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PubMed2003

Mesotheliomas among Italians, returned to the home country, who worked when migrant at a cement-asbestos factory in Switzerland.

OBJECTIVES: To report the occurrence of mesotheliomas in Italy among subjects who worked, when migrant, at a cement-asbestos factory in Niederurnen, Switzerland, and had resettled to the home country. METHODS: Information about the disease and on the working history of subjects was collected by regional mesothelioma registries. Only cases diagnosed by means of histo-pathological examinations have been considered here. RESULTS: 15 mesotheliomas (13 pleural, 2 perithoneal; 12 among males, 3 among females) have been identified among Italians, who had worked at the factory. None of them had other occupational exposure to asbestos. The majority was living in the Veneto Region (North East of Italy), and in Puglia (Southern Italy). CONCLUSIONS: Exposure to asbestos at this factory has already caused an important number of occupational cancers among the employees, a large fraction being constituted of migrants. In order to avoid under-estimation of risks and to allow compensation, diseases which occur among foreign workers returned to their home country should be evaluated. Migration for work is at the genesis of asbestos-related mesotheliomas now occurring in Italy.

Adult↗
PubMed1990

The Pacific eulachon (Thaleichthys pacificus) as a pollution indicator organism in the Fraser River estuary, Vancouver, British Columbia.

Eulachons return to the Fraser River each spring and migrate through the estuary to spawn in freshwater. During this migration they may be subjected to varying water quality conditions due to the discharge of domestic and industrial wastes and land drainage. Fish were captured at five estuarine stations in April 1986 and again at three stations in April/May 1988. The locations were from Steveston, at the river mouth, to Port Mann bridge, 31.0 km upstream, just above saltwater influence. Water samples, whole fish, gonads and pooled livers of both sexes were analyzed separately for selected organochlorine contaminants. Water and tissue samples contained chlorophenols from wood preservation operations and chloroguaiacols from pulp bleaching. Whole fish also contained DDE and DDD, while PCBs were present in some fish gonads in 1986, but not in 1988. With the exception of whole body concentrations of 2,3,4,6-tetrachlorophenol (TeCP), concentrations of pentachlorophenol (PCP), 3,4,5-trichloroguaiacol (3,4,5-TCG), tetrachloroguaiacol (TeCG), DDE and DDD in whole bodies, livers and gonads revealed an increasing trend with distance of the eulachon capture site upstream from the Fraser River mouth. Marked differences occurred in the concentration of contaminants in eulachon livers (for example, levels of 50.8 +/- 42.2 ng g-1 3,4,5-TCG at Steveston, and 446.4 +/- 222.5 ng g-1 at Port Mann). The relatively high lipid content of eulachons suggests them to be potential integrators of low-level contaminants in the Fraser River system. This, and their anadromous life history, recommend them as suitable annual monitors of selected organic compounds.

Animals↗
PubMed2003

Modelling the environmental fate of the polybrominated diphenyl ethers.

In response to growing alarm over the occurrence of polybrominated diphenyl ethers (PBDEs) in remote regions, this study considers their physical chemistry, environmental partitioning and considerations regarding potential for long-range atmospheric transport (LRAT). Internally consistent physical-chemical property data are presented for five representative congeners (PBDE-15, -28, -47, -99, -153) and used in a multimedia modelling approach. Results of the Level II model indicate that PBDEs will largely partition to organic carbon in soil and sediment and that their persistence will be strongly influenced by degradation rates in these media that are not well known. TaPL3 model estimates of their characteristic travel distance (CTD) suggest limited LRAT potential. The LRAT is also evaluated qualitatively, in terms of surface-air exchange behaviour. PBDEs are shown to be sensitive to seasonally and diurnally fluctuating temperatures. When vegetation is included in the model, 50% of the total mass of PBDE-47 deposited to vegetation returns to the atmosphere, suggesting that it may migrate through a series of deposition/volatilisation hops. Key data that needs to be identified in this evaluation include a better understanding of air-surface exchange, particularly to foliage, and measurements of degradation rates in soil, sediment and vegetation.

Atmosphere↗
PubMed1993

Bipolar socket in protrusio acetabuli. 3-6-year study.

Twenty-two hips with protrusio acetabular deformity in 14 patients received bipolar socket hemiarthroplasty combined with bone-grafting to the medial wall defect. The surgical technique included crushed cancellous grafting and attention to adequate rim contact for the socket. Results were evaluated at a mean of 54 months after surgery (range, 36-76 months). On hip had thigh pain attributable to a loose femoral component. No patient had groin pain at follow-up examination. A satisfactory range of motion was achieved in all but one case, and an average increase of 40 points in the Harris hip score was realized. Radiographically, all acetabuli were returned to a more normal, inferolateral position. Socket migration (measured relative to the teardrop) in the range of 3-7 mm was noted in 5 hips; the remaining 17 hips displayed no or minimal migration of the socket (< 3 mm). The bipolar socket with crushed cancellous graft appears to be an acceptable surgical alternative in protrusio acetabuli, providing a reliable relief of pain, satisfactory functional results, and a restoration of acetabular bone stock in the majority of cases.

Acetabulum↗
PubMedDate not supplied

Determination of epidural catheter placement using nerve stimulation in obstetric patients.

BACKGROUND AND OBJECTIVES: Peripheral nerve and spinal cord stimulation techniques have been used for many years. However, electrical stimulation methods rarely have been used to confirm epidural catheter placement. This study examines the practicality of this technique to confirm epidural catheter placement in obstetric patients. METHODS: Thirty-nine obstetric patients in labor were studied. An electrocardiography (ECG) adapter (Arrow-Johans) was attached to the proximal end of the epidural catheter (19-gauge Arrow Flextip plus). Then, the lowest milliamperage (1-10 mA) necessary to produce a motor response (truncal or limb movement) was applied using this setup. A positive motor response indicated that the catheter was in the epidural space. This test was performed initially after catheter insertion and repeatedly after incremental local anesthetic doses. RESULTS: The sensitivity and specificity of the new test was 100% and 100%, respectively, with 38 true positive tests and 1 true negative test. The threshold current required to produce a positive test increased after incremental doses of local anesthetic. A case of intravascular epidural catheter migration was detected using this new test. In this case, the patient's increased threshold milliamperage returned to the baseline value within 1 hour, despite having received local anesthetic. Intravascular epidural catheter migration was subsequently confirmed by a positive epinephrine test dose. Thus, this test appears to be a potentially useful method to detect intravascular catheter placement. CONCLUSION: This study demonstrates that this test may have a role in improving the success rate of epidural anesthesia.

Anesthesia, Epidural↗
PubMed1985

The influence of a chronic subclinical infection of Trichostrongylus colubriformis on gastrointestinal motility and digesta flow in sheep.

The influence of a chronic subclinical infection of Trichostrongylus colubriformis, 2500 larvae/day for 12 weeks, on gastrointestinal motility and digesta flow was studied in 12 sheep supplied ad libitum with food and water. Motility was recorded by X-radiography and electromyography from chronically implanted electrodes; abomasal volume and outflow were estimated by dilution of CrEDTA; small intestinal transit time was estimated by passage of Phenol Red. The findings were compared with measurements made prior to infection at restricted food intake and reported separately. The first effects of infection were seen after 3-4 weeks. No animal developed diarrhoea, but food intake was progressively reduced. Small intestinal transit time, abomasal volume and half-time of marker dilution increased while abomasal outflow decreased during infection. These changes occurred both in absolute terms and when compared with values predicted from the observed level of food intake. As the animals became resistant to the parasites abomasal volume and digesta flow returned towards control values (weeks 10-12). The migrating myoelectric complex (MMC) was disrupted in only one sheep, and only transiently. In all sheep the frequency of the MMC was increased during infection and there was a progressive inhibition of abomasal, duodenal and jejunal motility. X-radiography showed there was prolonged pooling of digesta in the proximal small intestine which was cleared only at the phase of regular spiking activity. Two sheep given an anthelmintic drench recovered normal motility and clearance of digesta. It is concluded that subclinical infection of sheep with T. colubriformis alters the normal pattern of gastrointestinal motility in the absence of any diarrhoea, and causes inhibition of abomasal and proximal small intestinal motility and digesta flow. The increased frequency of MMCs helps to maintain digesta flow through the proximal small intestine.

Abomasum↗
PubMed2003

Copper(I) chloride initiated decomposition of 7-phosphanorbornadiene. Evidence for a solvent-assisted catalytic mechanism.

Density functional theory is used to explore the mechanism of the copper(I)-chloride-catalyzed decomposition of W(CO)(5)-complexed 7-phosphanorbornadiene and the subsequent olefin trapping of the terminal phosphinidene complex. CuCl lowers the activation barrier by interacting directly with the breaking P-C bond. Contrary to the prevailing notion that a free terminal phosphinidene complex (W(CO)(5)=PR) is generated in the CuCl-catalyzed cheletropic elimination of the 7-phosphanorbornadiene-W(CO)(5) complex, the present mechanism suggests that CuCl is attached to the terminal phosphinidene. Furthermore, a "chloride shuttle" takes place where the chloride first migrates to the phosphorus center and then is returned back to the copper center by the incoming olefin in an S(N)2 reaction step. When the substituent on phosphorus is a phenyl group (R = Ph), the uncatalyzed reaction has an activation barrier of 17.9 kcal/mol, which is reduced by 10.9 kcal/mol on including the CuCl catalyst. The CuCl-catalyzed decomposition of 7-phosphanorbornadiene followed by olefin trapping of the terminal phosphinidene complex has a close parallel with the Cu(I)-catalyzed cyclopropanation reaction of diazoalkane. In both catalyzed reactions, copper(I) is coordinated to the phosphinidene/carbene as a Lewis acid, while a Lewis base is displaced from the phosphorus/carbon center as the olefin is added.

Journal Article↗
PubMed2005

The position 68(E11) side chain in myoglobin regulates ligand capture, bond formation with heme iron, and internal movement into the xenon cavities.

After photodissociation, ligand rebinding to myoglobin exhibits complex kinetic patterns associated with multiple first-order geminate recombination processes occurring within the protein and a simpler bimolecular phase representing second-order ligand rebinding from the solvent. A smooth transition from cryogenic-like to solution phase properties can be obtained by using a combination of sol-gel encapsulation, addition of glycerol as a bathing medium, and temperature tuning (-15 --> 65 degrees C). This approach was applied to a series of double mutants, myoglobin CO (H64L/V68X, where X = Ala, Val, Leu, Asn, and Phe), which were designed to examine the contributions of the position 68(E11) side chain to the appearance and disappearance of internal rebinding phases in the absence of steric and polar interactions with the distal histidine. Based on the effects of viscosity, temperature, and the stereochemistry of the E11 side chain, the three major phases, B --> A, C --> A, and D --> A, can be assigned, respectively, to ligand rebinding from the following: (i) the distal heme pocket, (ii) the xenon cavities prior to large amplitude side chain conformational relaxation, and (iii) the xenon cavities after significant conformational relaxation of the position 68(E11) side chain. The relative amplitudes of the B --> A and C --> A phases depend markedly on the size and shape of the E11 side chain, which regulates sterically both ligand return to the heme iron atom and ligand migration to the xenon cavities. The internal xenon cavities provide a transient docking site that allows side chain relaxations and the entry of water into the vacated distal pocket, which in turn slows ligand recombination markedly.

Animals↗
PubMed2002

A technique for safe placement of a biliary endoprosthesis after laparoscopic choledochotomy.

BACKGROUND: Biliary endoprosthesis has been proposed as an alternative to T-tube placement after laparoscopic choledochotomy in an attempt to eliminate the complications associated with T-tubes. Biliary endoprostheses have been, until now, placed under fluoroscopic guidance. We present a modification of Gersin's method for endoprosthesis placement under direct vision. PATIENTS AND METHODS: As of July 2001, seven patients who fulfilled the criteria for common bile duct (CBD) exploration through a choledochotomy, a biliary endoprosthesis was inserted under direct vision at the end of the procedure with primary closure of the CBD above it. In all cases, plastic biliary stents 10F in diameter were used ranging from 5 to 10 cm in length. We describe in detail the technique of CBD stent placement using the choledochoscope as the advancing device. We also propose the use of intraoperative cholangiography instead of on-table endoscopy to check the final correct position of the stent. RESULTS: The median postoperative hospital stay was 2 days. Two patients developed transient hyperamylasemia in the immediate postoperative period. None of the patients developed short-term complications (<30 days), namely bile leak, CBD erosion, stent occlusion, or stent migration. The long-term results revealed early return to full daily activities and normal liver function tests. Stents were removed endoscopically 4 weeks after the initial procedure except in two patients who spontaneously passed them. CONCLUSION: We propose a 10F 10-cm biliary endoprosthesis placed under direct vision as a safe, effective, time-sparing, and cost-effective adjunct to CBD exploration through a choledochotomy. Placement of the endoprosthesis is associated with low morbidity and eliminates the complications related to T-tubes.

Cholelithiasis↗
PubMed1990

Immigration, stress, and depressive symptoms in a Mexican-American community.

This study assessed levels of depressive symptomatology in a household probability sample of Mexico-born (N = 706) and U.S.-born (N = 538) Mexican Americans. We hypothesized that immigration status differences in acculturation, strain, social resources, and social conflict, as well as differences in the associations of these variables with depression, would account for differences in depression between U.S.-born and Mexico-born respondents. U.S.-born Mexican Americans had higher depression scores than those born in Mexico. When cultural and social psychological variables were controlled in a multiple regression analysis, the immigrant status difference persisted. Tests of interaction terms suggested greater vulnerability to the effects of low acculturation and low educational attainment among the U.S.-born relative to those born in Mexico; however, the immigrant status difference persisted after controlling for these interactions. Unmeasured variables such as selective migration of persons with better coping skills, selective return of depressed immigrants, or generational differences in social comparison processes may account for the immigration status difference.

Acculturation↗
PubMed1984

Humoral and cellular immunity in patients with hepatic alveolar echinococcosis. A 2 year follow-up with and without flubendazole treatment.

Parameters of humoral and cellular immunity were assessed in 12 patients with alveolar echinococcosis (AE) of the liver before, during and after discontinuation of treatment with flubendazole (FZ). In infected patients, before any medical treatment values of serum IgG, IgA, total haemolytic complement and C4 were significantly higher than those observed in control subjects; IgA levels were higher in jaundiced patients. Specific antibodies assayed by indirect haemagglutination and immunoelectrophoresis were present only in infected patients and were shown to decrease by the sixth month of treatment; however, similar fluctuations were observed without treatment. The percentage and absolute number of B lymphocytes, and total circulating lymphocytes, were significantly lower in patients with AE. An impairment of functional activity of T cells assayed by the leucocyte migration test, with PPD and Candidin as antigens, was demonstrated despite a normal percentage of SRBC rosettes. The 'score' of migration index still decreased during FZ treatment and returned to initial values after the year of follow-up without treatment. These results suggest that human AE is associated with important immunological disturbances. Changes in humoral immunity can be unequivocally considered to be a consequence of the parasite infection. The primary or secondary nature of the impairment of cellular immune responses and its mechanisms remain to be elucidated. Flubendazole could be responsible for an increase of cellular immune alterations in these patients.

Adult↗
PubMed2001

A novel approach to ex vivo gene therapy for familial hypercholesterolemia using human amniotic epithelial cells as a transgene carrier.

This study has demonstrated the potential of human amniotic epithelial cells (HAEC) as a transgene carrier to treat patients with familial hypercholesterolemia (FH). One approach to liver-directed gene therapy is represented by transplantation of autologous hepatocytes that have been genetically modified in vitro. However, the hepatocytes must be isolated from surgically resected tissue and it is difficult to expand the hepatocytes in culture. In contrast, the advantages for using HAEC are the higher availability and the nonimmunogenicity after allotransplantation. Our strategy involved isolating HAEC from an amnion, transducing a human low-density lipoprotein receptor (LDLR) gene into these cells with a recombinant adenovirus, and transplanting the genetically modified cells into the liver of an animal model of FH. Each animal, treated with the LDLR-transduced HAEC, exhibited a substantial decrease in serum cholesterol with an eventual return to pretreatment level. Moreover, the transplanted HAEC migrated out of the sinusoids into the hepatic parenchyma and expressed the LDLRs until at least 20 days after transplantation. However, the transplanted HAEC markedly decreased in number after 10 days post-transplant with an increase of inflammatory cells. The temporary nature of the metabolic improvement may be associated with xenograft rejection and transient function of the adenoviral vector.

Adenoviruses, Human↗
PubMed2005

Neural stem cells implanted into MPTP-treated monkeys increase the size of endogenous tyrosine hydroxylase-positive cells found in the striatum: a return to control measures.

Neural stem cells (NSC) have been shown to migrate towards damaged areas, produce trophic factors, and replace lost cells in ways that might be therapeutic for Parkinson's disease (PD). However, there is very little information on the effects of NSC on endogenous cell populations. In the current study, effects of implanted human NSC (hNSC) on endogenous tyrosine hydroxylase-positive cells (TH+ cells) after treatment with 1-methyl-4-phenyl-1,2,3,6-tetra-hydropyridine (MPTP) were explored in nonhuman primates. After MPTP damage and in PD, the primate brain is characterized by decreased numbers of dopamine neurons in the substantia nigra (SN) and an increase in neurons expressing TH in the caudate nucleus. To determine how implanted NSC might affect these cell populations, 11 St. Kitts African green monkeys were treated with the selective dopaminergic neurotoxin, MPTP. Human NSC were implanted into the left and right caudate nucleus and the right SN of eight of the MPTP-treated monkeys. At either 4 or 7 months after NSC implants, the brains were removed and the size and number of TH+ cells in the target areas were assessed. The results were compared to data obtained from normal untreated control monkeys and to the three unimplanted MPTP-treated monkeys. The majority of hNSC were found bilaterally along the nigrostriatal pathway and in the substantia nigra, while relatively few were found in the caudate. In the presence of NSC, the number and size of caudate TH+ cells returned to non-MPTP-treated control levels. MPTP-induced and hNSC-induced changes in the putamen were less apparent. We conclude that after MPTP treatment in the primate, hNSC prevent the MPTP-induced upregulation of TH+ cells in the caudate and putamen, indicating that hNSC may be beneficial to maintaining a normal striatal environment.

Animals↗
PubMed1978

Effects of migration on the educational levels of the black resident population at the origin and destination, 1955--1960 and 1965--1970.

Using the 1960 and 1970 census data, this paper analyzes the net effects of the interregional migration of black males on the educational levels of the resident black male population at the regions of origin and destination. Significant variations are observed in the educational selectivity of out-migrants from each region, by region of destination. Comparing the educational levels of the return migrants to the South with those of the resident population in the nonsouthern regions provides no evidence that the return migrants are "failed" migrants. The net effect of interregional migration on the educational levels of the black male resident population at the regions of origin and destination is insignificant in most age groups, for both the 1955--1960 and 1965--1970 periods. In particular, in-migration from the South to nonsouthern regions has little effect on the educational levels of the resident population in most age groups. In fact, for nonsouthern regions, out-migration is more detrimental to the educational level of the resident black male population than is in-migration from the South. Furthermore, the net effect of interregional migration has declined from the 1955--1960 period to the 1965--1970 period.

Adult↗
PubMedDate not supplied

Cerebral infarction in rats using homologous blood emboli: development of a new experimental model.

A reproducible model of thromboembolism in the rat was developed and the temporal relationship between hydrogen clearance, regional cerebral blood flow (rCBF) and power spectral-analyzed electroencephalographic (EEG) activity explored for up to four hours postinsult. Sixteen rats were subjected to right internal carotid artery homologous blood embolization after electrocautery of the pterygopalatine artery. Four rats were subjected to sham operation. Cerebral angiography before and for up to four hours postinsult was used to verify the distal migration and fragmentation of the emboli. Preembolic mean rCBF was 62 +/- 9 ml . 100g-1 . min-1 and 65 +/- 12 ml . 100g-1 . min-1 in the embolized and contralateral sides, respectively. Based upon the distribution of the emboli at sacrifice, the experimental group of 12 rats fell into three subgroups: unilateral proximal embolism, n = 8; unilateral peripheral embolism, n = 3; and bilateral proximal embolism, n = 1. In unilateral proximal embolism the mean rCBF in the embolized hemisphere ranged between 10 and 20 ml . 100g-1 . min-1 and correlated well with changes in EEG power spectra. In unilateral peripheral embolism, the mean rCBF in the embolized hemisphere fell significantly 30 min postembolism. It returned progressively towards preembolic values as the embolic clots migrated distally and fragmented. Despite the restoration of rCBF, recovery of EEG activity appeared to be delayed. Our results did not show luxury perfusion after embolic insults. The time course for the reopening of the embolized artery and the delay in recovery of neuronal function (i.e., EEG activity) relative to the restoration of rCBF are discussed.

Animals↗
PubMed2003

Late bullet migration into the knee joint.

A 25-year-old active-duty police officer was found to have an intra-articular foreign body on radiographic study of his left knee joint. He had a gunshot wound to the midthigh 54 months prior to the presentation of symptoms. The bullet was lodged in the soft tissue without involving neurovascular structures. The patient complained of limited range of motion of the joint and a "rattle" sensation of the knee. Arthroscopically, a deformed metallic foreign body was found and retrieved. There was no injury inside the joint related to the loose body. These findings were consistent with a migrating bullet from the midthigh to the knee joint. The patient recovered uneventfully and returned to work.

Adult↗
PubMedDate not supplied

Intimal injury in vivo activates vascular smooth muscle cell migration and explant outgrowth in vitro.

In vivo induced endothelial injury results in an intimal thickening, mainly caused by stimulation of smooth muscle cells (SMC), which migrate into, and proliferate in, the denuded intima. We evaluated the manifestation and persistence of this stimulus in several in vitro explant and growth assays using aortic explants from either balloon catheter-injured rats or from sham-operated controls. SMC outgrowth from control explants started 48 hours after explantation, became half-maximal after 96 hours, with 74% of the explants showing outgrowth. Explants from balloon-injured aortas showed SMC outgrowth within 24 hours, became half-maximal after 48 hours, with 92% of the explants showing outgrowth. An interval of 4 to 7 days between balloon injury and sacrifice was optimal for obtaining accelerated outgrowth, while a 1-day interval showed a weak stimulation and a 21-day interval had no such effect. The in vivo stimulated cells grew more rapidly, resulting in a greater colony size per explant, and they became temporarily serum-independent. Increased growth rate persisted up to the second subculture but returned to normal in subsequent passages. Mechanisms of SMC migration can now be quantitatively assessed by replacing the intima with the tissue culture dish, allowing studies on the extent and persistence of atherogenic stimuli.

Animals↗
PubMed2005

Migration up and down the urban hierarchy and across the life course.

In this article, we begin by reviewing the concept of step migration that originated in E. G. Ravenstein's seminal papers "The Laws of Migration" (1885, 1889). As a result of the forces of the Industrial Revolution underway in 19th century Great Britain, migrants moved from farms to villages, from villages to towns, from towns to county seats, and thence to large cities. Throughout much of the industrialization era in the United States, net population movements similarly were upward within the urban hierarchy, and step migration today remains widespread throughout much of the still developing world. Our investigations of recent data and trends, however, suggest that the latest U.S. migration-pattern regime is a strongly contrasting one. Many of the major movements in the system of internal (or domestic) migration are flows down the urban hierarchy, although we note highly differentiated patterns for persons and households at specific stages of the life course. We make use of the newly defined metropolitan and micropolitan Core-Based Statistical Areas (CBSAs) and a seven-level size typology to tabulate origin-destination-specific migration flow data from both Census 2000 and IRS tax-return administrative records for the period 1995-2000. We discuss the causes for net movements being either upward or downward in the national urban hierarchy, including the effects of spatially focused immigration, and movement preferences at various ages, including migration in young adulthood associated with entering and leaving college and the military, as well as moves characteristic of the stages of family formation, childrearing, and retirement.

Adolescent↗