Efficacy of zanamivir for chemoprophylaxis of nursing home influenza outbreaks.

Despite vaccination, influenza remains a common of morbidity in nursing homes. Chemoprophylaxis of residents with currently available antivirals is not always effective and new agents effective against both influenza A and B are needed. In a randomized, unblinded pilot study, we compared 14 day chemoprophylaxis with zanamivir, an antiviral which inhibits influenza neuraminidase, to standard of care during sequential influenza A and influenza B outbreaks in a 735 bed nursing home. Influenza A outbreaks were declared on 6/14 epidemic units. Sixty-five volunteers on four epidemic units were randomized to zanamivir and on two epidemic units, 23 volunteers were randomized to rimantadine. During the 14 days of prophylaxis, only four new febrile respiratory illnesses were detected. One volunteer receiving rimantadine prophylaxis developed laboratory-confirmed influenza. Influenza B outbreaks were declared on 3/14 epidemic units. Thirty-five volunteers on two epidemic units were randomized to zanamivir and 18 volunteers on one epidemic unit were randomized to no drug. During the 14 days of prophylaxis, only one new febrile respiratory illness was detected. One volunteer randomized to receive no drug developed laboratory-confirmed influenza. Zanamivir appears comparably effective to standard of care in preventing influenza-like illness and laboratory-confirmed influenza in nursing homes, but requires further testing.

Watershed-based management strategies for the prevention and abatement of polluted agricultural runoff.

An increase in the average size of individual livestock production operations coupled with local and regional concentrations of these operations tend to increase negative environmental impacts in many watersheds. Environmental compliance strategies developed by the Texas Institute for Applied Environmental Research (TIAER) can be applied to reduce the negative impacts caused by livestock production and other types of agricultural activities. Further, the Institute's "planned intervention/micro-watershed approach" may provide the foundation for comprehensive solutions to environmental problems within a broad ecosystem management context.

Osteophytosis of the knee: association with changes in weight-bearing exercise.

Osteoarthritis has been held to result from wear and tear. We addressed this hypothesis by analysis of anteroposterior radiographs of the knees of 51 subjects with mean age of 60 years who regularly practiced weight-bearing exercise. Radiographs were assessed for longitudinal changes in spur formation over a two-year period. The results showed a negative association between changes in weight-bearing exercise and changes in the rate of spur development in both males and females. The findings suggest that increasing repetitive impulse loading in the form of regular painless weight-bearing activity does not promote osteophytosis (or perhaps degenerative disease) in knee joints.

Computerized tomographic evaluation of acetabular anatomy.

In this study, accurate identification of the location of the acetabular teardrop and ilioischial line on the cadaveric pelvis was attempted using computerized tomographic (CT) scanning and conventional roentgenographic techniques. The acetabular teardrops and ilioischial lines of four whole pelvic anatomic specimens were outlined with barium impregnated latex strings utilizing conventional roentgenograms, fluoroscopy, and stereoscopic control. Computed tomographic scanning was then performed, and axial and coronal CT reformations were created. Roentgenograms, CT scans, and magnetic resonance images of the pelves of ten patients with avascular necrosis of the femoral head were also reviewed to correlate the cadaveric study with specific clinical cases. The acetabular teardrop is a U-shaped figure on roentgenograms taken in a neutral anteroposterior projection. It is a complex geometric structure found to be in a constant position in the anteroinferior aspect of the acetabular wall. Its appearance changes with rotation of the pelvis or incident beam, as the teardrop represents a two-dimensional image of the tangents of a series of curves of varying radii. The ilioischial line is located posterior to the acetabulum and corresponds to tangents on the cortex of the posterior column. Computed tomography imaging with reconstruction identifies acetabular anatomy most clearly and allows precise measurements to be made.

Effect of changes in weight-bearing exercise on lumbar bone mass after age fifty.

This two year longitudinal study of 40 healthy subjects over age fifty (27 exercisers, 13 non-exercisers) was designed to evaluate the impact of weight-bearing exercise on lumbar bone mineral density as assessed by quantitative computed tomography. In both males and females exercising at moderate levels, a high correlation was found between changes in exercise and changes in bone density (r = 0.78 and 0.91, respectively P less than 0.002). For extreme levels of exercise (greater than 300 min/week in females over age fifty, and greater than 200 min/week in males over age seventy) bone density was low, confirming earlier cross-sectional results. Subjects without change in their exercise levels and non-exercisers lost similar amounts of bone. Increasing body mass index was identified as a protective factor with regard to lumbar bone loss. We conclude that in exercisers continuation of weight-bearing exercise is mandatory to prevent excessive bone loss. Extreme levels of exercise may be detrimental to bone density in subjects over age fifty years.

Case report 663. Unusual chondroblastoma of the scapula.

We have presented an unusual case of chondroblastoma mimicking a malignant tumor. Retrospective review of radiographs obtained 19 years before the diagnosis gave us a unique opportunity to follow the natural history of this atypical lesion.

Plain radiographs can be useful in estimating lumbar bone density.

On standard lateral roentgenograms of the lumbar spine, a decrease in bone density is said to be detectable only after a bone loss of about 40%. To evaluate this view, we compared findings on plain films with bone mineral content of L1 determined by quantitative computed tomography in 80 healthy subjects with a mean age of 60 years. The highest correlations with bone mineral content were found for the criteria "vertebral density versus soft tissue" (r = 0.5, p less than 0.0001), the "amount of trabeculations" (r = 0.49, p less than 0.0001), and for the "overall" estimate of osteopenia in the vertebra (r = 0.55, p less than 0.0001). Surprisingly, these three radiographic criteria proved to be most helpful in subjects with bone mineral content above 110 mg/cm3 (nonosteoporotic range). We conclude that lateral radiographs of the lumbar spine can provide a rough estimate of bone density in nonosteoporotic subjects which may be helpful in determining when further analysis with more precise methods is appropriate.

Benign metastasizing giant-cell tumor of bone. Report of three cases and review of the literature.

Three cases of benign giant-cell tumor (GCT) of bone with pulmonary metastasis are reported. In addition, 28 cases from the literature are reviewed. The patients were followed for a mean of 7.8 years (range from two to 29 years). The interval to metastasis ranged from zero to ten years with a mean of 3.2 years. Metastasis was not related to the number of previous operations. The local recurrence rate in the tumors that metastasized was 63%, suggesting that GCTs that metastasize may be an aggressive form of the tumor. The overall mortality rate was 16%. Persistent pulmonary disease does not carry a poor prognosis; surgical resection of accessible pulmonary nodules is recommended to provide histologic confirmation of the diagnosis, and prevent future complications secondary to local growth of the implants, as well as provide a potential cure. Chemotherapy has not improved survival and is associated with significant morbidity and is thus not recommended. Adjuvant radiation is recommended only for control of surgically unresectable lesions because of its potential association with sarcomatous degeneration in GCT.

Osteoarthritis in the hand: a comparison of handedness and hand use.

Osteoarthritis (OA) of the hand has been suggested to be the result of "wear" and "tear." If so, OA should develop more frequently in the dominant hand. We compared dominant with nondominant hands of 134 consecutive community subjects aged 53-75 by questionnaire, radiographs of hands, and rheumatologic evaluation. Mean age was 60 years, 93% were right handed, and 95% were in occupations classified as nonphysical. Subjects estimated dominant hand use of 2-10 times the amount of the nondominant hand. OA was found in 133 of 134 subjects. No radiologic or clinical differences were found between the dominant and nondominant hands. Twenty-six subjects who self-reported heavier lifetime hand use had somewhat greater clinical and hand radiographic OA scores than the 36 subjects reporting lighter hand use (43.5 vs 34.5) (p less than 0.01). In our study population, OA was not more prevalent in the dominant hand.

Long-distance running, bone density, and osteoarthritis.

Forty-one long-distance runners aged 50 to 72 years were compared with 41 matched community controls to examine associations of repetitive, long-term physical impact (running) with osteoarthritis and osteoporosis. Roentgenograms of hands, lateral lumbar spine, and knees were assessed without knowledge of running status. A computed tomographic scan of the first lumbar vertebra was performed to quantitate bone mineral content. Runners, both male and female, have approximately 40% more bone mineral than matched controls. Female runners, but not male runners, appear to have somewhat more sclerosis and spur formation in spine and weight-bearing knee x-ray films, but not in hand x-ray films. There were no differences between groups in joint space narrowing, crepitation, joint stability, or symptomatic osteoarthritis. Running is associated with increased bone mineral but not, in this cross-sectional study, with clinical osteoarthritis.

Hypertrophic osteoarthropathy of chronic inflammatory bowel disease.

The case of a 14-year-old girl with painful periostitis and ulcerative colitis is reported. The association of chronic inflammatory bowel disease with osteoarthropathy is rare and has previously been reported in eight patients. The periosteal reaction found in association with inflammatory bowel disease is apparently related to a chronic disease course and may cause extreme localized pain.

The behaviour of f2 coliphage in activated sludge treatment.

A model activated sludge treatment plant was used which was functionally very similar to a full-scale plant. It was inoculated with f2 coliphage and the titres of virus in the influent, the mixed liquor and the effluent were monitored regularly. The distribution of the virus in the solids and liquid fractions of the mixed liquor was in the ratio of 18:82 and 20.4% of the influent virus was recovered in the effluent. After inoculation was stopped the titre of virus in the solids fraction of the mixed liquor remained high and unaltered for up to 70 h, whereas the value for effluent reverted to the low background titre originally present. These results are discussed in relation to those reported for poliovirus and it is concluded that f2 coliphage is not a suitable model for studies of the behaviour of human enteroviruses.

The persistence of poliovirus of poliovirus in activated sludge treatment.

A model activated sludge treatment plant was used which was functionally very similar to a full scale plant. It was inoculated with poliovirus either continuously or with a single dose and the amounts of virus in the influent, mixed liquor and effluent were monitored regularly. The distribution of the virus in the liquid and solid phases of the mixed liquor was very unequal with about 85% of the virus associated with the suspended solids fraction. Only small amounts of virus were recovered from the effluent and after inoculation was stopped virus rapidly became indetectable. The efficiency of the plant with regard to removal of virus was closely related to its capacity to remove suspended solids and the adsorption of virus to solids and its inactivation is briefly discussed.

Humeral hypertrophy in response to exercise.

We compared roentgenograms of the jumeri of a group of professional tennis players and showed that there was pronounced hypertrophy of bone on the playing side. The cortical thickness on that side was greater by 34.9 per cent in men and 28.4 per cent in women compared with the control side. This represents a highly significant hypertrophy of bone in response to exercise.