Biological dust exposure in the workplace is a risk factor for chronic obstructive pulmonary disease

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity and mortality. Although the main risk factor is smoking, 15-19% of COPD even in smokers has been attributed to occupational exposures. The aim of this study was to investigate the association between occupational exposure and risk of COPD. METHODS: Participants were part of a cross sectional study of risk factors for COPD. A total of 1232 completed a detailed respiratory questionnaire, spirometric testing and measurement of gas transfer. Job histories were coded according to the International Standard Classification of Occupations. These codes were then used to establish occupational exposures using the ALOHA job exposure matrix. RESULTS: The prevalence of emphysema was 2.4%, chronic obstructive bronchitis 1.8%, and COPD 3.4%. Subjects ever exposed to biological dusts had an increased risk of chronic obstructive bronchitis (OR 3.19; 95% CI 1.27 to 7.97), emphysema (OR 3.18; 95% CI 1.41 to 7.13), and COPD (OR 2.70, 95% CI 1.39 to 5.23). These risks were higher in women than in men. For biological dust, the risk of emphysema and COPD was also significantly increased in both the duration of exposure categories, again in women but not in men. No significant increased risks for COPD were found for mineral dust (OR 1.13; 95% CI 0.57 to 2.27) or gases/fumes (OR 1.63; 95% CI 0.83 to 3.22). CONCLUSION: In this general population sample of adults, occupational exposures to biological dusts were associated with an increased risk of COPD which was higher in women. Preventive strategies should be aimed at reducing exposure to these agents in the workplace.     

Remifentanil for sedation and analgesia in a preterm neonate with respiratory distress syndrome

We present the efficacy and safety of the use of remifentanil for intubation, sedation and analgesia in a preterm infant during mechanical ventilation for respiratory distress syndrome. A 34-week-old baby, born by cesarean delivery that developed respiratory distress, required intubation and ventilatory support. For intubation, the baby was given midazolam (0.2 mg.kg(-1)) and remifentanil (1 microg.kg(-1)). The intubation conditions were assessed and classified as excellent. The remifentanil infusion was started at dose 0.75 microg.kg(-1).min(-1) and the dose adjustments were made depending on the neonatal infant pain scale (NIPS), hemodynamic and respiratory changes or the presence of spontaneous movements. Pulse oximetry, respiratory rate, ECG and invasive blood pressure were continuously monitored. He was given surfactant within 2.5 h of life after which ventilator parameters could be progressively decreased. Three hours later, the remifentanil infusion was decreased to 0.5 microg.kg(-1).min(-1), and he remained sedated (NIPS < 2). Six hour after surfactant administration, blood gases and chest X ray were normal. The remifentanil infusion was then discontinued and 30 min later the baby was awake and extubated with success. There were no side effects after intubation or during the continuous infusion. The profile of remifentanil allowing a rapid recovery, the absence of side effects and a good level of sedation and analgesia support the choice of this opioid for sedation in the NICU.     

Transformation of adult mesenchymal stem cells isolated from the fatty tissue into cardiomyocytes

BACKGROUND: Myocardial infarction results in the death of cardiomyocytes, which are replaced by scar tissue. Cardiomyocytes cannot regenerate because they are terminally differentiated. Mesenchymal cells are pluripotent cells, which have the potential to differentiate to specialized tissues under appropriate stimuli. The aim of this study was to direct differentiation of the adult mesenchymal stem cells isolated from fatty tissue into cardiomyocytes using 5-azacytidine. METHODS: Adult mesenchymal stem cells were isolated from the fatty tissue of New Zealand White rabbits and cultured in RPMI medium. Second-passaged mesenchymal cells were treated with various concentrations of 5-azacytidine and incubated for different intervals of time. The cells were plated in six-well dishes at 500, 5,000, and 50,000 cells/well. These cells were treated with 1-, 3-, 6-, 9-, and 12-micromol/L concentrations of 5-azacytidine and incubated for 12, 24, 48, and 72 hours. Later, the medium was replaced with fresh medium and incubated in a CO2 incubator. The medium was changed once at 3 to 4 days. At 2 months, the cells were fixed with 0.4% glutaraldehyde for 2 hours and later washed with phosphate-buffered saline. The transformed cells were subjected to immunostaining for the myosin heavy chain, alpha actinin, and troponin-I. RESULTS: After treatment with 5-azacytidine, the adult mesenchymal stem cells were transformed into cardiomyocytes. At 1 week, some cells showed binucleation and extended cytoplasmic processes with adjacent cells. At 2 weeks, 20% to 30% of the cells increased in size and formed a ball-like appearance. At 3 weeks, these cells began to beat spontaneously in culture when observed under phase contrast microscope. Immunostaining of the transformed cells for myosin heavy chain, alpha actinin, and troponin-I was positive. The differentiated cells maintained the phenotype and did not dedifferentiate up to 2 months after treatment with 5-azacytidine. CONCLUSIONS: These observations confirm that adult mesenchymal stem cells isolated from fatty tissue can be chemically transformed into cardiomyocytes. This can potentially be a source of autologous cells for myocardial repair.     

Bowel and bladder function after major sacral resection

Major sacral resection generally is reserved for patients with malignant lesions. Because of the uncommon nature of these diseases, little is known about outcomes of surgical treatment. The current authors describe the retrospective analysis of bowel and bladder function in patients having major sacral resection at their institution during a 10-year period. Fifty-three patients were identified. In patients who had unilateral sacrectomy, in whom the contralateral sacral nerves were preserved, normal bowel and bladder function was retained in 87% and 89%, respectively. In patients who had bilateral S2-S5 nerve roots sacrificed, all had abnormal bowel and bladder function. In patients who had bilateral S3-S5 resection, normal bowel and bladder function was retained in 40% and 25%, respectively. In patients who had bilateral S4-S5 resection, with preservation of the S3 nerves bilaterally, normal bowel and bladder function was retained in 100% and 69%, respectively. In patients who had asymmetric sacral resections, with preservation of at least one S3 nerve root, normal bowel and bladder function was retained in 67% and 60%, respectively. These results show that unilateral resection of sacral roots or preservation of at least one S3 root in bilateral resection preserves bowel and bladder function in the majority of patients.     

Relationship between surgical margins and local recurrence in sarcomas of the spine

The combination of improved resection, stabilization, and fusion techniques allows for more aggressive removal of malignant spinal tumors with acceptable mortality and morbidity. Thirty consecutive patients with primary sarcomas of the mobile spine, who were operated on at the authors' institution from January 1970 to December 2000, were included in the current study. Demographic information, tumor location, type of resection, resection margins, local recurrence, and overall survival data were retrieved and analyzed. Treatment consisted of en bloc resection in 12 patients (40%) and piecemeal resections in 18 patients (60%). The resection was classified as wide in seven patients (23.3%), marginal in three patients (10%), and intralesional in 20 patients (66.7%). Pathology reports showed tumor-free resection margins in 12 patients (40%). In the remaining 18 patients (60%), resection margins were positive and resulted in a fivefold increase in the risk of a local recurrence. Ninety-two percent of the patients with local recurrence died of sequelae associated with the local recurrence. Primary sarcomas of the mobile spine in certain cases, can be removed completely with tumor-free resection margins. En bloc resection with tumor-free margins provides substantial improvement in overall survival.     

Intrathecal carbachol and clonidine produce a synergistic antiallodynic effect in rats with a nerve ligation injury

PURPOSE: Antiallodynic effects have been demonstrated after intrathecal administration of alpha-2 adrenoceptor agonists and cholinesterase inhibitors in rats. Intrathecal carbachol also increases the activity of cholinergic receptor system at the spinal level. However, there is no study regarding the antagonism of carbachol on touch-evoked allodynia and the interaction with clonidine. This study examines the intrathecal interaction between two drugs in a rat model of nerve ligation injury. METHODS: Rats were prepared with tight ligation of the left L5-6 spinal nerves and chronic intrathecal catheter implantation. Tactile allodynia was measured by using application of von Frey filaments to the lesioned hindpaw. Carbachol (0.3-10 microg) and clonidine (1-30 microg) were administered to obtain the dose-response curves and the 50% effective dose (ED(50)) for each drug. Fractions of ED(50) values (1/2, 1/4, 1/8, and 1/16) were administered intrathecally to establish the ED(50) of the carbachol-clonidine combination. Isobolographic and fractional analyses of drug interaction were performed. RESULTS: Intrathecal carbachol and clonidine alone produced a dose-dependent reduction of tactile allodynia without severe motor weakness or sedation. A carbachol-clonidine combination produced a dose-dependent increase in withdrawal threshold of the lesioned hindpaw with a reduced incidence and magnitude of side effects. Both analyses revealed a synergistic interaction after the coadministration of carbachol and clonidine. CONCLUSIONS: This study indicates that carbachol, like clonidine, provides a moderate antagonism on touch-evoked allodynia at the spinal level. The results suggest that intrathecally administered carbachol is synergistic when combined with clonidine.     

Long-term results of endoscopic treatment of vesicoureteral reflux with the sub-ureteric injection of calcium hydroxyapatite

Aim To review our long-term results of the sub-ureteric injection of calcium hydroxyapatite in the endoscopic management of vesicoureteral reflux (VUR) in children. Materials and methods A sub-ureteric injection of calcium hydroxyapatite was given to 14 children (23 ureteral units) affected by VUR grades I–V. All children were followed-up with monthly urine cultures, and a renal ultrasound was done on the postoperative 4th week, while the first voiding cysto-urethrogram (VCUG) control was performed on postoperative week 12. The children were followed-up with yearly renal ultrasound and monthly urine cultures, thereafter. Data from the patients’ charts were retrospectively analyzed regarding the outcome of the procedures. Results Mean follow-up time was 52 months (47–60 months). VUR was cured in 47.4% of cases after a single injection. After the second injection the global success rate was 52.1%. Ureteroneocystostomy was performed on seven refluxing ureters of five children unresponsive to sub-ureteric injection therapy. One patient underwent nephroureterectomy because of a non-functioning kidney secondary to ureteral obstruction due to migration of material at the 23rd month postoperatively. Conclusion Although favorable short-term success rates have been reported with the sub-ureteric injection of calcium hydroxyapatite without any side effects, our long-term results showed a low success rate, with the only reported serious morbidity.     

Effects of hyperbaric oxygen therapy on the rat intestinal mucosa apoptosis caused by ischemia-reperfusion injury

To examine the apoptosis expression in the intestinal mucosa in accordance of different periods of hyperbaric oxygen (HBO) treatment, rats were submitted to 60 min of mesenteric artery and vein ischemia and 60 min of reperfusion occlusion. A group (G-IR) was the control and HBO was applied in the ischemia (GHBO-I), reperfusion (GHBO-R), and ischemia and reperfusion time (GHBO-IR). After 60 min of reperfusion, samples of small bowel were prepared for immunohistochemical expression of caspase-3. The expression of caspase-3 was significantly inferior when HBO was administered in the ischemia (0.16 +/- 0.01) in comparison with the control (0.70 +/- 0.08), but HBO in the further reperfusion (0.84 +/- 0.03) or both ischemia and reperfusion time (0.42 +/- 0.05) was significantly worse. There was a connection between HBO, small bowel I/R injury, and mucosa apoptosis. The favorable effect was obtained when HBO was administered early in the ischemia time.     

Cytokine expression in the renal tubular epithelial cells stimulated by Shiga toxin 2 of Escherichia coli O157:H7

Hemolytic uremic syndrome (HUS) is the most common cause of acute renal failure in children worldwide. Shiga toxin (Stx) associated HUS, the most common type, is now known to be caused by Escherichia coli O157:7, which produces Stxl or the more potent, Stx2. Since the renal tubule is the major tissue affected in the course of HUS and Stx2 is known to be toxic to the renal tubular cells (RTC), we attempted to elucidate the mechanism of renal injury in HUS by studying the alteration of cytokines in the RTC evoked by Stx2. cDNA-array is a powerful tool for evaluating changes in the expression of a group of critical genes and also gives insights on the overview of the gene activation. In this study, we purified Stx2 from the E. coli O157:7, which was isolated from a typical diarrhea-associated HUS patient and then tried to compare the cytokine gene expression between the stimulated RTC and un-stimulated RTC using cDNA-array. Our results showed that one third of the examined cytokine genes were up regulated at least twice by the addition of Vtx2. These up-regulated genes represented the chemokines (macrophage related cytokines), fibrosis-related cytokine (TNF, PDGF) and leukemia inhibitory factors. However, the expression of IL-6, one of the pleiotropic cytokines, was significantly decreased and this finding was confirmed by northern analysis. Our results suggest that VT2 up-regulates the pro-inflammatory cytokines and fibrosis prone growth factors in RTC and that the inhibition of the activation of these cytokines may ameliorate the renal tubular injury in the HUS caused by E. coli O157:7.