmonary veins during pulmonary artery occlusion.

The systemic arterial blood supply to the lung (bronchial blood flow, Qbr) is commonly measured using the reference flow technique by injecting radiolabeled microspheres into the left atrium (LA) and simultaneously collecting a reference blood sample from a large artery such as the aorta. These measurements are often done with the pulmonary artery occluded prior to the time of injection. We have reported previously that left atrial blood refluxes up the pulmonary veins following pulmonary artery (PA) occlusion. We designed this experiment to determine if 15 mu microspheres reflux from the LA into the left lung (i) when the left PA is occluded prior to microsphere injection and (ii) when the left PA is open during the injection. We calculated Qbr to the left lung after simultaneous left ventricular (LV) and LA injections of different radiolabeled microspheres in anesthetized, closed-chest, prone goats. When the PA was open (but occluded 5 sec after the microsphere injection), Qbr calculated from an LA injection differed little from that calculated from an LV injection of microspheres. However, when the PA was occluded prior to injection of the microspheres, Qbr calculated from an LA injection was significantly higher than that calculated from an LV injection suggesting that microspheres reflux from the LA to the lung.

Animals↗

PubMed1991

The use of coralline hydroxyapatite in a "biocomposite" free flap.

An animal model was developed to determine the feasibility of vascularizing a porous biomaterial and transferring it as part of a free flap to a recipient site with enhanced resistance to infection due to the maintenance of a blood supply. To that end, the experiment was divided into three stages. Stage 1 compared the soft-tissue response of Interpore-200 to Interpore-500, both continuously porous hydroxyapatite materials implanted beneath the panniculus carnosus of the male Sprague-Dawley rat. Pore size was an important factor as it influenced vascular ingrowth, with Interpore-200 vascularizing earlier (complete at 1 week) and more intensely. Interpore-200 was therefore used for the remainder of the experiment. After 1 week of tissue ingrowth, the implants were moved from the abdomen to the skull on a vascular pedicle as a "biocomposite" free flap. Stage 2 was the histologic evaluation of 15 "biocomposite" free flaps over various time intervals up to 8 months. The free flaps formed a fibrous union to the skull, while a simple nonvascularized Interpore-200 onlay graft (stage 2 control) demonstrated a bony union in three of four implants placed up to 2 months. Stage 3 confirmed the free flap's resistance to bacterial infection. A highly significant difference (p less than 0.005) in infection rates was demonstrated between the "biocomposite" and nonvascularized stage 3 controls with no Pseudomonas growth from 9 of 10 cultures of the free flaps 5 days after exposure to 10(4) Pseudomonas aeruginosa, while stage 3 controls demonstrated Pseudomonas growth in all cultures (heavy growth in 8 of 10). The "biocomposite" free flap has excellent potential to provide form and structure to wounds requiring reconstruction where bacterial contamination is a significant risk factor.

Abdomen↗

PubMed1985

Acute continuous argon-laser induced tissue effects in the isolated canine heart.

Fresh isolated myocardial, elastic-arterial, and valvular tissues from seven canine hearts were irradiated by argon laser. Irradiation was transmitted through 300 and 400 micron flexible quartz fiberoptic elements. Minimal power densities for vaporization of the myocardial, arterial, and valvular tissues were 80, 90, and 110 W/cm2, respectively, with maximal vaporization distances (fiberoptic tip to tissue) of 4 mm, 1 mm, and 1 mm, respectively. Irradiation of the valves at power densities approaching perforation caused contraction of the tissue. When tissue vaporization occurred, histologic examination of irradiated tissues showed a central crater surrounded by sequential layers of char, vaporization, and coagulation necrosis. These findings were common to all cardiac tissues. Additional findings unique to myocardium were a normal-appearing myocardial layer (skip-area), circumferential halo, and tissue clefts. Elastic arteries showed concentration of necrosis around the collagen and elastic fibers. Valvular damage was the most extensive and also included contraction of adjacent valvular tissue and endocardial sloughing.

Animals↗

PubMed1983

Estrogen-induced bone marrow depression in ferrets.

The administration of estrogen-induced severe bone marrow depression in 9 of 12 ferrets, independent of sex (male, female) or ovariohysterectomy. Resultant pancytopenia was manifested by subcutaneous petechiae, melena, hematomyelia, pale mucous membranes, pale bone marrow, centrilobular hepatic degeneration, hydrometra, and pyometra. These findings are compatible with the naturally occurring estrus-associated anemia seen in female ferrets.

Anemia↗

PubMed1982

Antigen requirements and specificity of enzyme-linked immunosorbent assay for detection of canine IgG against canine distemper viral antigens.

An enzyme-linked immunosorbent assay (ELISA) was developed for detection of specific immunoglobulin G (IgG) against canine distemper virus (CDV) antigens. Sucrose gradient separation of viral and cellular proteins was required to produce coating antigens for the ELISA. The specificity of the ELISA was demonstrated by blocking CDV-positive canine sera with CDV-specific antisera produced in goats and rabbits and adsorption of positive sera with CDV antigens. A comparison of the ELISA with the serum-neutralization technique for the detection of CDV antibodies was conducted. Anti-CDV IgG was detected in conventional dogs as early as 6 days after inoculation with a commercial vaccine to CDV. Paired sera from the immunized dogs were evaluated by both techniques and a statistically (P less than 0.01) significant agreement between the ELISA and the serum-neutralization technique was shown (r = 0.6121, n = 75).

Animals↗