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PubMed1986

The effect of neutrophil migration on epithelial permeability.

To reach an inflammatory lesion, neutrophils must frequently traverse the epithelium of an infected organ. Whether the actual migration of neutrophils alters the epithelial permeability is unknown. Through the use of an in vitro model system it was possible to directly determine the effect of neutrophil emigration on the transepithelial electrical resistance of the monolayer. Human neutrophils (5 X 10(6) cells/ml) were placed in the upper compartment of a combined chemotaxis/resistance chamber and stimulated for 40 min by a gradient of 10(-7) M n-formyl-methionyl-leucyl-phenylalanine to traverse a confluent monolayer of canine kidney epithelial cells grown on micropore filters. Neither the chemoattractant alone (10(-5)-10(-9) M) nor the accumulation of an average of eight neutrophils per millimeter of epithelium lowered the transepithelial electrical resistance. However, under certain conditions the migration of neutrophils temporarily increased the permeability of the monolayer. The resistance fell approximately 48% within 5 min if the migratory cells were stimulated to reverse their migration across the same monolayer. As re-migration continued, the resistance returned to its initial levels within 60 min. Doubling the initial neutrophil concentration to 10 X 10(6) cells/ml resulted in the accumulation of an average of 66 neutrophils per millimeter of epithelium and an average fall in resistance of 46% (r = 0.98; P less than 0.001) in 40 min. If the resistance had fallen less than 45%, removal of the neutrophils remaining in the upper compartment resulted in a return of the transepithelial electrical resistance to its initial level within 65 min. However, when the fall was greater than 45%, the resistance only recovered to 23.5% of its initial levels within the same time frame. Thus, these results suggest that the integrity of an epithelium can, under certain conditions, be affected by the emigration of neutrophils, but that this effect is either completely or partially reversible within 65 min.

Animals↗
PubMed1992

Epidemic of malaria in Barmer district (Thar desert) of Rajasthan during 1990.

Barmer district of Rajasthan in Thar desert and hitherto a hypoendemic area for malaria came in the grip of a severe malaria epidemic during 1990. The epidemic occurred as an aftermath of floods, preceded by normal rains during 1988 and 1989 after a prolonged drought phase. The epidemic was spread over the whole district including Barmer town. Annual Parasite Incidence (API) and Annual falciparum Incidence (AFI) for the district touched record figures of 17.20 and 5.83 respectively while for the Barmer town they were 36.5 and 14.0 respectively. Out of the eight PHCs, Baitu PHC was the worst affected where the two indices touched all-time high figures of 55.3 and 19.6 per cent respectively. A total of 122 infants were reported positive for malaria, of which 103 were contributed by Baitu PHC alone. Eighty per cent infant positivity was spread over September and November, indicating a high rate of transmission. A total of 47 deaths due to cerebral malaria were reported. However, in view of the high infectivity among infants and paediatric groups there was a strong possibility of deaths among these groups which could not be verified. Entomological findings revealed that a sudden increase in An. culicifacies densities due to extensive breeding potential, as a sequel to floods, activated the transmission, which was maintained at a low level by An. stephensi, predominant in this desert region. Other factors which contributed to the intensity and extent of epidemic were the return of drought-migrated population from malarious areas, low cattle density, malaria non-immune population, inadequate and poor spray coverage and delayed radical treatment. Insecticide adult susceptibility tests revealed a high degree of resistance in An. stephensi against DDT and dieldrin.

Adolescent↗
PubMed2006

Quail poisoning in a child.

CONTEXT: It has been well known since ancient times that the consumption of quail may be deleterious to health. The European quail sub-species (Coturnix coturnix coturnix), common to Europe, North Africa, and western Asia is indeed potentially poisonous to humans, but only during the autumn migration (not during their return flight in spring). Quail poisoning is an acute dietary-toxicological syndrome. ISSUE: In this case report, we describe a rare, non-fatal case of quail poisoning in a 12-year-old boy. The victim was admitted to hospital 5 hours after the consumption of quail because of the signs and symptoms, as well as laboratory findings (elevation of serum muscle enzymes, myoglobinuria) significant of acute rhabdomyolysis. He was treated symptomatically with bed rest, forced continuous diuresis, urine alkalization, and maintenance of fluid and electrolyte balance. The victim recovered completely without sequelae after 8 days hospitalization. LESSONS: The aetiology of this syndrome is still unclear. It has been suggested that a toxic effect or a genetic sensitivity plays a major role. Many cases of quail poisoning in adults have been reported previously on the island of Lesbos during autumn. To our knowledge, this is the first case reported in a child.

Animals↗
PubMed1993

P-selectin and wound healing.

The history of the wound can by some accounts be traced nearly 5,000,000 years in the prehistoric ancestry of man (Majno, 1991). While there have been many descriptive accounts of the wound and wound healing over the centuries, in recent years rapid advances in the field of adhesion biology have added greatly to the understanding of the wound. Disruptions in the continuity of the vessel wall, whether by trauma or disease, induce a number of physiologic responses. The endothelium responds to fibrin contact in numerous ways including the rapid release of stored of von Willebrand factor and the expression of P-selectin upon the cell surface. Deposition of fibrin at the site of vascular injury serves other vital roles in the acute response to injury. Fibrin deposition stabilizes platelets as part of the development of a mural thrombus. Fibrin may also act to serve as a biological scaffold upon which inflammatory cells may adhere and participate in the acute response to injury. Finally, it is apparent that fibrin may act as a lattice upon which fibroblasts, smooth muscle cells and endothelial cells may adhere and migrate in order to return the vessel to its original state. In tumorigenesis, fibrinogen and fibrin may deposit in the perivascular space within the tumor and contribute by incompletely understood mechanisms to tumor growth and metastasis. The understanding of fibrin induced endothelial cell responses and how P-selectin and other endothelial cell adhesion molecules function in wound healing is important for understanding the vascular response to injury.

Animals↗
PubMed1995

[Eighty years of Japanese immigration in Brazil].

"Japanese emigration to Brazil started in 1908 with some eight hundred subsidized contract workers for coffee plantations. Hard conditions made many of them flee, and the paulista government suppressed subsidies for these projects; however, the Japanese emigration to Brazil kept on under Japanese subsidies from 1925 until 1934 when Brazil imposed immigration quotas unfavorable to Japanese immigration. International circumstances in the late 1930s and local prohibition on the use of the Japanese language in Brazil caused many immigrants to return to Japan between 1939-1941. Emigration to Brazil restarted as diplomatic relations between Japan and Brazil were reestablished in 1952 but decreased in the late 1960s. Subsequent economic evolution in both countries caused Japanese emigrants in Brazil and their [descendants] to initiate dekasegui [labor] migration from Brazil to Japan as from the late 1980s." (SUMMARY IN ENG)

Americas↗
PubMed1985

Forecasting interstate migration with limited data: a demographic-economic approach.

"The limitations of available migration data preclude a time-series approach of modeling interstate migration [in the United States]. The method presented here combines aspects of the demographic and economic approaches to forecasting migration in a manner compatible with existing data. Migration rates are modeled to change in response to changes in economic conditions. When applied to resently constructed data on migration based on income tax returns and then compared to standard demographic projections, the demographic-economic approach has a 20% lower total error in forecasting net migration by state for cohorts of labor-force age."

Americas↗
PubMed2006

Climate change and condition of herring (Clupea harengus) explain long-term trends in extent of skipped reproduction.

It is commonly assumed that iteroparous fish, once mature, normally reproduce in all consecutive seasons. Recent work has suggested, however, that in Norwegian spring-spawning herring-a population that undertakes extensive spawning migrations-almost one in two adults may skip their second spawning migration. Why should herring not return to spawn the year after first spawning, but instead wait an extra year? For herring, participation in distant, energetically costly, and risky spawning migrations will only pay off in terms of fitness if individuals are sufficiently large, and in sufficient condition, to both successfully migrate and spawn. Changes in the environment and individual condition should therefore affect the likelihood of skipped spawning. This paper describes long-term changes in the extent to which the second reproductive season is skipped in this herring population. These are shown to be linked to the size and condition of herring as first-time spawners, and to climatic factors possibly related to food availability. The findings corroborate the hypothesis that skipped reproduction results from trade-offs between current and future reproduction, growth and survival.

Animals↗
PubMed1988

The re-emergence of core region growth: a return to the metropolis?

Recent trends in migration in the United States are reviewed, focusing on the links between regional and metropolitan population change. Three explanations for the counterurbanization phenomenon of the 1970s are presented and their implications for future migration trends considered. The author concludes that "while 1970s core region declines may have been strongly linked to the counterurbanization process, post-1980 core region gains do not appear to signal a return to the metropolis."

Americas↗
PubMed1992

Changes in ligand binding to GABAA receptor sites in pacific salmon (Oncorhynchus) brain during spawning migration and "aging".

When several years old, pacific salmon return to the site of birth, to spawn. At this time, a rapid aging process begins and the fish die within a few weeks after reproducing. Age-related changes of high and low affinity GABA binding sites were studied in salmon brains at three different phases of the spawning migration, i.e. shortly after returning to the natal stream, at the time of spawning, and thereafter. High affinity GABA binding slightly increased while the fish deteriorated. The low affinity component showed a remarkable decrease in density and a concomitant increase in affinity during this final episode of salmon life.

Aging↗
PubMed1991

Targeted reintegration of expatriate brains into developing countries of origin: the EEC-IOM experience in Central America.

"The present article...reviews the major findings of the end-evaluation of the EEC-IOM project in Central America, the Dominican Republic and Panama, a five-year scheme funded by the Commission of the European Communities (EEC) and implemented by the International Organization for Migration (IOM), to promote a selective and development-oriented return of Latin American professionals to Costa Rica, the Dominican Republic, Honduras, Nicaragua and Panama.... The core objectives of this evaluation, undertaken in September-December 1989, were to assess the project's contribution to local socioeconomic, scientific and technological development through the selective supply of expatriate professionals to developing institutions operating in so-defined priority areas; to identify the returnees' personal reintegration patterns at the professional, socioeconomic and family-related levels; and to measure the project's cost effectiveness." (SUMMARY IN FRE AND SPA)

Americas↗
PubMed1997

To return or not to return? Politics vs. economics in China's brain drain.

"This study, based on 273 face-to-face interviews with students, scholars, and former residents of China in the United States in 1993, uses both qualitative and quantitative methods to explain people's views about returning to China. Although less than 9 percent of interviewees had concrete plans to return, over 32 percent were positively disposed to returning in the future. Key background variables that affect that decision are people's age, sex, social background in China, and their views about returning when they first left China. Concern about children's future was not significant, but having a wife abroad greatly increased the desire to stay abroad. Why people chose not to return varied significantly between people [who had] children and those who didn't."

Age Factors↗
PubMedDate not supplied

[Beyond the statistics: why are Quebec physicians emigrating?].

During the period 1986-1999, about 16% of the annual average number of active physicians in Quebec have left for the US or an other Canadian province. The absolute number was 2367. During the same period, 661 would have returned to Quebec. The majority of the outmigrating doctors were graduated from the anglophone university of the Province (although 44 percent are francophone) whereas the majority of the returning doctors were graduated from the 3 francophone universities of the Province. As a matter of fact, 78 percent of the returning doctors are francophone. The migration decision is equally linked to post-graduate training and occupational opportunities and job satisfaction. This feature should be related to an other: those who have returned to Quebec have had a geographic and occupational mobility level far lower than those who have not returned. Finally, it is noteworthy that there are significant differences between the doctors emigrating to the US and their colleagues going to an other Canadian province.

Adult↗
PubMed1982

The characterization of lymphocytes migrating through chronically inflamed tissues.

Afferent lymphatics draining Freund's adjuvant-induced granulomas and efferent lymphatics from normal subcutaneous lymph nodes were cannulated in sheep. It was previously reported that cells collected from these lymphatics, after being radiolabelled with 111In and returned to the animal intravenously, migrated from the blood back through the granuloma or lymph node into the lymph compartment from which they were originally obtained. Afferent lymph cells preferentially migrated out of the circulation in the granuloma rather than the lymph node. The cell responsible for this selective migration was found to be a small recirculating T lymphocyte. Macrophages and lymphoblasts did not demonstrate this migration. Similarly, B cells did not contribute to the lymphocyte migration observed. The migration of lymphocytes through normal uninflamed skin was examined. Afferent cells migrated through normal skin in the same way as through a granuloma, suggesting that neither antigen nor local inflammatory changes were responsible for this migration.

Animals↗
PubMed1992

Some observations on migration within and from the former USSR in the 1990s.

"Patterns of population distribution revealed from 1989 census data are used to assess how future population movements could be affected by current political, social, and economic changes. Much migration in the USSR has reflected central planning decisions as much as the spontaneous decisions of individuals. To the extent that the influence of the command economy diminishes and a market economy emerges, major new directions of migration flows can be expected. The return of ethnic 'expatriates' to home republics can be expected to increase, as can economic migration to areas with favorably perceived economic prospects, and migration to Central and Western Europe."

Demography↗