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1.
Sci Rep ; 12(1): 2488, 2022 02 15.
Artículo en Inglés | MEDLINE | ID: mdl-35169194

RESUMEN

In vitro fertilization is typically associated with high failure rates per transfer, leading to an acute need for the identification of embryos with high developmental potential. Current methods are tailored to specific times after fertilization, often require expert inspection, and have low predictive power. Automatic methods are challenged by ambiguous labels, clinical heterogeneity, and the inability to utilize multiple developmental points. In this work, we propose a novel method that trains a classifier conditioned on the time since fertilization. This classifier is then integrated over time and its output is used to assign soft labels to pairs of samples. The classifier obtained by training on these soft labels presents a significant improvement in accuracy, even as early as 30 h post-fertilization. By integrating the classification scores, the predictive power is further improved. Our results are superior to previously reported methods, including the commercial KIDScore-D3 system, and a group of eight senior professionals, in classifying multiple groups of favorable embryos into groups defined as less favorable based on implantation outcomes, expert decisions based on developmental trajectories, and/or genetic tests.


Asunto(s)
Implantación del Embrión , Transferencia de Embrión/métodos , Desarrollo Embrionario , Fertilización In Vitro/métodos , Femenino , Humanos
2.
Theor Appl Genet ; 121(3): 511-33, 2010 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-20401460

RESUMEN

A genetic map of melon enriched for fruit traits was constructed, using a recombinant inbred (RI) population developed from a cross between representatives of the two subspecies of Cucumis melo L.: PI 414723 (subspecies agrestis) and 'Dulce' (subspecies melo). Phenotyping of 99 RI lines was conducted over three seasons in two locations in Israel and the US. The map includes 668 DNA markers (386 SSRs, 76 SNPs, six INDELs and 200 AFLPs), of which 160 were newly developed from fruit ESTs. These ESTs include candidate genes encoding for enzymes of sugar and carotenoid metabolic pathways that were cloned from melon cDNA or identified through mining of the International Cucurbit Genomics Initiative database (http://www.icugi.org/). The map covers 1,222 cM with an average of 2.672 cM between markers. In addition, a skeleton physical map was initiated and 29 melon BACs harboring fruit ESTs were localized to the 12 linkage groups of the map. Altogether, 44 fruit QTLs were identified: 25 confirming QTLs described using other populations and 19 newly described QTLs. The map includes QTLs for fruit sugar content, particularly sucrose, the major sugar affecting sweetness in melon fruit. Six QTLs interacting in an additive manner account for nearly all the difference in sugar content between the two genotypes. Three QTLs for fruit flesh color and carotenoid content were identified. Interestingly, no clear colocalization of QTLs for either sugar or carotenoid content was observed with over 40 genes encoding for enzymes involved in their metabolism. The RI population described here provides a useful resource for further genomics and metabolomics studies in melon, as well as useful markers for breeding for fruit quality.


Asunto(s)
Carbohidratos/genética , Cucurbitaceae/genética , Etiquetas de Secuencia Expresada , Frutas/genética , Genes de Plantas , Marcadores Genéticos/genética , Sitios de Carácter Cuantitativo/genética , beta Caroteno/metabolismo , Análisis del Polimorfismo de Longitud de Fragmentos Amplificados , Mapeo Cromosómico , Cromosomas de las Plantas/genética , Cucurbitaceae/crecimiento & desarrollo , Cartilla de ADN/química , Cartilla de ADN/genética , Frutas/química , Frutas/crecimiento & desarrollo , Genoma de Planta , Fenotipo , beta Caroteno/genética
3.
Neuron ; 20(2): 341-51, 1998 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-9491994

RESUMEN

Native T-type voltage-dependent calcium channels are low voltage-activated and have a small single channel conductance of 5-8 pS, which distinguishes them from any known cloned calcium channels whose conductances are 12-25 pS. Here, we show that when alpha1B, alpha1E, or alpha1C are expressed in COS7 cells, which contain no endogenous calcium channel subunits or calcium channels, they each exhibit a 4-7 pS channel as well as a large conductance channel. At low depolarizations, or when the alpha1 subunit is expressed in the absence of auxiliary alpha2-delta or beta subunits, the small conductance channels are seen alone, and their biophysical properties, including voltage dependence and kinetics of activation and inactivation, are very similar to native T-type calcium channels.


Asunto(s)
Canales de Calcio/química , Canales de Calcio/genética , Activación del Canal Iónico/fisiología , Animales , Células COS , Conductividad Eléctrica , Expresión Génica , Glioma , Células Híbridas/química , Células Híbridas/fisiología , Activación del Canal Iónico/efectos de los fármacos , Neuroblastoma , Técnicas de Placa-Clamp , Ratas , Transfección
4.
Proc Inst Mech Eng H ; 222(2): 209-19, 2008 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-18441756

RESUMEN

The aetiology, in terms of both initiation and progression, of the deformity in idiopathic scoliosis is at present unclear. Even in neuromuscular cases, the mechanisms underlying progression are not fully elucidated. It is thought, however, that asymmetrical loading is involved in the progression of the disease, with evidence mainly from animal studies and modelling. There is, however, very little direct information as to the origin or mechanism of action of these forces in the scoliotic spine. This review describes the concept of intervertebral disc pressure or stress and examines possible measurement techniques. The biological and mechanical consequences of abnormalities in these parameters are described. Future possible studies and their clinical significance are also briefly discussed. Techniques of pressure measurement have culminated in the development of 'pressure profilometry', which provides stress profiles across the disc in mutually perpendicular axes. A hydrated intervertebral disc exhibits mainly hydrostatic behaviour. However, in pathological states such as degeneration and scoliosis, non-hydrostatic behaviour predominates and annular peaks of stress occur. Recent studies have shown that, in scoliosis, high hydrostatic pressures are seen with asymmetrical stresses from concave to convex sides. These abnormalities could influence both disc and endplate cellular activity directly, causing asymmetrical growth and matrix changes. In addition, disc cells could be influenced via nutritional changes consequent to end-plate calcification. Evidence suggests that the stress environment of the scoliotic disc is abnormal, probably generated by high and asymmetrical loading of non-muscular origin. If present in the scoliotic spine during daily activities, this could generate a positive feedback of cellular changes, resulting in curve progression. Future advances in understanding may rely on the development of computer models owing to the difficulties of in-vivo invasive measurements.


Asunto(s)
Desplazamiento del Disco Intervertebral/fisiopatología , Disco Intervertebral/fisiopatología , Modelos Biológicos , Escoliosis/fisiopatología , Simulación por Computador , Humanos , Presión , Estrés Mecánico , Soporte de Peso
5.
J Ovarian Res ; 11(1): 95, 2018 Nov 21.
Artículo en Inglés | MEDLINE | ID: mdl-30463623

RESUMEN

BACKGROUND: It has been shown - mostly in animal models - that circadian clock genes are expressed in granulosa cells and in corpora luteum and might be essential for the ovulatory process and steroidogenesis. OBJECTIVE: We sought to investigate which circadian clock genes exist in human granulosa cells and whether their expression and activity decrease during aging of the ovary. STUDY DESIGN: Human luteinized granulosa cells were isolated from young (age 18-33) and older (age 39-45) patients who underwent in-vitro fertilization treatment. Levels of clock genes expression were measured in these cells 36 h after human chorionic gonadotropin stimulation. METHODS: Human luteinized granulosa cells were isolated from follicular fluid during oocyte retrieval. The mRNA expression levels of the circadian genes CRY1, CRY2, PER1, PER2, CLOCK, ARNTL, ARNTL2, and NPAS2 were analyzed by quantitative polymerase chain reaction. RESULTS: We found that the circadian genes CRY1, CRY2, PER1, PER2, CLOCK, ARNTL, ARNTL2, and NPAS2, are expressed in cultured human luteinized granulosa cells. Among these genes, there was a general trend of decreased expression in cells from older women but it reached statistical significance only for PER1 and CLOCK genes (fold change of 0.27 ± 0.14; p = 0.03 and 0.29 ± 0.16; p = 0.05, respectively). CONCLUSIONS: This preliminary report indicates that molecular circadian clock genes exist in human luteinized granulosa cells. There is a decreased expression of some of these genes in older women. This decline may partially explain the decreased fertility and steroidogenesis of reproductive aging.


Asunto(s)
Envejecimiento/genética , Péptidos y Proteínas de Señalización del Ritmo Circadiano/genética , Células de la Granulosa/metabolismo , Adolescente , Adulto , Femenino , Expresión Génica , Humanos , Luteinización , Persona de Mediana Edad , ARN Mensajero/metabolismo , Adulto Joven
6.
Water Sci Technol ; 54(3): 83-8, 2006.
Artículo en Inglés | MEDLINE | ID: mdl-17037137

RESUMEN

Wastewater reuse in arid regions is important for the production of a water resource to be utilised for non-potable purposes and to prevent the environmental transmission of disease-causing agents. This study was conducted to evaluate the effect of water quality on the comparative disinfection efficiency of viruses, bacteria and spores by UV irradiation. Furthermore, the microbial quality of effluent produced by coagulation, high rate filtration (HRF) and either UV irradiation or chlorination was determined. Using low pressure collimated beam, a UV dose of 80 mWs/cm2 was needed to achieve a 3-log10 inactivation of either rotavirus SA-11 or coliphage MS2, whereas over 5-log10 inactivation of E. coli was reached with a dose of only 20 mWs/cm2. B. subtilis inactivation was found to be linear up to a dose of 40 mWs/cm2 and then a tailing up to a UV dose of 120 mWs/cm2 was observed. It is worth noting that effluent turbidity of < 5 NTU did not influence the inactivation efficiency of UV irradiation. Operation of a pilot plant to treat secondary effluent by coagulation, HRF and UV disinfection at a UV dose of 80 mWs/cm2 resulted in the production of high quality effluent in compliance with the Israel standards for unrestricted irrigation (< 10 CFU/100 mL faecal coliform and turbidity of < 5 NTU). Sulphite reducing clostridia (SRC) were found to be more resistant than coliphages and F coliform for UV irradiation. The results of this study indicated that UV disinfection is suitable for the production of effluents for unrestricted irrigation of food crops.


Asunto(s)
Bacterias/efectos de la radiación , Rayos Ultravioleta , Virus/efectos de la radiación , Microbiología del Agua , Cloro/farmacología , Desinfección/métodos , Proyectos Piloto
7.
J Neurosci ; 21(21): 8495-504, 2001 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-11606638

RESUMEN

Voltage-gated calcium channel alpha1 subunits consist of four domains (I-IV), each with six transmembrane segments. A number of truncated isoforms have been identified to occur as a result of alternative splicing or mutation. We have examined the functional consequences for expression of full-length Ca(v)2.2 (alpha1B) of its coexpression with truncated constructs of Ca(v)2.2. Domains I-II or domains III-IV, when expressed individually, together with the accessory subunits beta1b and alpha2delta-1, did not form functional channels. When they were coexpressed, low-density whole-cell currents and functional channels with properties similar to wild-type channels were observed. However, when domain I-II, domain III-IV, or domain I alone were coexpressed with full-length Ca(v)2.2, they markedly suppressed its functional expression, although at the single channel level, when channels were recorded, there were no differences in their biophysical properties. Furthermore, when it was coexpressed with either domain I-II or domain I, the fluorescence of green fluorescent protein (GFP)-Ca(v)2.2 and expression of Ca(v)2.2 protein was almost abolished. Suppression does not involve sequestration of the Ca(v)beta subunit, because loss of GFP-Ca(v)2.2 expression also occurred in the absence of beta subunit, and the effect of domain I-II or domain I could not be mimicked by the cytoplasmic I-II loop of Ca(v)2.2. It requires transmembrane segments, because the isolated Ca(v)2.2 N terminus did not have any effect. Our results indicate that the mechanism of suppression of Ca(v)2.2 by truncated constructs containing domain I involves inhibition of channel synthesis, which may represent a role of endogenously expressed truncated Ca(v) isoforms.


Asunto(s)
Canales de Calcio Tipo N/metabolismo , Expresión Génica/efectos de los fármacos , Subunidades de Proteína , Proteínas Recombinantes de Fusión/farmacología , Animales , Células COS , Canales de Calcio Tipo N/genética , Genes Dominantes , Proteínas Fluorescentes Verdes , Proteínas Luminiscentes/genética , Mutagénesis Sitio-Dirigida , Técnicas de Placa-Clamp , Estructura Terciaria de Proteína/fisiología , Conejos , Proteínas Recombinantes de Fusión/genética , Transfección
8.
J Neurosci ; 21(16): 6095-104, 2001 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-11487633

RESUMEN

The mouse mutant ducky, a model for absence epilepsy, is characterized by spike-wave seizures and ataxia. The ducky gene was mapped previously to distal mouse chromosome 9. High-resolution genetic and physical mapping has resulted in the identification of the Cacna2d2 gene encoding the alpha2delta2 voltage-dependent calcium channel subunit. Mutations in Cacna2d2 were found to underlie the ducky phenotype in the original ducky (du) strain and in a newly identified strain (du(2J)). Both mutations are predicted to result in loss of the full-length alpha2delta2 protein. Functional analysis shows that the alpha2delta2 subunit increases the maximum conductance of the alpha1A/beta4 channel combination when coexpressed in vitro in Xenopus oocytes. The Ca(2+) channel current in acutely dissociated du/du cerebellar Purkinje cells was reduced, with no change in single-channel conductance. In contrast, no effect on Ca(2+) channel current was seen in cerebellar granule cells, results consistent with the high level of expression of the Cacna2d2 gene in Purkinje, but not granule, neurons. Our observations document the first mammalian alpha2delta mutation and complete the association of each of the major classes of voltage-dependent Ca(2+) channel subunits with a phenotype of ataxia and epilepsy in the mouse.


Asunto(s)
Ataxia/genética , Canales de Calcio/genética , Canales de Calcio/metabolismo , Epilepsia/genética , Células de Purkinje/metabolismo , Animales , Ataxia/complicaciones , Encéfalo/metabolismo , Encéfalo/patología , Células Cultivadas , Cerebelo/citología , Cerebelo/metabolismo , Mapeo Cromosómico , Electroencefalografía , Epilepsia/complicaciones , Homocigoto , Hibridación in Situ , Ratones , Ratones Mutantes Neurológicos , Datos de Secuencia Molecular , Mutación , Oocitos/metabolismo , Técnicas de Placa-Clamp , Fenotipo , Subunidades de Proteína , Células de Purkinje/patología , ARN Mensajero/análisis , ARN Mensajero/biosíntesis , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Xenopus
9.
Hum Pathol ; 31(11): 1404-10, 2000 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11112216

RESUMEN

Microvillous inclusion disease (MID) is characterized by diffuse villous atrophy without inflammatory changes. While increased apoptosis has been related to mucosal flattening in celiac disease, the role of apoptosis in the pathogenesis of MID is unknown. The aim of this study was to assess the rates of apoptosis and cell proliferation in MID and to compare them with those of normal controls and celiac disease. Small intestinal biopsies from 5 infants with MID, 10 children with normal villous architecture, and 10 children with untreated celiac disease were stained with the terminal uridine deoxynucleotidyl nick end labeling (TUNEL) method to assess apoptotic activity, and with Ki-67 immunohistochemistry to assess cellular proliferation. TUNEL and Ki-67 positive enterocytes were counted in a minimum of 20 well oriented half crypts per section. The percentage of apoptotic cells per crypt (apoptotic index) in normal, MID, and celiac biopsies was 0.03 +/- 0.01%, 0.08 +/- 0.08%, and 0.16 +/- 0.3%, respectively. Significant differences were found between normal and MID, and between normal and celiac cases. The percentage of Ki-67 positive cells per crypt (proliferation index) in normal, MID, and celiac cases was 14 +/- 2.5%, 28 +/- 9.2%, and 56 +/- 14%. Significant differences were found between the 3 groups. In conclusion, (1) enterocyte apoptosis and proliferation are increased in MID; (2) apoptosis appears to be an important factor of cell loss and may be, at least in part, responsible for villous atrophy in MID; and (3) crypts in MID are hyperplastic and not hypoplastic. HUM PATHOL 31:1404-1410.


Asunto(s)
Apoptosis , Diarrea Infantil/patología , Enterocitos/patología , Intestino Delgado/patología , Microvellosidades/patología , Atrofia , ADN/análisis , Diarrea Infantil/genética , Diarrea Infantil/metabolismo , Enterocitos/metabolismo , Femenino , Humanos , Etiquetado Corte-Fin in Situ , Lactante , Recién Nacido , Intestino Delgado/metabolismo , Antígeno Ki-67/metabolismo , Masculino , Microvellosidades/metabolismo , Índice Mitótico
10.
Neuroreport ; 8(11): 2539-45, 1997 Jul 28.
Artículo en Inglés | MEDLINE | ID: mdl-9261823

RESUMEN

The bursting K+ channel is the most common channel in fused Torpedo presynaptic nerve terminals. It possesses the property of 'statistical memory', demonstrated by non-random probability of channel opening. We examined the voltage dependence of the statistical memory and report that removal of channel inactivation by hyperpolarization abolishes it. Addition of the potassium channel blocker 4-aminopyridine to the bath solution led to disappearance of statistical memory, while raising extracellular potassium concentration had the opposite effect. Another common channel at Torpedo nerve terminals which is a non-selective channel did not exhibit statistical memory. We conclude that statistical memory is a channel-specific phenomenon and speculate regarding its possible role in cellular and network properties of the nervous system.


Asunto(s)
Órgano Eléctrico/fisiología , Terminaciones Nerviosas/fisiología , Canales de Potasio/fisiología , Sinaptosomas/fisiología , 4-Aminopiridina/farmacología , Animales , Estimulación Eléctrica , Potenciales Evocados , Activación del Canal Iónico , Fusión de Membrana , Potenciales de la Membrana/efectos de los fármacos , Probabilidad , Sinaptosomas/efectos de los fármacos , Torpedo
11.
Anticancer Res ; 18(6A): 4237-41, 1998.
Artículo en Inglés | MEDLINE | ID: mdl-9891473

RESUMEN

BACKGROUND: The tumor-suppressive effects of the rat soluble p53 antigen on chemically induced skin cancer in mice and the role of the spleen in the immune response to a carcinogen and vaccination were studied. METHODS: Skin cancer was induced by 9,10-dimethyl-1,2-benzanthracene (DMBA). Vaccination was initiated by injection of liposomes with the soluble p53 antigen (10-12 micrograms/mouse) while boosters were with the p53 mixed with Freund's incomplete adjuvant (two injections). Four months later, the spleen and tumors were removed and examined morphometrically (determination of areas of different spleen's zones) and immunohistochemically (determination of number of B lymphocytes and macrophages, apoptotic index). The following groups of mice were studied: A) control non treated mice; Bl) tumor-free mice treated with a carcinogen; B2) tumor-bearing mice; Cl) tumor-free vaccinated mice exposed to a carcinogen; C2) tumor-bearing vaccinated mice. RESULTS: Mice exposed to a carcinogen, which were tumor-free, displayed high proliferative activity of the spleenic lymphoid constitutes such as B lymphocytes and macrophages. This was reflected in the remarkable transformation of B lymphocytes in lymphoblasts (blast transformation) and an increase in the area of germinal centers, compared to untreated controls. In tumor-bearing non vaccinated mice, significantly more spleenic apoptotic cells were found than in their tumor-free counterparts. Shrinkage of the mantle layer and a decrease in cellular density of follicles were seen in all carcinogen-treated mice, reflecting the reduced total production of lymphoid cells, and thus the insufficiency of the immune reaction of animals to a carcinogen. A sharp decrease in the apoptotic index in the spleen of tumor-free mice may reflect an inhibition of apoptotic activity of the spleen by a carcinogen. Vaccination with the soluble p53 protein decreased the incidence of tumors and their size, significantly increased the apoptotic index within tumors, and reversed the splenic parameters of immune insufficiency. CONCLUSIONS: The immune system is active during tumorigenesis. Vaccination with the soluble p53 antigen had positive tumor-suppressive effects. The findings may facilitate the development of vaccines for the prevention of recurrent cancers in humans.


Asunto(s)
Anticarcinógenos/uso terapéutico , Vacunas contra el Cáncer , Carcinoma de Células Escamosas/inmunología , Neoplasias Cutáneas/inmunología , Neoplasias Cutáneas/prevención & control , Bazo/inmunología , Proteína p53 Supresora de Tumor/uso terapéutico , 9,10-Dimetil-1,2-benzantraceno , Animales , Anticarcinógenos/administración & dosificación , Apoptosis , Linfocitos B/patología , Carcinoma de Células Escamosas/inducido químicamente , Carcinoma de Células Escamosas/patología , Carcinoma de Células Escamosas/prevención & control , Portadores de Fármacos , Humanos , Inmunización Secundaria , Incidencia , Liposomas , Activación de Linfocitos , Macrófagos/patología , Ratones , Ratones Endogámicos BALB C , Ratas , Neoplasias Cutáneas/inducido químicamente , Neoplasias Cutáneas/patología , Bazo/patología , Proteína p53 Supresora de Tumor/administración & dosificación
12.
Am J Surg ; 181(5): 471-4, 2001 May.
Artículo en Inglés | MEDLINE | ID: mdl-11448446

RESUMEN

BACKGROUND: Because the surgical treatment of achalasia is directed at the palliation of chronic symptoms, it is important to assess how surgery affects patients' health-related quality of life (HRQL). METHODS: We evaluated upper gastrointestinal symptoms, satisfaction, and HRQL in 19 patients with achalasia before and after undergoing a laparoscopic Heller myotomy and partial fundoplication. HRQL was assessed using the Medical Outcomes Study 36-item short form health survey (SF-36). RESULTS: The mean age of the patients was 40 years (range 16 to 74), and 58% were men. After a median follow-up of 21 months (range 2 to 35), 12 of 16 patients were satisfied with the results of their surgery. Liquid and solid dysphagia scores were improved after surgery, and the prevalence of heartburn symptoms did not change. Although all the health concepts measured by the SF-36 instrument showed some improvement, statistically significant increases (on a 0 to 100 scale) were detected in physical functioning (11.1, P = 0.02), role-physical (25.0, P = 0.05), bodily pain (12.2, P = 0.01), vitality (13.7, P = 0.02), and social functioning (18.4, P = 0.02). CONCLUSIONS: Most aspects of HRQL improve after a laparoscopic Heller myotomy and partial fundoplication for achalasia.


Asunto(s)
Acalasia del Esófago/cirugía , Fundoplicación/métodos , Laparoscopía , Calidad de Vida , Actividades Cotidianas , Adolescente , Adulto , Anciano , Trastornos de Deglución , Acalasia del Esófago/patología , Femenino , Pirosis , Humanos , Masculino , Persona de Mediana Edad , Evaluación de Resultado en la Atención de Salud , Cuidados Paliativos , Índice de Severidad de la Enfermedad , Conducta Social , Resultado del Tratamiento
13.
Gerontologist ; 33(3): 308-14, 1993 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-8325517

RESUMEN

We interviewed 120 Bedouin men to elicit their views about the traditional Bedouin support system for the elderly (a collective family fund) and the more recent welfare support allowances that all Israeli elders are entitled to. Desire to maintain or return to the traditional system varied with the respondent's place on a continuum of seminomadism to rural sedentarization to semiurbanization. Differences were also found between the real Bedouin and the fellahim Bedouin respondents.


Asunto(s)
Anciano/psicología , Etnicidad , Apoyo Social , Bienestar Social , Actitud , Femenino , Humanos , Israel , Masculino , Arabia Saudita/etnología , Encuestas y Cuestionarios
14.
Trans Inst Br Geogr ; 11(2): 199-211, 1986.
Artículo en Inglés | MEDLINE | ID: mdl-12314312

RESUMEN

PIP: This paper proposes an adaptation of demographic transition theory to the nomadism-sedentarism continuum. It is argued that a change along this continuum implies a change in the mode of production, which in turn entails changes in fertility and mortality. The following hypotheses are set forth: 1) at the pastoral phase of a nomadic society, fertility is relatively low and mortality is relatively high, yielding a low rate of natural increase; 2) as a pastoral nomadic society senentarizes, fertility begins to rise and mortality falls, resulting in a sharp rise in natural increase, but as sedentarization becomes more advanced, both these trends slow down somewhat; 3) as the nomadic society becomes fully sedentarized, there is a period in which fertility remains at a high level but then begins to fall slowly, whereas mortality, after reaching a temporary minimum, exhibits a minor increase followed by a resumption of a declining trend; and 4) in the postsedentarization phase, the demographic regime of the ex-nomads becomes similar to the 2nd and 3rd stages of the original demographic transition theory, with a slowdown of the decline in mortality, followed by a later slowdown of fertility and of the rate of natural increase. The hypothesis of rising fertility among sedentarizing nomads is related to both social modernization and economic growth and development, including an improved standard of living and public health services. The interrelated processes of general societal responses to population growth and the changing role of children in the family are assumed to account for the eventual fertility decline. Data from several countries, including a case history from Israel, suggest that birth rates increase along the continuum but their decline at postsedentarization will depend on trends in the general rural sector. Natural increase rates of sedentarizing nomads are considerably higher than those of pastoral nomads. It is concluded that this approach may fill a gap in demographic transition theory and provide a conceptual framework for future studies.^ieng


Asunto(s)
Demografía , Países en Desarrollo , Economía , Emigración e Inmigración , Fertilidad , Modelos Teóricos , Mortalidad , Dinámica Poblacional , Crecimiento Demográfico , Población , Cambio Social , Planificación Social , Factores Socioeconómicos , Migrantes , África , Asia , Asia Occidental , Países Desarrollados , Servicios de Salud , Israel , Salud Pública , Investigación , Ciencias Sociales
15.
Hum Ecol ; 15(1): 91-107, 1987 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-12280855

RESUMEN

"This paper attempts to gather and present as much information as possible on crude birth and death rates and natural increase rates for various pastoral nomadic societies in different African and Middle Eastern countries. The information is arranged by a subdivision into nomads, seminomads, and sedentarized nomads. A summarization of this information suggests a possible pattern by which birth rates rise, death rates fall (but may rise in certain circumstances), and natural increase rates rise along the nomadism-sedentarism continuum. Such a possible pattern has several policy implications for governments assessing the needs of a nomadic society undergoing a process of change in its socio-ecological relationships."


Asunto(s)
Tasa de Natalidad , Emigración e Inmigración , Ambiente , Fertilidad , Mortalidad , Crecimiento Demográfico , Política Pública , Cambio Social , Migrantes , Estadísticas Vitales , África , Asia , Asia Occidental , Demografía , Países en Desarrollo , Población , Características de la Población , Dinámica Poblacional , Investigación
16.
Thromb Res ; 134(3): 639-42, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-25065557

RESUMEN

BACKGROUND: Heparanase is implicated in angiogenesis and tumor progression. We had earlier demonstrated that heparanase may also affect the hemostatic system in a non-enzymatic manner. It forms a complex and enhances the activity of the blood coagulation initiator- tissue factor (TF). Although increased heparanase antigen level in the plasma and biopsies of cancer patients was previously demonstrated, in the present study we evaluated, for the first time, the heparanase procoagulant activity in the plasma of patients with lung cancer. MATERIALS AND METHODS: Sixty five patients with non-small cell lung cancer at presentation and twenty controls were recruited. Plasma was studied for TF / heparanase procoagulant activity, TF activity and heparanase procoagulant activity using chromogenic assay and heparanase antigen levels by ELISA. RESULTS: Heparanase antigen levels were higher in the study group compared to control (P=0.05). TF / heparanase activity, and even more apparent, heparanase procoagulant activity were significantly higher in the study group compared to controls (P=0.008, P<0.0001, respectively). No significant difference was observed in the TF activity between the groups. Survival of patients with heparanase procoagulant activity higher than 31 ng/ml predicted a mean survival of 9 ± 1.3 months while heparanase procoagulant activity of 31 ng/ml or lower predicted a mean survival of 24 ± 4 months (P=0.001). Heparanase procoagulant activity was higher than 31 ng/ml in the four cases of thrombosis detected during the follow-up period. CONCLUSIONS: Elevated heparanase procoagulant activity in patients with lung cancer reveals a new mechanism of coagulation system activation in malignancy. Heparanase procoagulant activity can potentially be used as a predictor for survival.


Asunto(s)
Biomarcadores de Tumor/sangre , Coagulación Sanguínea , Carcinoma de Pulmón de Células no Pequeñas/enzimología , Glucuronidasa/sangre , Neoplasias Pulmonares/enzimología , Anciano , Carcinoma de Pulmón de Células no Pequeñas/sangre , Carcinoma de Pulmón de Células no Pequeñas/complicaciones , Carcinoma de Pulmón de Células no Pequeñas/mortalidad , Estudios de Casos y Controles , Femenino , Humanos , Estimación de Kaplan-Meier , Neoplasias Pulmonares/sangre , Neoplasias Pulmonares/complicaciones , Neoplasias Pulmonares/mortalidad , Masculino , Persona de Mediana Edad , Pronóstico , Factores de Riesgo , Trombosis/sangre , Trombosis/enzimología , Trombosis/etiología , Factores de Tiempo , Regulación hacia Arriba
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