Comprehensive survey of radionuclides in contemporary smokeless tobacco products

There is considerable interest in the chemical composition of smokeless tobacco products (STPs), owing to health concerns associated with their use. Previous studies have documented levels of 210Po, 210Pb and uranium in STP samples. Here, the levels of 13 α-particle and 15 β-radiation emitting radionuclides have been measured in a broad and representative range of contemporary STPs commercially available in the United States and Sweden. For each radionuclide, the level of radioactivity and calculated mass per gram of STP are reported. The results indicate that, among 34 Swedish snus and 44 US STPs, a more complex radionuclide content exists than previously reported for these products. Of the 28 radionuclides examined, 13 were detected and quantified in one or more STPs. The most frequently identified radionuclides in these STPs were 40K, 14C, 210Po and 226Ra. Over half the STPs also contained 228Th, and an additional 8 radionuclides were identified in a small number of STPs. The presence of 14C, 3H and 230Th are reported in tobacco for the first time. The activity of β-emitters was much greater than those of α-emitters, and the β-emitter 40K was present in the STPs with both the greatest radioactivity and mass concentrations. Since the three radionuclides included in the FDA's HPHC list were either not detected (235U), identified in only three of 78 samples (238U), and/or had activity levels over fifty times lower than that of 40K (210Po, 238U), there may be a rationale for reconsidering the radionuclides currently included in the FDA HPHC list, particularly with respect to 40K. Using a model of the physical and biological compartments which must be considered to estimate the exposure of STP users to radionuclides, we conclude that exposure from α-emitters may be minimal to STP users, but 40K in particular may expose the oral cavities of STP users to β-radiation. Although a more comprehensive picture of the radioisotope content of STPs has emerged from this study, epidemiological evidence suggests that the levels of radionuclides measured in this study appear unlikely to present significant risks to STP users.

Uranium and thorium sequential separation from norm samples by using a SIA system

This study presents a sequential radiochemical separation method for uranium and thorium isotopes using a novel Sequential Injection Analysis (SIA) system with an extraction chromatographic resin (UTEVA). After the separation, uranium and thorium isotopes have been quantified by using alpha-particle spectrometry. The developed method has been tested by analyzing an intercomparison sample (phosphogypsum sample) from International Atomic Energy Agency (IAEA) with better recoveries for uranium and thorium than the obtained by using a classical method (93% for uranium using the new methodology and 82% with the classical method, and in the case of thorium the recoveries were 70% for the semi-automated method and 60% for the classical strategy). Afterwards, the method was successfully applied to different Naturally Occurring Radioactive Material (NORM) samples, in particular sludge samples taken from a drinking water treatment plant (DWTP) and also sediment samples taken from an area of influence of the dicalcium phosphate (DCP) factory located close to the Ebro river reservoir in Flix (Catalonia). The obtained results have also been compared with the obtained by the classical method and from that comparison it has been demonstrated that the presented strategy is a good alternative to existing methods offering some advantages as minimization of sample handling, reduction of solvents volume and also an important reduction of the time per analysis.

Dolichos falcata Klein attenuated the inflammation induced by monosodium urate crystals in vivo and in vitro

ETHNOPHARMACOLOGICAL RELEVANCE

Dolichos falcata Klein (DF), a Chinese Dai ethnic medicine popularly known as "Tuoyeteng" in Yunnan province of China, has been widely used as a traditional herbal medicine for the treatment of fracture and beriberoid disease for a long time in China. The present study was carried out to investigate the anti-inflammatory activity and the bioactive chemical constituents of DF, and further to assess its possible mechanism on gouty arthritis in an animal model of the MSU crystals-induced gouty inflammation.

MATERIALS AND METHODS

The ethanol extract (EE) of DF at the doses of 10, 20 and 40 mg/kg was administered to the rats treated with MSU crystals to evaluate the anti-gouty arthritis effect. Subsequently, the components of EE were isolated and identified using classical methods. Phyto-chemical analysis of EE was further carried out by HPLC-DAD. Finally, the anti-inflammatory effect of EE and two isolated components were assessed using the MSU crystals-treated monocyte/macrophage cell line RAW 264.7 in vitro.

RESULTS

EE (10, 20 and 40 mg/kg) significantly attenuated the pain threshold value, the joint swelling degree, the inflammatory cell infiltration of articular tissue and the increased levels of pro-inflammatory cytokines in MSU crystals-treated rats. Moreover, doliroside A (DA) and medicagenic acid-3-O-β-D-glucopyranoside (MG) were isolated and identified from EE. The major components of EE, including DA, MG and other triterpenoids, were well confirmed by HPLC. A further study revealed that EE, DA and MG (10, 20, 40μg/mL) exhibited stronger inhibitory effects on the production of pro-inflammatory cytokines (including interleukin-1β, interleukin-6 and tumor necrosis factor-α) in MSU crystals-treated RAW 264.7 cells.

CONCLUSION

These findings indicate that the major triterpenoids present in DF have a remarkable effect on improving symptoms of acute gouty arthritis induced by MSU crystals through inhibiting the production of pro-inflammatory cytokines.

Exploring the genetic basis of stroke. Spanish stroke genetics consortium

This article provides an overview of stroke genetics studies ranging from the candidate gene approach to more recent studies by the genome wide association. It highlights the complexity of stroke owing to its different aetiopathogenic mechanisms, the difficulties in studying its genetic component, and the solutions provided to date. The study emphasises the importance of cooperation between the different centres, whether this takes places occasionally or through the creation of lasting consortiums. This strategy is currently essential to the completion of high-quality scientific studies that allow researchers to gain a better knowledge of the genetic component of stroke as it relates to aetiology, treatment, and prevention.

The histone acetyltransferase component TRRAP is targeted for destruction during the cell cycle

Chromosomes are dynamic structures that must be reversibly condensed and unfolded to accommodate mitotic division and chromosome segregation. Histone modifications are involved in the striking chromatin reconfiguration taking place during mitosis. However, the mechanisms that regulate activity and function of histone-modifying factors as cells enter and exit mitosis are poorly understood. Here, we show that the anaphase-promoting complex or cyclosome (APC/C) is involved in the mitotic turnover of TRRAP (TRansformation/tRanscription domain-Associated Protein), a common component of histone acetyltransferase (HAT) complexes, and that the pre-mitotic degradation of TRRAP is mediated by the APC/C ubiquitin ligase activators Cdc20 and Cdh1. Ectopic expression of both Cdh1 and Cdc20 reduced the levels of coexpressed TRRAP protein and induced its ubiquitination. TRRAP overexpression or stabilization induces multiple mitotic defects, including lagging chromosomes, chromosome bridges and multipolar spindles. In addition, lack of sister chromatid cohesion and impaired chromosome condensation were found after TRRAP overexpression or stabilization. By using a truncated form of TRRAP, we show that mitotic delay is associated with a global histone H4 hyperacetylation induced by TRRAP overexpression. These results demonstrate that the chromatin modifier TRRAP is targeted for destruction in a cell cycle-dependent fashion. They also suggest that degradation of TRRAP by the APC/C is necessary for a proper condensation of chromatin and proper chromosome segregation. Chromatin compaction mediated by histone modifiers may represent a fundamental arm for APC/C orchestration of the mitotic machinery.

Comparative study of different analytical methods for the determination of 238U, 234U, 235U, 230Th and 232Th in NORM samples (Southern Catalonia)

Uranium and thorium isotopes from sludge samples taken from an area of influence of a dicalcium phosphate factory, located close to the Ebro River reservoir in Flix, and from mineral raw materials (coal and phosphate) which were deposited in Tarragona Harbour (Catalonia) have been measured. To do that, several procedures to determine these isotopes have been applied and compared in terms of accuracy, precision and total analysis time. In particular, digestion procedures, such as one based on conventional acidic digestion or another based on the use of microwave digestion, have been tested. Moreover, different radiochemical separation procedures have been applied. In this regard, one method based on liquid-liquid extraction using TBP/Xylene and another based on the use of extraction chromatography using UTEVA resins have been compared. Firstly, the different proposed methods were tested by analyzing a phosphogypsum sediment and a moss-soil sample from two different intercomparison exercises. The microwave digestion - UTEVA method provided the best results (recoveries higher than 82% for uranium and thorium isotopes) and was then applied to the NORM samples. The obtained results showed that the higher uranium and thorium activities values were found in phosphate raw material and in the more superficial samples located in sludge sediments next to the dicalcium phosphate factory.

Distribution of naturally occurring radioactive materials in sediments from the Ebro river reservoir in Flix (Southern Catalonia, Spain)

Industrial waste containing radioactive isotopes (from U-decay series) was released into Ebro river basin due to the activity of a dicalcium phosphate (DCP) plant for a period of more than two decades. Gross alpha, gross beta, (40)K, (226)Ra and (210)Pb activities were determined in several sludge samples taken at different depths from different points in the area of influence of the DCP plant located in Flix. Samples were collected from two different zones: one in front of the DCP plant and the second in front of a wastewater treatment plant installed several years after the DCP plant. The data obtained verify the influence of industrial DCP production on radioactivity levels present in the area.

Surgery of thyroid cancer: twelve years' personal experience

Diagnosis and treatment of thyroid carcinoma require a multidisciplinary approach. The close and long-standing collaboration between the Otorhinolaryngology, Pathological Anatomy and Nuclear Medicine Departments of Legnano Hospital has led to a precise diagnostic and therapeutic protocol in thyroid patients. In the 1990-2002 period, 131 patients underwent total thyroidectomy after diagnosis of thyroid cancer at the Otorhinolaryngology--Head and Neck Surgery Department. Patients submitted to lobectomy for differentiated thyroid cancer were excluded from the present study. The patient population is composed of 96 females (73%) and 36 males (27%) aged between 22 and 85 years. Of the 131 patients, 115 (87%) presented papillary carcinoma, 13 (10%) follicular carcinoma, 2 (2%) medullary carcinoma and one (1%) undifferentiated carcinoma. Two patients (2%) suffered from a preoperative monolateral recurrent nerve palsy. Total thyroidectomy was performed in all 131 patients. Selective neck dissection was performed only in patients with positive lymph nodes for papillary (37/115, 32%) and follicular carcinoma histotype (2/13, 15%) and, in both patients with medullary carcinoma (100%). Of the 131 patients, 15 (11%) did not undergo routine follow-up and were, therefore, excluded from the study, the remainder completed a mean follow-up of 47 months. During follow-up, the incidence of the two most frequent complications of thyroid surgery were evaluated: recurrent nerve paralysis and permanent hypoparathyroidism (exceeding the postoperative 6 months). Results of treatment have been evaluated considering the incidence of local and/or distant recurrences and patient survival rate. As far as concerns papillary and follicular histotype, we have considered as healed (absence of signs suggesting loco regional and distant recurrence) only those patients presenting both negligible levels of plasma thyroglobulin and a negative total-body 131I scintigraphy. Briefly, in 3 cases (3%), all papillary carcinomas, local recurrence occurred; 9 (8%), all with papillary carcinoma, developed lateral neck recurrence; 6 (5%), 5 with papillary carcinoma and one with follicular carcinoma, developed distant metastases, of which 3 pulmonary, 2 bone and 1 hepatic. Serum thyroglobulin values were considered during the last control visit in 95/113 patients (84%). Of these, 86 (91%) with negligible thyroglobulin levels and negative 131I scintigraphy, were considered healed. All 113 patients with differentiated thyroid carcinoma were alive at the last control visit. Both patients with medullary carcinoma are alive with no sign of illness at the last follow-up control. The patient presenting undifferentiated carcinoma died 2 months after surgery. In conclusion, at the last follow-up control, 1 (1%) patient has died, 5 patients (4%) are alive with disease (2 of whom suffered from multiple recurrences) and the remaining 110 (95%) patients are alive without evidence of disease. As far as concerns complications of surgery, iatrogenic recurrent palsy and permanent hypoparathyroidism are present in 2 (2%) and 10 patients (8%), respectively.

Role of EEG monitoring and cross-clamping duration in carotid endarterectomy

The usefulness of electroencephalographic (EEG) monitoring as well as the significance of the period of cross clamping in carotid endarterectomy have not been completely defined. In particular, the clinical importance of major EEG changes has not been fully investigated and some recent studies seem to indicate that the method has little value. As to the duration of cross clamping, there is strong evidence that occlusion times of about 15 minutes are tolerated under general anesthesia, but no information is available regarding longer periods of occlusion. The authors describe a consecutive series of 141 carotid endarterectomies in which the patients with EEG changes were shunted only when occlusion was anticipated to last longer than 30 minutes. Early major EEG changes (during the first 4 minutes) occurred in 14% of the cases. In the absence of EEG changes, long occlusion periods of 40 to 50 minutes were well tolerated. In contrast, the 20 patients with major persistent EEG changes did not tolerate protracted occlusion and three of them had immediate postoperative neurological complications. It seems that, in these circumstances, the incidence of neurological deficit is a function of the duration of cross clamping: these three patients had undergone occlusion for 15 to 30 minutes. Their deficits partially resolved. On the basis of these results it is concluded that: EEG recording is a reliable monitoring system in carotid artery cross clamping. No major strokes due to temporary carotid artery occurred in the series. The clinical significance of major persistent EEG changes is not negligible. Cross clamping for longer than 15 minutes in the presence of significant EEG alterations is potentially dangerous.

Continuous intraoperative electroencephalographic monitoring in carotid endarterectomy

Continuous electroencephalographic (EEG) monitoring was done during 143 consecutive carotid endarterectomies in 130 patients to detect intolerance to cross-clamping. An intraluminal shunt was inserted when EEG changes appeared (in the first 100 procedures) or when EEG changes appeared and a long clamping time was supposed (in the last 43 cases). 121 patients had no EEG changes at clamping time and only 1 had a postoperative deficit due to embolization, which occurred before clamping and was revealed by a decrease of voltage on tracing. 15 patients showed early (within 4 min after clamping) changes and in 11 patients shunting led to the reversal of EEG anomalies in all cases but 2. The state of these 2 patients was worse after surgery, in one because of embolic problems, in the other (shunted 30 min after clamping) probably for hemodynamic reasons. 4 patients with early EEG changes, not shunted because of the short clamping time, had no neurological deficit. 7 patients, 2 of which were shunted, showed late (after 4 min) EEG changes. Only 1 nonshunted patient in this group awoke with a minor, transitory neurological complication. Moreover, EEG changes have been correlated with the preoperative clinical condition and with the presence, on angiography, of contralateral carotid lesions. Also, EEG findings have been correlated with the computed tomography data (in 71 cases) and with the values of interior carotid artery (ICA) back pressure (in 58 cases). No possibility to predict the tolerance to clamping appeared from these correlations. However, a relatively higher risk of intolerance to clamping in patients with contralateral ICA occlusion was noted.(ABSTRACT TRUNCATED AT 250 WORDS)

Platelet immune complex interaction in pathogenesis of Kawasaki disease and childhood polyarteritis

The role of platelets in the pathogenesis of vasculitis and the formation of coronary artery aneurysms was studied in 19 children with Kawasaki disease and five with polyarteritis. All patients with Kawasaki disease developed thrombocytosis in the third week of illness. The peak platelet count was significantly correlated (p less than 0.005) with the subsequent development of coronary artery aneurysms. The rise in platelet count was associated with the appearance in the circulation of a factor that induced aggregation and serotonin release in normal platelets. This factor was shown to be of high molecular weight, and its activity was lost at low pH--features suggestive of an immune complex. Immune complexes, detected by precipitation with polyethylene glycol, also appeared in the circulation as the platelet count increased. These complexes induced platelet aggregation, and there was a significant correlation (p less than 0.001) between the concentrations of IgG and IgA in the polyethylene glycol precipitated material and the platelet aggregating activity. Similar platelet aggregating activity was also detected in patients with polyarteritis but followed a different time course, persisting in the circulation for several months in association with continued disease activity. These findings imply that different mechanisms have a role in distinct phases of Kawasaki disease. The initial feverish phase (probably infective) is probably followed by an immune complex vasculitis that occurs when antibodies to the initiating agent appear in the circulation. The immune complexes aggregate platelets and induce release of serotonin. Platelet derived vasoactive mediators may increase vascular permeability and facilitate further deposition of complexes in the tissues.

EEG findings in 118 cases of myasthenia gravis

We examined 148 EEG recordings from 118 patients affected with myasthenia gravis (35 males and 83 females, aged 17-82, with illness durations between 1 month and 24 years). The cases were clinically evaluated according to Ossermann's classification at the time of EEG recording. EEG patterns were subdivided into normal, diffuse or focal slow abnormalities, or epileptiform patterns. Of the 118 patients, 104 had normal EEG recordings and 14 had at least one abnormal recording (8 diffuse slow abnormalities, 6 focal slow abnormalities). The EEG findings were not correlated with clinical parameters (thymic pathology, respiratory incidents, drug treatment, etc.). One patient (whose EEG recordings were normal) showed an isolated epileptic fit and another patient was affected by epilepsy. A possible relationship between the two diseases is discussed.