High-dose alendronate uncouples osteoclast and osteoblast function: a study in a rat spine pseudarthrosis model

The effect of alendronate on osteoclast and osteoblast function was studied in a novel spine pseudarthrosis model in rats. Sixty-three Sprague-Dawley rats were divided into three groups: control group (saline), therapeutic dose group (1 microg/kg/week), and one-log overdose group (10 microg/kg/week). Animals had L4-L5 posterior intertransverse process fusion with limited bone graft and were sacrificed at 2, 4, and 6 weeks. Manual palpation showed no notable differences among groups. Treatment group radiographic scores were equal to or better than control group scores and were higher than the overdose group at 2 and 6 weeks. Qualitatively, limited histologic remodeling and poor osteoclastic and osteoblastic function were noted in the alendronate treated groups. Quantitative histologic analysis showed fewer osteoclasts in the therapeutic and high-dose groups (p < 0.001). The percent osteoblasts per bone surface area was lower in the high-dose group (p < 0.05). The results suggest that the effect of alendronate was dose dependent and animal model dependent and that supranormal doses of alendronate had a deleterious effect on osteoclastic and osteoblastic function in this model.     

Computerized frameless stereotactic image guidance in spinal surgery

Clinical applications of computerized frameless stereotactic image-guided spinal surgery continue to evolve. This article discusses several limiting factors regarding the use of this technology. It discusses the benefits of stereotaxy, which are better realized when there is a distortion of 'normal' anatomy because of previous surgery or severe deformity. The three-dimensional model helps the surgeon navigate the rotated and translated vertebrae. The technology can also be helpful when performing a posterior lumbar interbody fusion, to determine the orientation and depth of placement of the allograft or the cage.     

Efficacy of lamivudine therapy for advanced liver disease in patients with precore mutant hepatitis B virus infection awaiting liver transplantation

BACKGROUND: Orthotopic liver transplantation (OLT) for end-stage liver disease resulting from hepatitis B virus (HBV) infection is associated with a high rate of recurrence and reduced survival. Lamivudine is effective in inhibiting HBV replication in patients with chronic hepatitis. This study evaluated the impact of lamivudine on viral suppression, liver function, and disease severity in patients awaiting OLT with HBV e-minus strain infection. METHODS: Twenty-five patients received lamivudine (100 mg per day) from the day of listing for OLT. All patients were positive for serum HBV-DNA by polymerase chain reaction and all had a Child-Pugh score of 7 or higher. RESULTS: Patients were followed for 12+/-9 months (mean +/- SD). Eleven underwent OLT within 13 months of treatment initiation, one died after 10 months, and one dropped out after 3 months. After 3, 6, and 9 months, HBV-DNA by polymerase chain reaction was undetectable in 14 of 25, 14 of 20, and 13 of 15 patients, respectively. Two patients developed lamivudine resistance after 9 and 18 months of treatment, respectively, without liver decompensation. Comparing baseline to last visit data, a significant improvement in prothrombin activity (43+/-15% vs. 52+/-19%; P=0.0014), serum bilirubin (3.4+/-1.9 vs. 2.5+/-2.2 mg/dL; P=0.0007), serum albumin (3.3+/-0.3 vs. 3.6+/-0.5 g/dL; P=0.0278), presence of ascites (15/25 vs. 7/25; P=0.0047), and Child-Pugh score (9 vs. 8; P=0.0003) was observed. Because of liver function improvement, four patients were placed on low priority status for OLT (United Network of Organ Sharing 3) and 9 on inactive status (United Network of Organ Sharing 7). The overall probability of survival at 6 and 12 months was 100% and 90.9%, respectively. CONCLUSIONS: Lamivudine has an important role in patients with end-stage liver disease caused by HBV precore mutant strain. Not only does HBV-DNA suppression allow patients to be eligible for OLT, but the improvement of the patients' clinical status may delay the need for OLT in an era of organ shortage.     

A field investigation of the acute respiratory effects of metal working fluids. I. Effects of aerosol exposures

A study of cross-shift change in pulmonary function was conducted among workers exposed to metal working fluids (MWF) in an automobile parts manufacturing company. Three hundred eighty-six workers (216 machinists exposed to straight or soluble MWFs, and 170 nonmachinists) were studied for 1 day, performing spirometry at the beginning and end of their shift. Airborne concentrations of inhalable particulate, culturable bacteria, and endotoxin were measured. We observed an approximately threefold increase in the incidence of 5% or greater cross-shift decrement in forced expiratory volume during the first second among those with exposures above about 0.15 mg/m³, compared to those with exposures below about 0.08 mg/m³. There was some evidence that chronic respiratory symptoms were more prevalent among machinists than among nonmachinists, notably for chronic cough. Baseline FEV₁ was about 3% lower on average among those with soluble MWF exposure compared to nonmachinists. These findings are consistent with earlier studies showing respiratory effects of MWFs. Am. J. Ind. Med. 31:756–766, 1997. © 1997 Wiley-Liss, Inc.     

Ascariasis and trichuriasis in Cameroon

A national survey of Ascaris lumbricoides and Trichuris trichuria was carried out in Cameroon on more than 22,000 children from a random sample of 512 schools. Prevalence rates of both A. lumbricoides and T. trichuria infection were very low in the tropical zone (below 5%). They increased markedly in the equatorial zone, Guinea-type climate, to 60-85% for A. lumbricoides and 85-95% for T. trichuria. In the equatorial zone with Cameroon-type climate, prevalences were slightly lower: 50-70% for A. lumbricoides and 70-90% for T. trichuria infections. Environmental conditions are the main factors explaining these differences. Other factors (altitude, population density and urbanization) were not important. The entire population of villages selected from distinct climatic zones of Cameroon were also examined. The age group distribution of A. lumbricoides and T. trichuria infections indicated acquisition early in life, reaching a peak in early childhood, followed by a stable prevalence rate.     

Adenosquamous-cell carcinoma of the ovary: report of a case with positive peritoneal fluid cytology

Cytologic examination of peritoneal fluid showed only malignant squamous cells, without revealing adenocarcinomatous cell components, in a patient who had an endometrioid adenosquamous-cell carcinoma of the ovary. Histologic examination of the ovary demonstrated diffuse squamous-cell carcinoma with rare foci of endometrioid and abortive malignant glands, as well as isolated mucin-positive cells. The cytologic differential diagnosis of malignant squamous cells in peritoneal fluid and the pathogenesis of squamous-cell carcinoma of the ovary are discussed.