Temporal effects of a COX-2-selective NSAID on bone ingrowth

The effects of a short course of a COX-2 inhibitor on bone healing when the drug is discontinued are unknown. We examined the effects of rofecoxib on bone ingrowth over a 6-week period using a well-defined animal model. The Bone Harvest Chamber was implanted bilaterally in mature rabbits. After osseointegration of the chamber, the following treatments were given for 6 weeks each, followed by a harvest in each case: control-no drug; oral rofecoxib (12.5 mg/day) for the first 2 of 6 weeks; washout period-no drug; oral rofecoxib for the last 2 of 6 weeks; washout period-no drug; rofecoxib given continuously for all 6 weeks. Harvested specimens were snap-frozen, cut into serial 6-microm sections, and stained with hematoxylin and eosin and alkaline phosphatase (osteoblast marker), and processed using immunohistochemistry to identify the vitronectin receptor (osteoclast-like cells). Rofecoxib given continuously for 6 weeks yielded statistically less bone ingrowth compared to the control treatment. Rofecoxib given during the initial or final 2 weeks of a 6-week treatment did not appear to interfere with bone ingrowth. This suggests that the effects of COX-2 inhibitors on bone are less profound when the drug is administered for a short period of time.     

Hypoxia-induced renal epithelial cell death through caspase-dependent pathway: role of Bcl-2, Bcl-xL and Bax in tubular injury

Although injury of epithelial cells has been reported to be responsible for renal disease such as acute renal failure, its molecular mechanisms are largely unknown. As hypoxia has been postulated as the initial trigger of epithelial injury, we studied the molecular mechanisms of apoptosis induced by hypoxia in human renal epithelial cells. Severe hypoxia caused epithelial cell death, accompanied by a significant increase in LDH release (p<0.01). In addition, hypoxic treatment of epithelial cells resulted in a significant increase in apoptotic cells as assessed by cell morphology (p<0.01). The apoptotic change in epithelial cells under hypoxic condition was also confirmed by a significant increase in caspase-3-like activity and release of cytochrome c (p<0.01). The decrease in epithelial cell number was completely abolished by addition of a wide-spectrum caspase inhibitor, Z-VAD, rather than Z-DEVD, a specific caspase-3 inhibitor (p<0.01). Thus, we further studied the molecular mechanisms of apoptosis induced by hypoxia. Anti-apoptotic factors, Bcl-2 and Bcl-xL, were significantly decreased in epithelial cells under a hypoxic condition as assessed by Western blotting (p<0.01). In contrast, hypoxia did not alter their location. Of particular importance, translocation of a proapoptotic factor, Bax, from the cytoplasm to the mitochondrial membrane was observed in response to hypoxia, whereas total Bax protein was not changed by hypoxia. Overall, this study demonstrated that hypoxia caused epithelial cell death induced by caspase-3-like activity-dependent apoptosis. The pro-apoptotic mechanisms of hypoxia in epithelial cells largely depend on a significant decrease in Bcl-2 and Bcl-xL. In addition, the present results demonstrate that translocation of Bax from the cytosol to the mitochondrial membrane occurred under hypoxia, thereby leading to pathological tissue destruction.     

The value of needle biopsy in the diagnosis of musculoskeletal tumors

Background Percutaneous needle biopsy has many advantages over open biopsy in the treatment of neoplasms. However, the accuracy of the needle biopsy in the diagnosis of musculoskeletal tumors has not been established. It is essential to evaluate the accuracy and limitations of the procedure in musculoskeletal tumors. Methods The diagnoses from 66 needle biopsies (bone, 37; soft tissue, 29) performed on 64 consecutive patients using a jamshidi needle (bone tumors) or a Tru-cut needle (soft tissue tumors) were compared with the final diagnoses made by open biopsy and/or a definitive operation. Results Fifty-eight specimens (87.9%) were judged to be adequate for histological examination. It was technically difficult to obtain undamaged cores from very hard bony lesions or sclerotic cyst walls. A pathologist with experience in musculoskeletal tumors was able to differentiate malignant tumors from benign lesions in 98.3% of the cases (bone, 100%; soft tissue, 96.4%) and arrive at a specific diagnosis in 91.4% (bone, 100%; soft tissue, 82.1%) when adequate cores were obtained. It was troublesome to distinguish a well-differentiated liposarcoma from a benign lipoma, or inflammatory lesions from benign tumorous conditions. The overall accuracy for needle biopsy was 80.3% (bone, 81.1%; soft tissue, 79.3%). There was no morbidity related to the procedure. Conclusion The results indicate that meedle biopsy is a safe and accurate technique for diagnosing musculoskeletal tumors.     

Endovascular treatment for poorest-grade subarachnoid hemorrhage in the acute stage: has the outcome been improved?

OBJECTIVE: Patients with poor-grade subarachnoid hemorrhage (SAH) have been considered good candidates for endovascular treatment. The results of treatment of Grade V SAH, the poorest grade, however, have not been fully elucidated. METHODS: The clinical characteristics and outcome parameters of 22 World Federation of Neurosurgical Societies Grade V SAH patients treated endovascularly in the acute stage between 1998 and 2000 are summarized and compared with those of 18 Grade V SAH patients treated conservatively between 1995 and 1997. RESULTS: Among the 22 patients treated endovascularly, 8 patients (36.4%) survived. The rate was significantly higher than that of the 18 patients treated conservatively (5.6%), only one of whom survived. The favorable outcome rate, however, was not significantly different between the two groups (4.5% versus 6.0%). Subdivision of both treatment groups according to Glasgow Coma Scale (GCS) score showed that the improved survival among those treated endovascularly was attributable to the improved survival in those with a preprocedural GCS score of 6 but not of 4 or 5. CONCLUSION: Endovascular treatment of the 22 World Federation of Neurosurgical Societies Grade V SAH patients improved their survival rate but not their favorable outcome rate in comparison with conservative treatment. Further accumulation of clinical data is essential to determine whether endovascular treatment can improve the functional outcome of those with GCS scores of 6 and whether there is no role for endovascular treatment in those with GCS scores of 4 or 5.     

Preoperative and intraoperative evaluation of diameter-reflux relationship of calf perforating veins in patients with primary varicose vein

OBJECTIVE: Interruption of incompetent perforating veins (PVs) is important for varicose vein surgery. The purpose of this study was to evaluate the preoperative and intraoperative diameter-reflux relationship of PVs and to evaluate the accuracy of preoperative duplex scanning in patients with varicose vein. METHODS: Patients with primary varicose veins were retrospectively investigated. Diameters and reflux of PVs were evaluated before surgery with color flow duplex ultrasound scan (US). During operation, the incompetent PVs were defined as those that showed an outward spurt of blood flow from the stump of the PVs. The sensitivity and specificity of US in the detection of reflux of PVs were calculated. Competent versus incompetent vein diameters were compared with the Student t test and one-way analysis of variance. RESULTS: Three hundred twenty-four calf PVs were detected in 304 legs of 175 patients with varicose vein. Diameters of competent and incompetent PVs confirmed with intraoperative finding averaged 2.67 +/- 1.10 mm (n = 28) and 3.28 +/- 1.01 mm (n = 58), respectively, at the upper calf (P =.012), 2.85 +/- 0.85 mm (n = 53) and 3.68 +/- 0.94 mm (n = 137), respectively, at the lower calf (p <.001), and 2.67 +/- 0.99 mm (n = 14) and 3.27 +/- 0.66 mm (n = 22), respectively, at the posterior calf (P =.036). The overall sensitivity of detection of reflux with US was 87.7%, and the specificity was 75.3%. Diameters of true-incompetent PVs and false-incompetent PVs were 3.59 +/- 0.94 mm (n = 199) and 3.31 +/- 0.84 mm (n = 24), respectively (P =.157). Diameters of true-competent PVs and false-competent PVs were 2.61 +/- 0.91 mm (n = 73) and 2.89 +/- 0.82 mm (n = 28), respectively (P =.158). CONCLUSION: Although the diameter of incompetent PVs was larger than that of competent PVs in both US and intraoperative findings, diameter measurement alone can not completely distinguish competent and incompetent PVs. The sensitivity and specificity of reflux obtained with US showed that the accuracy of preoperative duplex scanning to evaluate PV competency was not sufficient.     

The sleep of Africans and Europeans in the Ivory Coast: questionnaire study

Sleep behaviour has been extensively studied with questionnaires in industrialised countries to investigate the epidemiology of sleep-wake disorders. However, only few attempts have yet been made to examine sleep behaviour of people living in Africa. Although, a large number of studies in hot or cold environments have used short-term exposures, reporting disrupted sleep for most of them, long-term exposures to stressful thermal environments are rare in the literature. Prior to the present investigation, we used questionnaires to analyse the effects of seasonal heat increase on perceived sleep behaviour and sleep quality in young native African students in Niger [7], even though these methods of investigation are by no means as accurate as polysomnographic recordings. The hypothesis was that sleep behaviour may be influenced by climatic variations in a hot dry tropical climate. Such climatic variations have been shown to induce seasonal heat acclimatisation marked by changes in body temperature rhythms in the hot versus the cool season [13]. Sleep behaviour was examined during two 7-day periods in January ("cool-dry" season, 88 subjects) and May ("hot-dry" season, 53 subjects). The questionnaire was completed after night sleep and/or naps. The subjects slept an average of 7 1/2 hours a day, most of them having afternoon naps. They experienced no major seasonal variation in their sleep behaviour, but for an increased number of awakenings during the hot season. Restorative quality of sleep scored lower after a nap than after nocturnal sleep. Therefore, general sleep characteristics were not modified by seasonal temperature variations in African native students, perhaps because of the limited changes in daylight under the low latitude of Niamey. Another investigation was carried out using the same 12-item questionnaire in Abidjan on 78 medical students who did not have a nap [9]. Contrary to the Niamey students, the Abidjan subjects adopted short duration sleep schedules, without any effect on the subjective quality of the restorative properties of their sleep.     

Inducible expression of FGF2 by a rat oligodendrocyte precursor cell line promotes CNS myelination in vitro

Transplantation of glial cells into the central nervous system (CNS) may be a promising approach for the treatment of myelin disorders such as multiple sclerosis (MS). Myelination by transplantation of oligodendrocyte precursors has been obtained in different animal models of demyelination. A strategy to favor CNS remyelination is to enrich the lesioned areas in growth factors to stimulate the quiescent population of oligodendrocyte precursors. In this context, we have developed a genetically modified CG4 cell line (CG4-FGF2), which are able to release significant amounts of fibroblast growth factor 2 (FGF2) in a controlable fashion in vitro. The data presented here demonstrate that upon induction with Dox, CG4-FGF2 cells retain their capacity to differentiate in vitro. Additionally, we provide evidence that FGF2 release by engineered cells enhance proliferation and migration of cells of the oligodendrocyte lineage without preventing them to differentiate and myelinate axons in vitro.     

Caries diagnosis using a laser fluorescence system--observation of autofluorescence of dental caries--

The purpose of this study was to evaluate the usefulness of autofluorescence of carious lesions on caries diagnosis. The observation of the micromorophology of caries lesions was conducted using a confocal laser scanning microscope, a fluorescence microscope and a WDX type electron probe X-ray microanalyzer. Observation of autofluorescence under Cy5 and UV fields showed clearly specific images of autofluorescence in the carious lesion. However, observation of autofluorescence under FITC field showed images of autofluorescence with unclear boundaries in the carious lesion. EPMA images showed decreases in Ca and P in the carious areas. As a result of the observation of autofluorescence and the EPMA images in the carious lesion, a correlation was noted between autofluorescence under the Cy5 field as the laser fluorescence apparatus for caries diagnosis and demineralized areas. The usefulness of autofluorescence of carious lesion on caries diagnosis was suggested.     

How surgeon age affects surveillance strategies for extremity soft tissue sarcoma patients after potentially curative treatment

BACKGROUND: The optimal strategy for follow-up of extremity soft tissue sarcoma patients after potentially curative treatment remains unknown. We investigated whether the date of completion of formal surgical training affects choice of surveillance strategy. MATERIALS AND METHODS: The 1,592 members of the Society of Surgical Oncology were asked how often they use 12 separate surveillance modalities during years 1-5 and 10 postsurgery. The motivation underlying follow-up was assessed separately. Repeated-measures analysis of variance was used to compare practice patterns by the year in which the surgeon's formal surgery training was completed, controlling for tumor grade, tumor size, and year postsurgery. RESULTS: Of the 716 respondents, 318 performed surgery and also provided long-term postoperative surveillance for their patients. These respondents were considered evaluable. Erythrocyte sedimentation rate, extremity X ray, and bone scan were the follow-up tests which differed significantly among physician age groups. Surgeons who completed training more than 30 years ago ordered erythrocyte sedimentation rate more frequently (P < 0.001). Surgeons in the 21-30 year category ordered extremity X ray and bone scan more frequently (P < 0.05), but the absolute differences among age groups were quite small. Older surgeons were also significantly more likely to believe that follow-up is clinically worthwhile. CONCLUSIONS: The posttreatment surveillance practice patterns of the members of the Society of Surgical Oncology caring for extremity soft tissue sarcoma patients vary only marginally with the length of time since completion of training. Postgraduate education may be one factor homogenizing surgeon behavior in this important aspect of cancer patient care.