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Biomedical subjects

N E Lane

Publications and source records attributed to N E Lane.

At least 73 records · Page 4Linked to original sources
PubMed1997

Pediatric emergency physicians and communicable diseases: can we be trusted to take care of ourselves?

OBJECTIVE: To determine if pediatric emergency physicians (PEP) are following Centers for Disease Control and Prevention (CDC) recommendations that all health care workers receive routine vaccines and annual tuberculosis screens. DESIGN: A two-page mail survey with one follow-up mailing. PARTICIPANTS: All active members of the American Academy of Pediatrics (AAP), Section on Emergency Medicine. Additional inclusion criteria were completion of training and employment in an emergency setting. RESULTS: Of 407 surveys, 286 (60%) were returned; 209 met inclusion criteria. Proof of immunization was not required of 43% of PEP; 42% were not required to have an annual tuberculosis (TB) screen. PEP reported immunity to the following: polio (95%), measles (94%), hepatitis B (91%), rubella (90%), mumps (90%), varicella (90%), and diphtheria-tetanus (86%). However, only 72% received a TB screen, and 60% received an influenza vaccine within the past year. Proof of vaccination for employment was required by 57/85 hospitals, 47/79 universities, and 6/32 self-employed/group practices (chi 2, P < 0.001). Proof of an annual TB screen was required by 64/87 hospitals, 44/82 universities, and 8/32 self-employed/group practices (chi 2, P < 0.001). PEP were more likely to have had a recent annual TB screen if required by their employer (104/117) than if left to their own initiative (42/87) (chi 2, P < 0.001). CONCLUSIONS: Although PEP are well protected against most vaccine-preventable diseases, many are not receiving annual TB screens nor influenza vaccines. The CDC guidelines are not being routinely followed by PEP.

Adult↗
PubMed1997

Acetabular dysplasia and osteoarthritis of the hip in elderly white women.

OBJECTIVES: To examine the association of acetabular dysplasia and osteoarthritis (OA) of the hip among elderly white women. METHODS: Pelvic radiographs from a sample of 165 white women aged 65 and above with radiographic hip OA and 88 white women aged 65 and above without radiographic changes of hip OA were read for evidence of acetabular dysplasia by a single trained investigator. Acetabular dysplasia was assessed using measurements of the centre edge angle and the acetabular depth, which are both reduced in this condition. Odds ratios for the association between acetabular dysplasia and hip OA were estimated using logistic regression analysis. RESULTS: Fourteen (3.4%) hips had a centre edge angle < 25 degrees, 46 (11.2%) hips had an acetabular depth of < 9 mm, and 54 (13.2%) hips had acetabular dysplasia defined as either of the above. Hips with OA had a small, but not statistically significant, increased prevalence of abnormal centre edge angle (odds ratio: 1.43; 95% confidence intervals: 0.46, 4.46), abnormal acetabular depth (1.47; 0.78, 2.77) and acetabular dysplasia (1.33; 0.74, 2.40). CONCLUSION: These results do not support the hypothesis that mild acetabular dysplasia accounts for a substantial proportion of hip OA in elderly white women. A study with a much larger sample size would be required to rule out a weak association between dysplasia and hip OA of the magnitude actually observed in our study.

Acetabulum↗
PubMed1997

Aspirin and nonsteroidal antiinflammatory drug use in elderly women: effects on a marker of bone resorption. The Study of Osteoporotic Fractures Research Group.

OBJECTIVE: Epidemiological studies suggest nonsteroidal antiinflammatory drug (NSAID) and aspirin use is associated with a modest increase in bone mineral density of the hip and lumbar spine. The ability of NSAID to block prostaglandin E2 production has been shown to impair osteoclast activity in animal models. To determine if regular use of these compounds inhibits bone resorption, we assessed NSAID or aspirin use and N-telopeptide crosslink excretion in elderly postmenopausal women. METHODS: N-telopeptide crosslink excretion was assessed from a consecutive sample of 499 women from the Study of Osteoporotic Fractures, age > 65 years, who provided a morning urine sample. Questionnaire, examination, and bone mineral density data were obtained at the same visit. RESULTS: In unadjusted models, daily use of NSAID or aspirin was associated with a reduction of 12.5% (95% CI 0.5, 24.5) in N-telopeptide crosslink excretion (p < 0.05). After adjustment for potential confounders, N-telopeptide crosslink excretion was -4.8% (95% CI -24.4, 14.8) in NSAID users and +7.6% (-9.3, 24.5) in aspirin users compared to nonusers. CONCLUSION: Regular use of either NSAID or aspirin by elderly women was not associated with reduction in N-telopeptide crosslink excretion compared to nonusers.

Aged↗
PubMed1997

Pain management in osteoarthritis: the role of COX-2 inhibitors.

Pain is the major symptom that leads patients to consult their physicians for the treatment of arthritis; therefore, effective pain control is an important goal in the management of this disorder. Pharmacologic therapy begins with simple analgesics and education. In many patients, simple analgesics do not adequately control moderate arthritis pain, and nonsteroidal antiinflammatory drugs (NSAID) are substituted for or added to the analgesic therapy. While NSAID are effective in controlling pain in mild to moderate osteoarthritis (OA), they are associated with significant toxicity (most frequently gastrointestinal) and may even cause complications that result in death. Patients who experience the pain associated with arthritis would therefore benefit from the antiinflammatory and analgesic actions of agents that are devoid of significant toxicities. Cyclooxygenase-2 (COX-2) inhibitors are being evaluated in clinical trials or are in development. These agents appear to inhibit only the COX-2 isoenzyme, which is produced largely during inflammation and is responsible for the biosynthesis of prostaglandins and other mediators of inflammation as well as sensitizers to pain. Because COX-2 inhibitors do not inhibit COX-1 isoenzyme activity at pharmacologic concentrations, they are devoid of many of the toxicities that are typical side effects of NSAID. Short term studies in dental pain, OA, and rheumatoid arthritis found that the COX-2 inhibitor celecoxib was an effective analgesic but did not cause gastroduodenal erosions. It has the potential to provide analgesia and antiinflammatory action in patients with arthritis without the side effects of NSAID. Further studies are required to substantiate these findings.

Aged↗
PubMed1997

Enlarged acetabular labra in the Pima Indians.

OBJECTIVE: To report the descriptive epidemiology of acetabular labral enlargement and analyze associations of other variables with this variant. METHODS: Pelvis radiographs from 761 Pima Indians aged > or = 45 years enrolled in a population based study were read by Kellgren-Lawrence global and individual radiographic features grading scales for osteoarthritis (OA) at separate settings. In total, 722 radiographs remained eligible for this study after excluding 12 unreadable radiographs and 27 cases of radiographic hip OA (Kellgren-Lawrence grade > or = 2). Enlarged acetabular labra were recorded during readings of individual radiographic features. RESULTS: Enlarged acetabular labra were present in 16% of study participants without OA and were significantly associated with female sex, but not with the variables age, body mass index, clinical hip joint involvement, diabetes, or serum insulin concentrations. CONCLUSION: Acetabular labral enlargement is common in the Pima Indians, and although not in excess of other reported acetabular margin anomalies, it differs in appearance and is not associated with age. Recognition of this structural variant is important because it can mimic fractures or osteophytes.

Acetabulum↗
PubMed1996

Association of estrogen replacement therapy with the risk of osteoarthritis of the hip in elderly white women. Study of Osteoporotic Fractures Research Group.

OBJECTIVE: To determine whether postmenopausal estrogen replacement therapy is associated with a reduced risk of radiographic findings of osteoarthritis (OA) of the hip. DESIGN: Cross-sectional study. SUBJECTS: White women (N = 4366; age, > or = 65 years) who were participants in a cohort study of osteoporotic fractures. MEASUREMENTS AND METHODS: Radiographs of the pelvis that were obtained in all subjects were assessed for radiographic features of OA of the hip on a summary scale of 0 (none) to 4 (severe OA). Postmenopausal estrogen use was assessed by interview. The association of current and past oral estrogen use with OA of the hip was analyzed by using logistic regression, adjusting for potential confounding variables (eg, indicators of osteoporosis and correlates of estrogen use). RESULTS: Five hundred thirty-nine women (12.3%) had mild or greater radiographic findings of OA of the hip in at least 1 hip, and 214 women (4.9%) had moderate to severe findings; 17% and 24% of the women were current and past users of oral estrogen, respectively. Women who were currently using oral estrogen had a significantly reduced risk of any OA of the hip (adjusted odds ratio [OR], 0.62; 95% confidence interval [CI], 0.49-0.86) and moderate to severe manifestation of disease (OR, 0.54; 95% CI, 0.33-0.88). Current users who had taken estrogen for 10 years or longer had a greater reduction in the risk of any OA of the hip (OR, 0.57; 95% CI, 0.40-0.82) compared with that of users for less than 10 years (OR, 0.75; 95% CI, 0.47-1.24). Current estrogen use for 10 years or longer was associated with a nonsignificant trend for a reduced risk of moderate to severe symptomatic disease (OR, 0.59; 95% CI, 0.28-1.29). CONCLUSION: Postmenopausal estrogen replacement therapy may protect against OA of the hip in elderly white women.

Aged↗
PubMed1996

Aspirin and NSAID use in older women: effect on bone mineral density and fracture risk. Study of Osteoporotic Fractures Research Group.

Prostaglandin inhibition by aspirin or nonsteroidal anti-inflammatory drug (NSAIDs) may inhibit bone loss and preserve bone mineral density (BMD) in vitro and in animal models. The effect of these agents on BMD and fracture risk in postmenopausal women in unknown. We assessed the risk factors for osteoporosis and the use of aspirin and NSAIDs in 7786 white women over age 65. Axial BMD was measured at the same time, and fractures were prospectively documented over the subsequent 4 years of follow-up. In age-adjusted analyses, daily use of aspirin or NSAIDs was associated with a 2.3-5.8% increase in BMD of the hip and spine. The relationship persisted even after adjustment for weight, a variety of medications, self-reported arthritis, and for radiographic findings of osteoarthritis, but the multiply adjusted increase in BMD was only 1.0-3.1%. Fracture risk was similar among daily users of aspirin and NSAIDs and nonusers. After adjustment for potential confounders, among daily aspirin users the relative risk of hip fracture was 1.1 (95% confidence interval [CI]: 0.7, 1.6), and among daily NSAID users the risk was 0.9 (CI: 0.6, 1.4). Considering all nonspine fractures together, the risk among aspirin users was 1.0 (CI: 0.8. 1.2), and among NSAID users the risk was also 1.0 (CI; 0.8, 1.2). Regular use of aspirin or NSAIDs may have a modest beneficial effect on BMD in postmenopausal women. This effect persists after adjustment for obesity and the presence of osteoarthritis. However, among women who take aspirin or NSAIDs regularly, there is no clinically significant protective effect on the subsequent risk of fractures.

Aged↗
PubMed1996

Bone-selective analogs of human PTH(1-34) increase bone formation in an ovariectomized rat model.

Intermittent parathyroid hormone (PTH) therapy increases bone mass. The purpose of this study was to determine if analogs of human PTH(1-34) (hPTH[1-34]), which differ from the native sequence in their receptor-activating properties, could promote bone formation in an ovariectomized (OVX) osteopenic rat model. We synthesized two hPTH(1-34) analogs with single substitutions for serine in the 3-position that in vitro are partial agonists in kidney. In the renal cell line OK, maximal cyclic adenosine monophosphate (cAMP) activation by [His(3)]hPTH(134) was 50%, and maximal cAMP activation by [Leu(3)]hPTH(1-34) was 20% of that produced by hPTH(1-34). Both analogs were full agonists in UMR-106 rat osteosarcoma cells and other bone-derived systems, but both had reduced potency compared with hPTh(1-34). Six-month-old retired breeder Sprague-Dawley rats were ovariectomized, and five animals underwent sham operation. On day 56 post-OVX, five sham-operated and five pre-PTH treatment OVX animals were sacrificed, and the remaining animals were randomized into 10 groups of six animals each. All other animals were injected with one of the hPTH analogs or hPTH(1-34) at 0, 4, 40, or 400 mu g/kg of body weight (BW)/day and were killed on day 84. Histomorphometry of the proximal tibia metaphysis and biochemical markers of bone turnover (osteocalcin and pyridinoline cross-links) were the primary endpoints. The cancellous bone volume was significantly lower at day 56 post-OVX (pretreatment) and at day 84 post-OVX (post-vehicle treatment) than at baseline. None of the compounds significantly increased the cancellous bone volume. Trabecular number declined after OVX and did not change with hPTH treatment. In contrast, the trabecular thickness declined after OVX but was higher after treatment with 40 mu g/kg of BW/day or 400 mu g/kg of BW/day of hPTH(1-34). In OVX rats, the mineralizing surface was higher than baseline at day 56 and fell toward control levels by day 84. All three peptides produced marked dose-related increases in the mineralizing surface and bone formation rates, but the two analogs were less potent than hPTH(1-34). Likewise, all peptides produced significant dose-related increases in the serum osteocalcin level. The osteoclast surface was not affected by OVX but was decreased with medium and high doses of hPTH(1-34). Pyridinoline cross-link excretion was not significantly affected by treatment with hPTH(1-34) but responded with a dose-dependent decrease to treatment with [His3]hPTH(1-34). These data suggest that bone selective analogs of hPTH(1-34) maintain the ability to induce bone formation but are less potent than hPTH(1-34).

Animals↗
PubMed1996

Bone mineral density and turnover following forelimb immobilization and recovery in young adult dogs.

The purpose of this experiment was to study changes in bone mass, structure, and turnover in the canine forelimb after unilateral immobilization and recovery. The right forelimbs of 14 adult mongrel dogs were immobilized for 16 weeks. Six dogs served as controls. Seven immobilized and three control dogs were euthanized at the end of the immobilization period. Recovery consisted of 16 weeks of kennel confinement followed by 16 weeks of treadmill exercise. Seven once-immobilized and three control dogs were euthanized at the end of the recovery period. Bone mineral density of both the proximal (PBMD) and central (CBMD) radius was determined by dual X-ray absorptiometry. Standard histomorphometric endpoints for bone mass and turnover were determined in the cancellous bone of the proximal radius. After immobilization, PBMD, CBMD, and trabecular thickness were lower in the immobilized limb than in either the contralateral or control limbs (P < 0.05). Only CBMD remained significantly lower (P < 0.05) after recovery. At the end of immobilization, bone formation endpoints were significantly higher in the immobilized limb than both the contralateral and control limbs. Bone turnover was also significantly lower in the contralateral limb than in the immobilized and control limbs. After recovery, all differences in bone turnover had resolved. Immobilization of 16 weeks duration caused an elevation in cancellous bone formation rate and reduced bone density in both cortical and cancellous bone. After 32 weeks of recovery, turnover abnormalities disappeared, cancellous bone normalized, but cortical bone mass remained low. Recovery of cortical bone from immobilization takes longer than recovery of cancellous bone.

Animals↗
PubMed1996

Recreational exercise in arthritis.

For the person with arthritis, the consequences of prolonged inactivity add measurably, and unnecessarily, to disease-related impairments, functional limitation, and disability. Inadequate levels of regular physical activity also increase the risk of cardiovascular disease, hypertension, diabetes, and obesity. This article reviews the benefits of regular physical activity for general health as well as the literature on conditioning exercise in rheumatoid arthritis and osteoarthritis. Recommendations and guidelines are given for including conditioning exercise in comprehensive management.

Arthritis↗
PubMed1996

Physical activity at leisure and risk of osteoarthritis.

A summary of the evidence linking exercise and osteoarthritis is given in the table. In summary, normal joints appear to tolerate prolonged vigorous low impact exercise without accelerated development of osteoarthritis. The risk of developing osteoarthritis appears to be increased in sporting activities that continually expose normal joints to high levels of impact or torsional loading and in individuals who continue sporting activities after they have injured supporting structures in the joint (like ligaments, tendons, and menisci). The hypothesis that high impact loads to joints over time will accelerate the development of osteoarthritis in exposed joints must now be examined in a longitudinal study.

Biomechanical Phenomena↗
PubMed1996

Osteoporosis and systemic lupus erythematosus: etiology and treatment strategies.

The importance of bone loss in patients with systemic lupus erythematosus can not be over emphasized. Risk factors for osteoporosis in these patients include not only those that apply to the general population, but also many that are related to the underlying disease process, or its treatment. Ongoing research should attempt to clarify the prevalence of low bone mass in lupus, as well as the pathogenic mechanisms applying especially to this population. Strategies for the prevention and treatment of bone loss in lupus patients do not differ significantly from those in the general population. Special attention must be given to the prevention of steroid induced bone loss, as well as to the gonadal effects of cytotoxic agents.

Bone Density↗
PubMed1995

Radiographic osteoarthritis of the hip and bone mineral density. The Study of Osteoporotic Fractures Research Group.

OBJECTIVE: To examine the cross-sectional association between radiographic features of hip osteoarthritis (OA) and bone mineral density (BMD) of the hip, spine, and appendicular skeleton among Caucasian women ages 65 and older who were participating in the Study of Osteoporotic Fractures. METHODS: Pelvis radiographs of 4,855 subjects were assessed for individual radiographic features of hip OA: osteophytes, joint space narrowing, subchondral sclerosis, cysts, and femoral head deformity. Hips were graded on a summary scale of 0 (no OA) to 4 (severe OA) based on the number of radiographic features present. Appendicular BMD was measured in all subjects, and hip and spine BMD in 84% of the group. We used linear regression to examine the association of BMD with hip OA, and to adjust for age, weight, and other determinants of bone mass. RESULTS: Three hundred fifty-one women (7.2%) had mild (grade 2) and 228 (4.7%) had moderate to severe (grade 3-4) radiographic evidence of hip OA. Women with grade 3-4 hip OA had a higher age-adjusted BMD at the femoral neck and Ward's triangle (9-10%; P < 0.0001), trochanter (4%; P < 0.01), lumbar spine (8%; P < 0.0001), and distal radius and calcaneus (5%; P < 0.0001 [for each comparison]) compared with those with grade 0-1 OA in the worse hip. Elevations in BMD were greatest in the femoral neck of hips with OA, in women with bilateral hip OA, and in women with hip osteophytes. These findings were essentially unchanged by adjustment for determinants of bone mass. CONCLUSION: Elderly Caucasian women with moderate to severe radiographic hip OA had higher BMD in the hip, spine, and appendicular skeleton than did women without hip OA. Our findings are consistent with a role of elevated BMD in the pathogenesis of hip OA.

Aged↗
PubMed1995

Rheumatoid arthritis and bone mineral density in elderly women. The Study of Osteoporotic Fractures Research Group.

Previous studies have suggested that women with rheumatoid arthritis (RA) have decreased bone mineral density (BMD) in both the appendicular and axial skeleton. The purpose of this investigation was to determine the association of RA and BMD from a community-based sample of ambulatory Caucasian women age 65 and over. BMD was measured by dual-energy X-ray absorptiometry (DXA) at the hip and lumbar spine and by single photon absorptiometry (SPA) at the distal radius and calcaneus. Study subjects included 120 postmenopausal women with RA who were further classified according to corticosteroid use, i.e., never users, current users, and ex-users, and 7966 age-similar controls. Elderly women with RA had a lower age-adjusted bone density of the distal radius, calcaneus, hip, and lumbar spine. Women with RA who were current users of steroids had the lowest BMD at both appendicular sites and at the hip, but those who never used steroids also had a significantly decreased BMD at all sites. The BMD of women with RA who had never used steroids remained significantly decreased at the distal radius, calcaneus, and hip after adjustment for age, BMD determinants, and functional outcomes of RA. Functional outcomes of RA largely accounted for the lower BMD of women who were currently using steroids. Women with RA have lower appendicular and axial bone mass that is not attributable to the use of steroids. Those currently taking steroids have even lower appendicular and axial bone mass that may reflect their poorer functional outcome and is likely to increase the risk of fractures.(ABSTRACT TRUNCATED AT 250 WORDS)

Absorptiometry, Photon↗
PubMed1995

In vivo, three-dimensional microscopy of trabecular bone.

Osteoporosis, which is correlated with low bone mass and increased bone fragility, is responsible for about 1.2 million fractures per year in the United States. We have used the three-dimensional (3-D), X-ray tomographic microscope to image the trabecular bone architecture of the proximal tibias of six Sprague-Dawley rats in vivo. Three of these rats were then ovariectomized to induce estrogen depletion, and three remained as controls. Five weeks later, the tibias were reimaged. The ovariectomized rats lost approximately 65% of their trabecular bone volume as compared with an insignificant change in the control rats. The connectivity density of the trabecular bone, as measured by the Euler characteristic, was linearly correlated with trabecular bone volume, even in the ovariectomized rats. Hypoestrogenemic bone loss manifested itself in greatly reduced connectivity and fewer trabecular elements, but not in thinning of trabeculae. The ability to microscopically image sequential changes in the 3-D architecture of trabecular bone in vivo will allow exploration of the earliest stages of hypoestrogenemic bone loss and to more rapidly test the effectiveness of new clinical treatments for this major public health problem.

Animals↗
PubMed1995

Intermittent treatment with human parathyroid hormone (hPTH[1-34]) increased trabecular bone volume but not connectivity in osteopenic rats.

Previous studies have determined that intermittent parathyroid hormone (PTH) therapy increases bone mass and improves biomechanical strength in osteopenic animal models. The purpose of this investigation was to determine if intermittent human parathyroid hormone (hPTH[1-34]) therapy increased trabecular bone volume and connectivity in a rat model of established osteopenia using three-dimensional (3D) ex vivo in situ morphometry by X-ray tomographic methods (XTM). Six-month-old retired Sprague-Dawley breeder rats were used. Thirty animals were ovariectomized (OVX) and six were Sham operated. On day 56, post-OVX, a prePTH-treatment OVX groups was sacrificed. The remaining OVX animals were randomized into four groups of six animals each, given injections 5 out of every 7 days for 28 days of either vehicle or hPTH(1-34) at 4, 40, or 400 microg/kg of body weight (BW)/day and were sacrificed on day 84 post-OVX. At sacrifice, the left proximal tibias were harvested for XTM scans. hPTH(1-34) at medium and high doses significantly increased trabecular bone volume and trabecular thickness compared with ovariectomized animals treated with vehicle (p<0.05). The trabecular bone volume was equal to or greater than the Sham-operated animals in both hPTH(1-34) 40 and 400 microg/kg of BW treatment groups. Trabecular bone connectivity decreased by nearly 50% compared to the S ham-operated group at day 84 post-OVX and did not increase with any of the hPTH(1-34) treatments. Intermittent hPTH(1-34) treatment is osteopenic OVX rats increased trabecular bone volume to control levels or higher by thickening existing trabeculae. Human PTH(1-34) did not re-establish connectivity when therapy was started after 50% of the trabecular connectivity was lost. We hypothesize that to re-establish trabecular connectivity, a therapeutic intervention would have to be given before a significant distance between trabeculae has developed. Further studies will need to be done to refute or confirm our hypothesis.

Animals↗