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At least 127 records · Page 7Linked to original sources
PubMed1972

Postoperative depression of tumour-directed cell-mediated immunity in patients with malignant disease.

Leucocytes from 46 melanoma patients, 45 breast carcinoma patients, and 95 control donors were tested by the leucocyte migration test against the supernatants of homogenates of malignant melanomas, breast carcinomas, simple breast tumours, and breasts showing simple cystic disease. By comparison with controls inhibition of migration occurred significantly more frequently when tumour patients' leucocytes were exposed to extracts of histogenetically similar tumours.Cell-mediated immunity to tumour-associated antigens was measured in 12 patients with breast carcinoma and 12 with malignant melanoma immediately before surgical operation and in the postoperative period. All patients tested before operation showed significant inhibition of migration on contact with extracts of histogenetically similar tumours. Postoperatively the degree of leucocyte migration inhibition was reduced in all patients with melanoma and breast carcinoma. Significant inhibition of leucocyte migration returned in most patients 6-22 days after operation.

Antigens, Neoplasm↗
PubMed1996

Effects of extracellular calcium on cholesteatoma migration and adhesion in vitro.

Cholesteatoma matrix and tympanic epithelia share the unique property of en mass migratory locomotion in vitro. Although this migratory behavior is not well understood, it is thought to be a major contributor to the pathogenesis and pathophysiology of cholesteatoma disease. We have surmised that en mass migration depends on tight calcium-dependent intercellular and substrate cellular adhesions. The purpose of this investigation was to determine the effects of a diminished extracellular calcium level on cholesteatoma migration and adhesion. Cholesteatoma matrixes obtained intraoperatively from patients undergoing mastoidectomies for chronic ear disease were cut into small fragments and grown in culture. When cultured specimens were exposed to low-calcium medium (0.14 mmol/L calcium), a greater than 10-fold reduction in the rate of migration was observed when compared with control values (1.8 mmol/L calcium). This reduction of migration returned to normal within 48 hours after extracellular calcium was replenished. Substrate cellular adhesion was also significantly reduced when cholesteatoma cells were grown in low-calcium medium. These observations were further supported by histomorphologic findings. Our findings suggest that calcium-dependent intercellular and substrate cellular adhesions are essential for cholesteatoma migration and adhesion. These studies further our understanding of the pathophysiology of cholesteatoma disease and may provide clues on how to better treat patients with this disease.

Calcium↗
PubMed1984

International migration and ethnic minorities: new fields for post-war sociology in the Federal Republic of Germany.

A review of studies concerning international migration and the development of ethnic minorities in the Federal Republic of Germany is presented. "This review will emphasize primarily the sociological literature in the Federal Republic of Germany in the context of developments since 1960. In addition to a discussion of the key issues and concepts employed, empirical research in the areas of social problems, housing and urban questions, education, the second generation, and return migration, among others, will be treated." (SUMMARY IN FRE)

Culture↗
PubMed2004

Paradox lost: explaining the Hispanic adult mortality advantage.

We tested three competing hypotheses regarding the adult "Hispanic mortality paradox": data artifact, migration, and cultural or social buffering effects. On the basis of a series of parametric hazard models estimated on nine years of mortality follow-up data, our results suggest that the "Hispanic" mortality advantage is a feature found only among foreign-born Mexicans and foreign-born Hispanics other than Cubans or Puerto Ricans. Our analysis suggests that the foreign-born Mexican advantage can be attributed to return migration, or the "salmon-bias" effect. However, we were unable to account for the mortality advantage observed among other foreign-born Hispanics.

Adult↗
PubMedDate not supplied

[The social and economic integration of Portuguese immigrants in Brazil at the end of the nineteenth century and in the twentieth century].

"This survey of Portuguese migration to Brazil analyses the Portuguese and Brazilian statistics to determine the volume, timing and quality of Portuguese immigrants to Brazil as well as the importance of Brazil in the overall Portuguese emigration. The patterns of geographic and economic mobility for the Brazilian resident Portuguese is examined, especially for the period since 1900." The analysis suggests that "though their rapid integration into the Brazilian economy may explain their very low rates of return migration--the lowest of the major European immigrants--they were also the most endogamous of the European migrants, having relatively low rates of intermarriage with native Brazilians and other immigrants." (SUMMARY IN ENG)

Acculturation↗
PubMed2006

Degeneration and regeneration of ultraviolet cone photoreceptors during development in rainbow trout.

Ultraviolet-sensitive (UVS) cones disappear from the retina of salmonid fishes during a metamorphosis that prepares them for deeper/marine waters. UVS cones subsequently reappear in the retina near sexual maturation and the return migration to natal streams. Cellular mechanisms of this UVS cone ontogeny were investigated using electroretinograms, in situ hybridization, and immunohistochemistry against opsins during and after thyroid hormone (TH) treatments of rainbow trout (Oncorhynchus mykiss). Increasing TH levels led to UVS cone degeneration. Labeling demonstrated that UVS cone degeneration occurs via programmed cell death and caspase inhibitors can inhibit this death. After the cessation of TH treatment, UVS cones regenerated in the retina. Bromodeoxyuridine (BrdU) was applied after the termination of TH treatment and was detected in the nuclei of cells expressing UVS opsin. BrdU was found in UVS cones but not other cone types. The most parsimonious explanation for the data is that UVS cones degenerated and UVS cones were regenerated from intrinsic retinal progenitor cells. Regenerating UVS cones were functionally integrated such that they were able to elicit electrical responses from second-order neurons. This is the first report of cones regenerating during natural development. Both the death and regeneration of cones in retinae represent novel mechanisms for tuning visual systems to new visual tasks or environments.

Animals↗
PubMed1987

Mortality among Hispanics in metropolitan Chicago: an examination based on vital statistics data.

This paper analyzes the mortality of Mexican Americans and Puerto Ricans residing in the Chicago metropolitan area. In a comparison of these two groups with nonHispanic whites in the same area, it was found that Hispanic mortality is unusually low for the two leading causes of death in the mainstream U.S. population. Explanations discussed include underdiagnosis, underreporting of illness, the "healthy migrant" thesis and possible return migration of elderly ill.

Adult↗
PubMed1976

Increased repair in DNA growing point regions after treatment of human lymphoma cells with N-methyl-N'-nitro-N-nitrosoguanidine.

Benzoylated naphthoylated DEAE-cellulose columns can be used to separate DNA growing point regions from the bulk of the DNA. We used the columns to estimate DNA excision repair in both fractions. Repair induced by acetoxy acetyl aminofluorene (AAAF), bromomethyl benz(alpha) anthracene (BMBA), and methyl methanesulfonate (MMS) occurs to an equal extent in growing point and non-replicating regions of the DNA. Excision repair induced by methyl nitrosourea (MNNU) and methyl nitronitrosoguanidine (MNNG) occurs to a greater extent in growing point regions of the DNA. The overall amount of methyl nitronitrosoguanidine-induced alkylation is the same for replicating and non-replicating regions of the DNA treated in vitro. We conclude that there is some special interaction between methyl-nitronitrosoguanidine and the growing point region in vivo. We suppose that strand displacement and branch migration return DNA lesions at the growing point to a double stranded configuration at which repair is possible.

Cell Division↗
PubMed1999

DNA damage produced by cadmium in a human fetal hepatic cell line.

Cadmium (Cd) is one of the most important heavy metal environmental toxicants. It alters a wide variety of cellular and biochemical processes. The objective of this work was to study DNA damage and recovery after acute and chronic CdCl2 treatment in a human fetal hepatic cell line (WRL-68 cells). Using the alkaline microgel electrophoresis assay that detects DNA single-strand breaks and/or alkali-labile sites in individual cells, we evaluated for levels of DNA damage. The mean migration length in control cells was 35.37+/-1. 43 microm (8% damaged cells), whereas the mean migration in cells treated with 0.005 microM CdCl2 for 3 h (acute low dose) was 65. 87+/-2.07 microm (88% damaged cells). Treatment with 0.01 microM CdCl2 for the same time (acute high dose) increased the mean migration length to 125.79+/-2.91 microm (92% damaged cells). However, a 0.005 microM CdCl2 treatment for 7 days (chronic treatment) only increased 65% DNA migration to 58.38+/-2.59 microm (88% damaged nucleus). Lipoperoxidative damage expressed as malondialdehyde (MDA) production per milligram of protein was 15. 7+/-2.6 for control cells, whereas in Cd-treated cells the values were 20.2+/-2.4 (acute low dose), 22.9+/-2.2 (acute high dose), and 22.6+/-2.1 (chronic treatment). To study the repair of DNA damage, cells were washed with 0.01 microM meso-2,3-dimercaptosuccinic acid (DMSA), and fresh Dulbecco's modified essential medium (DMEM) added. The percentage of damaged cells diminished after 90 min, with DNA migration returning to control values by 120 min. Cd treatment produced DNA single-strand breaks and the damage was greater in acute high dose treated cells. Lipid peroxidation values did not correlate with DNA single-strand breaks.

Cadmium↗
PubMed2005

Latino risk-adjusted mortality in the men screened for the Multiple Risk Factor Intervention Trial.

Latinos are now the largest minority in the United States, but their distinctive health needs and mortality patterns remain poorly understood. Proportional hazards regressions were used to compare Latino versus White risk- and income-adjusted mortality over 25 years' follow-up from 5,846 Latino and 300,647 White men screened for the Multiple Risk Factor Intervention Trial. Men were aged 35-57 years and residing in 14 states when screened in 1973-1975. Data on coronary heart disease risk factors, self-reported race/ethnicity, and home addresses were obtained at baseline; income was estimated by linking addresses to census data. Mortality follow-up through 1999 was obtained using the National Death Index. The fully adjusted Latino/White hazard ratio for all-cause mortality was 0.82 (95% confidence interval (CI): 0.77, 0.87), based on 1,085 Latino and 73,807 White deaths; this pattern prevailed over time and across states (thus, likely across Latino subgroups). Hazard ratios were significantly greater than one for stroke (hazard ratio = 1.30, 95% CI: 1.01, 1.68), liver cancer (hazard ratio = 2.02, 95% CI: 1.21, 3.37), and infection (hazard ratio = 1.69, 95% CI: 1.24, 2.32). A substudy found only minor racial/ethnic differences in the quality of Social Security numbers, birth dates, soundex-adjusted names, and National Death Index searches. Results were not likely an artifact of return migration or incomplete mortality data.

Adult↗
PubMed1998

Older parents' expectations of moving closer to their children.

Research shows that older parents engage in return migration in older to live closer to children from whom they receive care. However, less is known about how characteristics of adult children influence this process. Data for this analysis are from 5,382 older parents participating in the 1993/4 AHEAD national survey of adults aged 70 years old and older. Findings demonstrate that elderly parents who expect to move closer to adult children tend to be older, female, and have at least one child who is better-off financially than they are. Living alone magnifies the effect of poor self-rated health on expecting to move closer to a child. Random effects modeling of children's characteristics reveals that parents are more likely to expect to move closer to a daughter than to a son. Greater parental functional impairment was found to further depress the selection of sons. Overall, the findings suggest that older parents expect to move closer to adult children out of need and tend to select a target child with greater potential to provide support.

Adult↗
PubMed2006

Changes in juvenile coho salmon electro-olfactogram during and after short-term exposure to current-use pesticides.

For anadromous salmonids, olfaction is a critical sense, enabling return migration. In recent years, several pesticides have been identified that interfere with salmonid olfaction at concentrations in the microg/L range; thus, they may pose a risk to species longevity. In the present study, we investigated the acute effects of five agricultural pesticides on juvenile coho salmon (Oncorhynchus kisutch) olfaction using the electro-olfactogram (EOG), a measure of odorant-evoked field potentials. Electro-olfactogram responses to the odorant L-serine were measured during and following a 30-min exposure of the left olfactory rosette to chlorothalonil, endosulfan, glyphosate acid, iodocarb (IPBC), trifluralin, and 2,4-dichlorophenoxyacetic acid. With the relatively insoluble pesticides endosulfan and trifluralin, decreases in EOG amplitude were only apparent at relatively high concentrations (100 and 300 microg/L, respectively) following 20 min of exposure and were absent for chlorothalonil (1 mg/L). With the water-soluble herbicide glyphosate, significant EOG reductions occurred within 10 min of exposure to 1 mg/L and more rapidly with higher concentrations. Recovery of EOG post-glyphosate exposure was concentration-dependent, and complete recovery was not observed with some concentrations at 60 min postexposure. Dichlorophenoxyacetic acid only affected EOG at high concentration (100 mg/L), where it eliminated EOG within 2 min of exposure. With IPBC, EOG was decreased at 25 min of exposure to 1 microg/L; higher concentrations caused decreases to occur more rapidly. Excluding IPBC and glyphosate, all EOG reductions occurred at concentrations greater than the current Canadian water-quality guidelines and reported 96-h lethality values. Our results show that olfactory neurons can be impaired rapidly by some current-use pesticides, even at exposures in the low-microg/L range.

Animals↗
PubMed1998

Epidemic mycoplasmal conjunctivitis in house finches from eastern North America.

In the winter of 1993-94, house finches (Carpodacus mexicanus) with severe conjunctivitis (later shown to be caused by Mycoplasma gallisepticum) were first observed in sub-urban Washington D.C. (USA) and adjacent states. Using a large network of volunteer observers in eastern North America, we were able to track the monthly prevalence of the disease between November 1994 and March 1997. Using the information on 24,864 monthly data forms, we describe the very rapid spread of the conjunctivitis epidemic through the eastern house finch population. The epidemic first expanded mainly north, probably carried along by house finches on their return migration, then mainly toward the southeast, and later west. By March 1997, conjunctivitis had been reported from most of the eastern range of the house finch. The prevalence of the disease seemed to fluctuate seasonally with increases in the fall, probably as a result of dispersing juveniles. House finch numbers decreased throughout winter in areas with cold winters and high conjunctivitis prevalence, suggesting significant mortality associated with the disease.

Animals↗
PubMed1979

Adaptation of migrants or survival of the fittest? A Brazilian case.

The author attempts "to interpret the evolution of socioeconomic characteristics among internal migrants in Brazil with increasing duration of residence in destination areas." The relationship between the observed improvement in the socioeconomic conditions of migrants with increasing length of residence and return migration of the poorer, less successful migrants is examined

Americas↗
PubMed1983

Migrant employment and the recession--the case of the Irish in Britain.

"The past decade has witnessed a substantial contraction in the size of the Irishborn community in Britain. This paper uses shift share analysis to assess the extent to which job losses amongst the Irish in Britain over the years 1971-1977 may have induced return migration to Ireland. The article concludes that such 'push' factors are likely to have been relatively weak in comparison to the 'pull' of an Irish economy considerably more buoyant than that of Britain."

Behavior↗