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1.
Surg Endosc ; 38(2): 697-705, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38017160

RESUMO

BACKGROUND: The development of new perioperative treatment modalities to activate the immune system in colorectal cancer might have a beneficial effect on reducing the risk of recurrence after surgery. Calcium electroporation is a promising treatment modality that potentially modulates the tumor microenvironment. The aim of this study was to evaluate the safety of the procedure in the neoadjuvant setting in localized left-sided colorectal cancer (CRC). METHODS: The study included patients with potentially curable sigmoid or rectal cancer with no indication for other neoadjuvant treatment. Patients were offered calcium electroporation as a neoadjuvant treatment before elective surgery. Follow-up visits were conducted on the preoperative day before elective surgery, POD2, POD14, and POD30, with an evaluation of adverse events, impact on elective surgery, clinical examination, and quality of recovery. RESULTS: Endoscopic calcium electroporation was performed as an outpatient procedure in all 21 cases, with no procedure-related complications reported. At follow-up, five adverse events were registered, two of which were classified as serious adverse events. Surgery was performed as planned in 19 patients (median time to surgery, 8 days), and the final two patients underwent surgery with a delay due to adverse events (14 and 33 days). No significant impact on the quality of recovery scores nor inflammatory markers were seen before and after calcium electroporation, nor baseline and POD30. CONCLUSIONS: Endoscopic calcium electroporation is a safe and feasible procedure in patients with potentially curable CRC. The study showed limited side effects and limited impact on the following elective surgical resection.


Assuntos
Neoplasias Colorretais , Neoplasias Retais , Humanos , Neoplasias Colorretais/patologia , Terapia Neoadjuvante , Cálcio , Neoplasias Retais/cirurgia , Eletroporação , Microambiente Tumoral
2.
BJS Open ; 5(3)2021 05 07.
Artigo em Inglês | MEDLINE | ID: mdl-33963368

RESUMO

BACKGROUND: Personalized risk assessment provides opportunities for tailoring treatment, optimizing healthcare resources and improving outcome. The aim of this study was to develop a 90-day mortality-risk prediction model for identification of high- and low-risk patients undergoing surgery for colorectal cancer. METHODS: This was a nationwide cohort study using records from the Danish Colorectal Cancer Group database that included all patients undergoing surgery for colorectal cancer between 1 January 2004 and 31 December 2015. A least absolute shrinkage and selection operator logistic regression prediction model was developed using 121 pre- and intraoperative variables and internally validated in a hold-out test data set. The accuracy of the model was assessed in terms of discrimination and calibration. RESULTS: In total, 49 607 patients were registered in the database. After exclusion of 16 680 individuals, 32 927 patients were included in the analysis. Overall, 1754 (5.3 per cent) deaths were recorded. Targeting high-risk individuals, the model identified 5.5 per cent of all patients facing a risk of 90-day mortality exceeding 35 per cent, corresponding to a 6.7 times greater risk than the average population. Targeting low-risk individuals, the model identified 20.9 per cent of patients facing a risk less than 0.3 per cent, corresponding to a 17.7 times lower risk compared with the average population. The model exhibited discriminatory power with an area under the receiver operating characteristics curve of 85.3 per cent (95 per cent c.i. 83.6 to 87.0) and excellent calibration with a Brier score of 0.04 and 32 per cent average precision. CONCLUSION: Pre- and intraoperative data, as captured in national health registries, can be used to predict 90-day mortality accurately after colorectal cancer surgery.


Assuntos
Neoplasias Colorretais , Procedimentos Cirúrgicos do Sistema Digestório , Estudos de Coortes , Neoplasias Colorretais/cirurgia , Humanos , Modelos Logísticos , Medição de Risco
3.
BJS Open ; 2020 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-33022149

RESUMO

BACKGROUND: Mechanisms contributing to the perioperative stress response remain poorly understood. This study investigated changes in the amount of bacterial DNA in blood and the diversity of blood microbiota in the perioperative period in patients undergoing minimally invasive surgery for colonic cancer in an enhanced recovery after surgery setting. METHODS: DNA encoding the bacterial 16S ribosomal RNA gene (16S rDNA) in whole blood obtained the day before surgery, and on postoperative day (POD) 1 and POD 10-14 was amplified and quantified by PCR before sequencing for taxonomic assignment. Richness, evenness and similarity measures were calculated to compare microbiota between days. Differences in relative abundance were analysed using the linear discriminant analysis effect size (LEfSe) algorithm. RESULTS: Thirty patients were included between January and July 2016. The concentration of bacterial 16S rDNA in blood increased between the day before surgery and POD 1 (P = 0.025). Bacterial richness was lower on POD 10-14 than on the day before surgery and POD 1 (both P < 0·001). LEfSe analysis comparing the day before surgery and POD 10-14 identified changes in the abundance of several bacteria, including Fusobacterium nucleatum, which was relatively enriched on POD 10-14. CONCLUSION: These findings suggest that the blood of patients with colonic cancer harbours bacterial 16S rDNA, which increases in concentration after surgery.


ANTECEDENTES: Los mecanismos que contribuyen a la respuesta al estrés perioperatorio siguen siendo poco conocidos. Este estudio investigó los cambios en la cantidad de ADN bacteriano en la sangre y la diversidad de la microbiota sanguínea en el período perioperatorio en pacientes sometidos a cirugía mínimamente invasiva por cáncer de colon en el contexto de un programe de recuperación mejorada después de la cirugía. MÉTODOS: El ADN que codifica el gen de ARN ribosómico (rNDA) 16S bacteriano en sangre completa obtenido el día antes de la cirugía, el día 1 del postoperatorio y el día 10-14 del postoperatorio se amplificó y cuantificó mediante qPCR antes de la secuenciación para la asignación taxonómica. Se calcularon medidas de riqueza, uniformidad y similitud para comparar la microbiota entre los diferentes días. Las diferencias en la abundancia relativa se analizaron mediante un algoritmo de análisis discriminante lineal de tamaño de efecto (linear discriminant analysis effect size, LEfSe). RESULTADOS: De enero a julio de 2016 se incluyeron 30 pacientes. La concentración de 16S rNDA bacteriano en sangre aumentó desde el día antes de la operación al día 1 del postoperatorio. La riqueza bacteriana disminuyó en el día 10-14 del postoperatorio en comparación con el preoperatorio y el día 1 del postoperatorio. La comparación del preoperatorio y del día 10-14 postoperatorio por LEfSe identificó cambios en la abundancia de varias bacterias, incluida Fusobacterium nucleatum que mostró un enriquecimiento relativo el día 10-14 del postoperatorio. CONCLUSIÓN: Estos hallazgos sugieren que la sangre de los pacientes con cáncer de colon alberga 16S rNDA bacteriano cuya concentración aumenta tras la cirugía.

4.
Proc Natl Acad Sci U S A ; 95(25): 15107-11, 1998 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-9844023

RESUMO

The endogenous plant hormones salicylic acid (SA) and jasmonic acid (JA), whose levels increase on pathogen infection, activate separate sets of genes encoding antimicrobial proteins in Arabidopsis thaliana. The pathogen-inducible genes PR-1, PR-2, and PR-5 require SA signaling for activation, whereas the plant defensin gene PDF1.2, along with a PR-3 and PR-4 gene, are induced by pathogens via an SA-independent and JA-dependent pathway. An Arabidopsis mutant, coi1, that is affected in the JA-response pathway shows enhanced susceptibility to infection by the fungal pathogens Alternaria brassicicola and Botrytis cinerea but not to Peronospora parasitica, and vice versa for two Arabidopsis genotypes (npr1 and NahG) with a defect in their SA response. Resistance to P. parasitica was boosted by external application of the SA-mimicking compound 2, 6-dichloroisonicotinic acid [Delaney, T., et al. (1994) Science 266, 1247-1250] but not by methyl jasmonate (MeJA), whereas treatment with MeJA but not 2,6-dichloroisonicotinic acid elevated resistance to Alternaria brassicicola. The protective effect of MeJA against A. brassicicola was the result of an endogenous defense response activated in planta and not a direct effect of MeJA on the pathogen, as no protection to A. brassicicola was observed in the coi1 mutant treated with MeJA. These data point to the existence of at least two separate hormone-dependent defense pathways in Arabidopsis that contribute to resistance against distinct microbial pathogens.

5.
Plant Physiol ; 117(2): 609-18, 1998 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-9625714

RESUMO

The race-specific peptide elicitor AVR9 of the fungus Cladosporium fulvum induces a hypersensitive response only in tomato (Lycopersicon esculentum) plants carrying the complementary resistance gene Cf-9 (MoneyMaker-Cf9). A binding site for AVR9 is present on the plasma membranes of both resistant and susceptible tomato genotypes. We used mutant AVR9 peptides to determine the relationship between elicitor activity of these peptides and their affinity to the binding site in the membranes of tomato. Mutant AVR9 peptides were purified from tobacco (Nicotiana clevelandii) inoculated with recombinant potato virus X expressing the corresponding avirulence gene Avr9. In addition, several AVR9 peptides were synthesized chemically. Physicochemical techniques revealed that the peptides were correctly folded. Most mutant AVR9 peptides purified from potato virus X::Avr9-infected tobacco contain a single N-acetylglucosamine. These glycosylated AVR9 peptides showed a lower affinity to the binding site than the nonglycosylated AVR9 peptides, whereas their necrosis-inducing activity was hardly changed. For both the nonglycosylated and the glycosylated mutant AVR9 peptides, a positive correlation between their affinity to the membrane-localized binding site and their necrosis-inducing activity in MoneyMaker-Cf9 tomato was found. The perception of AVR9 in resistant and susceptible plants is discussed.


Assuntos
Cladosporium , Proteínas Fúngicas/metabolismo , Proteínas Fúngicas/toxicidade , Solanum lycopersicum/microbiologia , Sequência de Aminoácidos , Sítios de Ligação , Membrana Celular/metabolismo , Clonagem Molecular , Proteínas Fúngicas/síntese química , Genes de Plantas , Imunidade Inata/genética , Solanum lycopersicum/genética , Modelos Biológicos , Necrose , Doenças das Plantas , Folhas de Planta , Plantas Tóxicas , Mutação Puntual , Potexvirus/genética , Nicotiana/virologia , Virulência/genética
6.
Mol Plant Microbe Interact ; 10(7): 821-9, 1997 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-9304857

RESUMO

The AVR9 peptide of Cladosporium fulvum is an elicitor of the hypersensitive response in tomato plants carrying the Cf-9 resistance gene (MM-Cf9). To determine the structure-activity relationship of the AVR9 peptide, amino acids important for AVR9 elicitor activity were identified by independently substituting each amino acid of AVR9 by alanine. In addition, surface-exposed amino acid residues of AVR9 were substituted by other amino acids. Activity of the mutant Avr9 constructs was studied by expressing the constructs in MM-Cf9 tomato plants, using the potato virus X (PVX) expression system and assessing the severity of necrosis induced by each PVX::Avr9 construct. This allowed direct identification of amino acid residues of AVR9 that are essential for elicitor activity. We identified amino acid substitutions that resulted in AVR9 mutants with higher, similar, or lower elicitor activity compared to the wild-type AVR9 peptide. Some mutants had completely lost elicitor activity. A selection of peptides, representing different categories, was isolated and injected into leaves of MM-Cf9 plants. The necrosis-inducing activity of the isolated peptides correlated well with the necrosis induced by the corresponding PVX::Avr9 derivatives. Based on the necrosis-inducing activity of the mutant AVR9 peptides and the global structure of AVR9, we assigned sites in AVR9 that are important for its necrosis-inducing activity. We postulate that the "hydrophobic beta-loop" region of the AVR9 peptide is crucial for necrosis-inducing activity in tomato plants that carry the Cf-9 resistance gene.


Assuntos
Cladosporium/química , Proteínas Fúngicas/química , Clonagem Molecular , Proteínas Fúngicas/genética , Proteínas Fúngicas/farmacologia , Solanum lycopersicum/genética , Solanum lycopersicum/microbiologia , Mutagênese Sítio-Dirigida , Plantas Tóxicas , Conformação Proteica , Relação Estrutura-Atividade , Nicotiana/microbiologia
7.
Am J Vet Res ; 58(5): 461-6, 1997 May.
Artigo em Inglês | MEDLINE | ID: mdl-9140551

RESUMO

OBJECTIVE: To document gross and microscopic anatomic features of the collateral ligaments of the canine cubital joint and to determine their structural and material properties. ANIMALS: 37 canine cadavers. PROCEDURE: After measurement of ligament dimensions, the bone-collateral ligament-bone specimens were loaded in tension until failure, using a materials testing machine. Data from the load-displacement curves were used to determine the structural and material properties of the ligaments. Gross anatomic features were studied during dissection of the specimens from the medial collateral ligament (MCL) and lateral collateral ligament (LCL), which then were saved for microscopic examination. RESULTS: Failure load and stiffness values for the LCL were significantly (P < 0.05) greater than those for the MCL. The LCL had obvious cranial and caudal components that attached to the radius and ulna, respectively. The MCL also had cranial and caudal components; however, the cranial component was indistinct, appearing only as a slight thickening of the joint capsule. The caudal component was more prominent; as it extended distad, it had minor attachments to the interosseous and annular ligaments and attached principally on the caudolateral surface of the proximal portion of the radius. The caudal component did not have substantial attachment to the ulna in any of the specimens studied. Both ligaments were composed of closely packed, parallel fascicles of dense collagen, with scant amounts of fibrocartilage and no detectable elastin. CONCLUSIONS: Gross anatomic features of the collateral ligaments of the canine cubital joint indicate that they provide principal structural support to the joint; microscopic anatomic features are typical of other ligaments. The LCL is stronger and stiffer than the MCL; however, their material properties are similar. CLINICAL RELEVANCE: Knowledge of the sites of attachment of collateral ligament components is essential for surgeons undertaking repair or reconstruction of these structures.


Assuntos
Ligamentos Colaterais/anatomia & histologia , Cães/anatomia & histologia , Articulações/anatomia & histologia , Animais , Autopsia/métodos , Autopsia/veterinária , Fenômenos Biomecânicos , Peso Corporal/fisiologia , Ligamentos Colaterais/citologia , Cães/fisiologia , Feminino , Membro Anterior , Articulações/citologia , Masculino , Rádio (Anatomia)/anatomia & histologia , Ulna/anatomia & histologia
8.
Plant Cell ; 9(3): 367-79, 1997 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9090881

RESUMO

The avirulence gene Avr4 conditions avirulence of the biotrophic fungus Cladosporium fulvum on tomato genotypes carrying resistance gene Cf-4 (MM-Cf4). Strains of the fungus that circumvent Cf-4-specific resistance show various single point mutations in the coding region of the Avr4 gene. Similar to expression of the Avr4 gene, expression of the various virulent avr4 alleles is specifically induced during pathogenesis. Polyclonal antibodies raised against the AVR4 elicitor, however, did not detect AVR4 isoforms in MM-Cf4 plants infected by the different virulent strains, indicating that these isoforms are unstable. To analyze whether the AVR4 isoforms still possess specific elicitor activity, the avr4 alleles were expressed in MM-Cf4 plants by using the potato virus X (PVX)-based expression system. Inoculation with PVX::Avr4 resulted in the development of spreading lesions, eventually leading to plant death, whereas the various PVX::avr4 derivatives induced symptoms ranging from severe necrosis to no lesions at all. We conclude that instability of the AVR4 isoforms that are produced by virulent strains is a crucial factor in circumvention of Cf-4-mediated resistance.


Assuntos
Cladosporium/genética , Cladosporium/patogenicidade , Proteínas Fúngicas/biossíntese , Genes Fúngicos , Mutação Puntual , Solanum lycopersicum/genética , Solanum lycopersicum/microbiologia , Alelos , Sequência de Aminoácidos , Sequência de Bases , Proteínas Fúngicas/química , Proteínas Fúngicas/genética , Variação Genética , Genótipo , Imunidade Inata , Solanum lycopersicum/fisiologia , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , Transcrição Gênica , Virulência
9.
FEBS Lett ; 404(2-3): 153-8, 1997 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-9119054

RESUMO

The secondary structure and global fold of the AVR9 elicitor protein of Cladosporium fulvum has been determined by 2D NMR and distance-geometry protocols. The protein consists of three anti-parallel strands forming a rigid region of beta-sheet. On the basis of the NMR-derived parameters and distance geometry calculations, it is evident that the AVR9 protein is structurally very homologuous to carboxy peptidase inhibitor (CPI) of which the X-ray structure is known. The AVR9 protein reveals the presence of a cystine knot, which consists of a ring formed by two disulfide bridges and the interconnecting backbone through which the third disulfide bridge penetrates. This structural motif is found in several small proteins such as proteinase inhibitors, ion channel blockers and growth factors. The implications of the structural relationship between AVR9 and other biologically active proteins are discussed.


Assuntos
Cladosporium/metabolismo , Proteínas Fúngicas/química , Dobramento de Proteína , Estrutura Secundária de Proteína , Solanum lycopersicum/microbiologia , Sequência de Aminoácidos , Cistina , Proteínas Fúngicas/biossíntese , Proteínas Fúngicas/isolamento & purificação , Hidrogênio , Espectroscopia de Ressonância Magnética , Modelos Estruturais , Dados de Sequência Molecular , Fragmentos de Peptídeos/química , Proteínas Recombinantes de Fusão/biossíntese , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/isolamento & purificação
10.
Int J Popul Geogr ; 3(1): 31-47, 1997 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-12321148

RESUMO

"The purpose of this paper is to evaluate the impact of the post-unification East to West transfer of the German population on levels of spatial concentration and deconcentration in Eastern and Western Germany. Using 1991 internal migration data, it was found that German East-to-West migration served to deconcentrate regional population in the West, but concentrate population in the East. Regional variations in German East-to-West migration during 1991 can be explained by the availability of employment and housing, a distance-minimisation effect, and the location of relatives and friends."


Assuntos
Demografia , Emprego , Família , Geografia , Acessibilidade aos Serviços de Saúde , Habitação , Política , Densidade Demográfica , Dinâmica Populacional , Países Desenvolvidos , Economia , Emigração e Imigração , Europa (Continente) , Características da Família , Alemanha , População , Características de Residência
11.
Antonie Van Leeuwenhoek ; 71(1-2): 137-41, 1997 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9049025

RESUMO

The interaction between the biotrophic fungal pathogen Cladosporium fulvum and tomato complies with the gene-for-gene model. Resistance, expressed as a hypersensitive response (HR) followed by other defence responses, is based on recognition of products of avirulence genes from C. fulvum (race-specific elicitors) by receptors (putative products of resistance genes) in the host plant tomato. The AVR9 elicitor is a 28 amino acid (aa) peptide and the AVR4 elicitor a 106 aa peptide which both induce HR in tomato plants carrying the complementary resistance genes Cf9 and Cf4, respectively. The 3-D structure of the AVR9 peptide, as determined by 1H NMR, revealed that AVR9 belongs to a family of peptides with a cystine knot motif. This motif occurs in channel blockers, peptidase inhibitors and growth factors. The Cf9 resistance gene encodes a membrane-anchored extracellular glycoprotein which contains leucine-rich repeats (LRRs). 125I labeled AVR9 peptide shows the same affinity for plasma membranes of Cf9+ and Cf9- tomato leaves. Membranes of solanaceous plants tested so far all contain homologs of the Cf9 gene and show similar affinities for AVR9. It is assumed that for induction of HR, at least two plant proteins (presumably CF9 and one of his homologs) interact directly or indirectly with the AVR9 peptide which possibly initiates modulation and dimerisation of the receptor, and activation of various other proteins involved in downstream events eventually leading to HR. We have created several mutants of the Avr9 gene, expressed them in the potato virus X (PVX) expression system and tested their biological activity on Cf9 genotypes of tomato. A positive correlation was observed between the biological activity of the mutant AVR9 peptides and their affinity for tomato plasma membranes. Recent results on structure and biological activity of AVR4 peptides encoded by avirulent and virulent alleles of the Avr4 gene (based on expression studies in PVX) are also discussed as well as early defence responses induced by elicitors in tomato leaves and tomato cell suspensions.


Assuntos
Cladosporium/fisiologia , Proteínas Fúngicas/metabolismo , Glicoproteínas de Membrana/metabolismo , Doenças das Plantas/microbiologia , Proteínas de Plantas/metabolismo , Solanum lycopersicum/microbiologia , Membrana Celular/metabolismo , Cladosporium/genética , Proteínas Fúngicas/genética , Genes Fúngicos , Genes de Plantas , Solanum lycopersicum/genética , Solanum lycopersicum/metabolismo , Glicoproteínas de Membrana/genética , Proteínas de Plantas/genética
12.
Erde ; 123(3): 197-212, 1994.
Artigo em Alemão | MEDLINE | ID: mdl-12320693

RESUMO

"Until well after the Second World War, Canadian immigration policy favoured immigration in general, but it was characterised by ethnic and racial preferences and waves of discrimination. Only after 1962 was a less discriminatory point system...implemented which selected immigrants according to their standard of education and the demands of the Canadian labour market. This policy still indirectly favoured 'old' immigration groups. Since 1978 a new immigration law has been the basis of an annual immigration plan taking into account social, humanitarian, and economic criteria. One of its consequences has been the shift towards a greater proportion of Asian immigrants. This change has led to various tensions in the Canadian public." (SUMMARY IN ENG AND FRE)


Assuntos
Escolaridade , Emigração e Imigração , Emprego , Etnicidade , Mão de Obra em Saúde , Preconceito , Política Pública , Fatores Socioeconômicos , América , Canadá , Cultura , Demografia , Países Desenvolvidos , Economia , América do Norte , População , Características da População , Dinâmica Populacional , Classe Social , Problemas Sociais
14.
Planta ; 189(1): 60-9, 1993 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-7763357

RESUMO

Chickpea (Cicer arietinum L.) cell-suspension cultures were used to isolate one beta-1,3-glucanase (EC 3.2.1.29) and two chitinases (EC 3.2.1.14). The beta-1,3-glucanase (M(r) = 36 kDa) and one of the chitinases (M(r) = 32 kDa) belong to class I hydrolases with basic isoelectric points (10.5 and 8.5, respectively) and were located intracellularly. The basic chitinase (BC) was also found in the culture medium. The second chitinase (M(r) = 28 kDa), with an acidic isoelectric point of 5.7, showed homology to N-terminal sequences of class III chitinases and represented the main protein accumulating in the culture medium. Polyclonal antibodies raised against the basic beta-1,3-glucanase (BG) and the acidic chitinase (AC) were shown to be monospecific. The anti-AC antiserum failed to recognize the BC on immune blots, confirming the structural diversity between class I and class III chitinases. Neither chitinase exhibited lysozyme activity. All hydrolases were endo in action on appropriate substrates. The BC inhibited the hyphal growth of several test fungi, whereas the AC failed to show any inhibitory activity. Expression of BG activity appeared to be regulated by auxin in the cell culture and in the intact plant. In contrast, the expression of neither chitinase was apparently influenced by auxin, indicating a differential hormonal regulation of beta-1,3-glucanase and chitinase activities in chickpea. After elicitation of cell cultures or infection of chickpea plants with Ascochyta rabiei, both system were found to have hydrolase patterns which were qualitatively and quantitatively comparable.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Quitinases/metabolismo , Fabaceae/enzimologia , Glucana Endo-1,3-beta-D-Glucosidase/metabolismo , Isoenzimas/metabolismo , Plantas Medicinais , Sequência de Aminoácidos , Células Cultivadas , Quitinases/biossíntese , Quitinases/isolamento & purificação , Indução Enzimática , Fabaceae/microbiologia , Glucana Endo-1,3-beta-D-Glucosidase/biossíntese , Glucana Endo-1,3-beta-D-Glucosidase/isolamento & purificação , Isoenzimas/isolamento & purificação , Fungos Mitospóricos/fisiologia , Dados de Sequência Molecular
17.
Geogr Perspect ; (61): 30-42, 1988.
Artigo em Inglês | MEDLINE | ID: mdl-12343074

RESUMO

"Age-specific migration changes between 1977 and 1980 reveal several modifications in the pattern of population redistribution in the Federal Republic and suggest a major alteration of the West German internal migration system. In 1980, both the 30 to 49...and the 50+ year olds move (in the net) out of densely populated regions and into sparsely populated areas. A net out-migration occurs from the large, densely populated urban regions with strong and contemporary economic bases as well as from areas with structural economic problems. Densely populated regions lose more migrants while sparsely populated areas retain additional potential movers. Diverse explanations are suggested for these age-selective migration changes."


Assuntos
Fatores Etários , Demografia , Economia , Emigração e Imigração , Dinâmica Populacional , Países Desenvolvidos , Europa (Continente) , Geografia , Alemanha Ocidental , População , Características da População
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