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1.
J Endocrinol Invest ; 2023 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-37955834

RESUMO

AIM: Growth differentiation factor 15 (GDF15) is a stress response cytokine that has been proposed as a relevant metabolic hormone. Descriptive studies have shown that plasma GDF15 levels are regulated by short term changes in nutritional status, such as fasting, or in obesity. However, few data exist regarding how GDF15 levels are regulated in peripheral tissues. The aim of the present work was to study the variations on gastric levels of GDF15 and its precursor under different physiological conditions, such as short-term changes in nutritional status or overfeeding achieved by HFD. Moreover, we also address the sex- and age-dependent alterations in GDF15 physiology. METHODS: The levels of gastric and plasma GDF15 and its precursor were measured in lean and obese mice, rats and humans by western blot, RT-PCR, ELISA, immunohistochemistry and by an in vitro organ culture system. RESULTS: Our results show a robust regulation of gastric GDF15 production by fasting in rodents. In obesity an increase in GDF15 secretion from the stomach is reflected with an increase in circulating levels of GDF15 in rats and humans. Moreover, gastric GDF15 levels increase with age in both rats and humans. Finally, gastric GDF15 levels display sexual dimorphism, which could explain the difference in circulating GFD15 levels between males and females, observed in both humans and rodents. CONCLUSIONS: Our results provide clear evidence that gastric GDF15 is a critical contributor of circulating GDF15 levels and can explain some of the metabolic effects induced by GDF15.

2.
Med Oral Patol Oral Cir Bucal ; 24(5): e588-e594, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31433390

RESUMO

BACKGROUND: Determine the behavior of the maxillofacial trauma of adults treated in 3 tertiary care centers in the central zone of Chile. MATERIAL AND METHODS: descriptive, cross-sectional, multicenter study, based on the prospective records of maxillofacial trauma cases attended between May 2016 and April 2017 by dental and maxillofacial clinical teams of Adult Emergency Units of hospitals Dr. Sótero del Río (metropolitan region), Carlos Van Buren and Dr. Gustavo Fricke (region V). Age, sex, date of occurrence, type of trauma according to ICD-10, etiology, legal medical prognosis and associated injuries were recorded, stratifying by sex and age. Chi square and unpaired Wilcoxon tests were used to compare by groups. RESULTS: 2.485 cases and 3.285 injuries were investigated. The male: female ratio was 1.7: 1 with age under 30 predominant, followed by older adults. Variability was observed in the yearly, weekly and daily presentation. The highest frequencies were in January and September, weekends and at night. The main etiologies were violence (42.3%), falls (13.1%) and road traffic crashes (12.9%) with differences by age and sex (p <0.05). 31,9% of the injuries occurred in hard tissue, being fractures in nasal bones predominant (S02.2). CONCLUSIONS: the profile of the maxillofacial trauma in Chile seems to be mixed by age, affecting young people and the elderly. The male sex predominates; the main cause, which varies by age group, is violence. Their surveillance is possible from hospital emergency records.


Assuntos
Acidentes de Trânsito , Traumatismos Maxilofaciais , Adolescente , Idoso , Chile , Estudos Transversais , Feminino , Humanos , Masculino , Estudos Retrospectivos , Violência
3.
J Cell Biochem ; 117(2): 320-33, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26129689

RESUMO

The oviduct acts as a functional sperm reservoir in many mammalian species. Both binding and release of spermatozoa from the oviductal epithelium are mainly modulated by sperm capacitation. Several molecules from oviductal fluid are involved in the regulation of sperm function. Anandamide is a lipid mediator involved in reproductive physiology. Previously, we demonstrated that anandamide, through activation of the cannabinoid receptor type 1 (CB1), promotes sperm release from bovine oviductal epithelial cells, and through CB1 and the transient receptor potential vanilloid 1 (TRPV1), induces sperm capacitation. Herein we investigate co-activation between CB1 and TRPV1, and Ca(2+) influx as part of the mechanism of action of anandamide during sperm release from oviductal cells. Our results indicate that in the absence of Ca(2+) anandamide failed to release spermatozoa from oviductal epithelial cells. Additionally, sperm release promoted by cannabinoid and vanilloid agonists was abolished when the spermatozoa were preloaded with BAPTA-AM, a Ca(2+) chelator. We also determined Ca(2+) levels in spermatozoa preloaded with FURA2-AM co-cultured with oviductal cells and incubated with different cannabinoid and vanilloid agonists. The incubation with different agonists induced Ca(2+) influx, which was abolished by CB1 or TRPV1 antagonists. Our results also suggest that a phospholypase C (PLC) might mediate the activation of CB1 and TRPV1 in sperm release from the bovine oviduct. Therefore, our findings indicate that anandamide, through CB1 and TRPV1 activation, is involved in sperm release from the oviductal reservoir. An increase of sperm Ca(2+) levels and the PLC activation might be involved in anandamide signaling pathway.


Assuntos
Ácidos Araquidônicos/farmacologia , Agonistas de Receptores de Canabinoides/farmacologia , Endocanabinoides/farmacologia , Oviductos/metabolismo , Alcamidas Poli-Insaturadas/farmacologia , Receptor CB1 de Canabinoide/metabolismo , Canais de Cátion TRPV/metabolismo , Animais , Sinalização do Cálcio , Bovinos , Células Cultivadas , Técnicas de Cocultura , Feminino , Masculino , Oviductos/citologia , Capacitação Espermática
4.
J Ind Microbiol Biotechnol ; 38(9): 1203-9, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21104001

RESUMO

Purification and matrix-assisted refolding of recombinant His-tagged polyhydroxyalkanoate (PhaZ) depolymerase from Pseudomonas putida KT2442 was carried out. His-tagged enzyme was overproduced as inclusion bodies in recombinant E. coli M15 (pREP4, pPAZ3), which were denatured by 8 M urea, immobilized on Ni(2+)-nitrilotriacetate-agarose matrix, and refolded by gradual removal of the chaotropic agent. The refolded enzyme could not be eluted with 1 M imidazole buffer, leading to an immobilized biocatalyst where PhaZ depolymerase was homogeneously distributed in the agarose support as shown by confocal scanning microscopy. Polyhydroxyoctanoate could not be hydrolyzed by this novel immobilized biocatalyst, whereas the attached enzyme was active in the hydrolysis of p-nitrophenyl alkanoate esters, which differed in their alkyl chain length. Taking advantage of the observed esterase activity on p-nitrophenylacetate, functional characterization of immobilized PhaZ depolymerase was carried out. The immobilized enzyme was more stable than its soluble counterpart and showed optimal hydrolytic activity at 37°C and 50 mM phosphate buffer pH 8.0. Kinetic parameters were obtained with both p-nitrophenylacetate and p-nitrophenyloctanoate, which had not been described so far for the soluble enzyme, representing an attractive and alternative chromogenic assay for the study of this paradigmatic enzyme.


Assuntos
Hidrolases de Éster Carboxílico/metabolismo , Enzimas Imobilizadas/metabolismo , Corpos de Inclusão/enzimologia , Pseudomonas putida/enzimologia , Biocatálise , Hidrolases de Éster Carboxílico/química , Hidrolases de Éster Carboxílico/genética , Enzimas Imobilizadas/química , Enzimas Imobilizadas/genética , Escherichia coli/genética , Hidrólise , Redobramento de Proteína , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo
5.
Biodemography Soc Biol ; 66(2): 156-171, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34182852

RESUMO

Studies of the current Chilean population performed using classical genetic markers have established that the Chilean population originated primarily from the admixture of European people, particularly Spaniards, and Amerindians. A socioeconomic-ethno-genetic cline was established soon after the conquest. Spaniards born in Spain or Chile occupied the highest Socioeconomic Strata, while Amerindians belonged to the lowest. The intermediate strata consisted of people with different degrees of ethnic admixture; the larger the European admixture, the higher the Socioeconomic Level. The present study of molecular genomic markers sought to calculate the percentage of Amerindian admixture and revealed a finer distribution of this cline, as well as differences between two Amerindian groups: Aymara and Mapuche. The use of two socioeconomic classifications - Class and Socioeconomic Level - reveals important differences. Furthermore, Self-reported Ethnicity (self-assignment to an ethnic group) and Self-reported Ancestry (self-recognition of Amerindian ancestors) show variations and differing relationships between socioeconomic classifications and genomic Amerindian Admixture. These data constitute a valuable input for the formulation of public healthcare policy and show that the notions of Ethnicity, Socioeconomic Strata and Class should always be a consideration in policy development.


Assuntos
Etnicidade , Genômica , Chile , Frequência do Gene , Marcadores Genéticos , Humanos , Indígenas Sul-Americanos/genética , Espanha
6.
Prostaglandins Other Lipid Mediat ; 80(3-4): 155-64, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16939880

RESUMO

We investigated the regulation of cyclooxygenase-2 (COX-2) by 17-beta-estradiol (E2) in the rat oviduct. We observed that COX-2 is expressed mainly in proestrous and estrous stages, periods under estrogenic influence. While exogenous administration of E2 (1 microg/rat) significantly increased COX-2 protein levels, progesterone did not modify it. COX-2 was mainly localized on oviductal epithelial cells from estrogenized rat. Induction of COX-2 expression by E2 was partially reverted by tamoxifen (1 mg/rat), an E2 receptor antagonist. Estradiol treatment also increased prostaglandins (PGs) synthesis: 6-keto-PGF(1alpha) (40%), a stable metabolite of prostacyclin (PGI2), PGF(2alpha) (40%) and PGE2 (50%). Tamoxifen completely suppressed this enhancement. In order to discriminate which isoform of COX was implicated in the stimulatory effect of E2 on PGs synthesis, oviducts were preincubated with meloxicam (Melo: 10(-9)M) or NS-398 (10(-7)M), two selective COX-2 inhibitors. Both Melo and NS-398 abolished the increase of PGs synthesis stimulated by E2. All together, these data indicate that E2 could upregulate COX-2 expression and activity in the rat oviduct and that the stimulatory effect of E2 may be receptor-mediated.


Assuntos
Ciclo-Oxigenase 2/metabolismo , Estradiol/farmacologia , Oviductos/efeitos dos fármacos , Oviductos/enzimologia , Animais , Ciclo-Oxigenase 1/metabolismo , Ciclo-Oxigenase 2/análise , Inibidores de Ciclo-Oxigenase 2/farmacologia , Epitélio/efeitos dos fármacos , Epitélio/enzimologia , Ciclo Estral/metabolismo , Feminino , Imuno-Histoquímica , Meloxicam , Proteínas de Membrana/metabolismo , Nitrobenzenos/farmacologia , Oviductos/metabolismo , Gravidez , Progesterona/farmacologia , Prostaglandinas/biossíntese , Ratos , Ratos Wistar , Receptores de Estradiol/antagonistas & inibidores , Sulfonamidas/farmacologia , Tamoxifeno/farmacologia , Tiazinas/farmacologia , Tiazóis/farmacologia , Regulação para Cima/efeitos dos fármacos
7.
Biochim Biophys Acta ; 1368(1): 27-34, 1998 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-9459581

RESUMO

The size and ionic selectivity of the pores formed by the insecticidal crystal protein Cry1C from Bacillus thuringiensis in the plasma membrane of Sf9 cells, an established cell line derived from the fall armyworm Spodoptera frugiperda, were analyzed with a video imaging technique. Changes in the permeability of the membrane were estimated from the rate of osmotic swelling of the cells. In the presence of Cry1C, which is toxic to Sf9 cells, the permeability of the cell membrane to KCl and glucose increased in a dose-dependent manner. In contrast, Cry1Aa, Cry1Ab and Cry1Ac, toxins to which Sf9 cells are not susceptible, had no detectable effect. Pores formed by Cry1C allowed the diffusion of sucrose, but were impermeable to the trisaccharide raffinose. On the basis of the hydrodynamic radii of these substances, the diameter of the pores was estimated to be 1.0-1.2 nm. In the presence of salts, the rate of swelling of cells exposed to Cry1C was about equally influenced by the size of the anion as by that of the cation, indicating that the ionic selectivity of the pores is low.


Assuntos
Bacillus thuringiensis/metabolismo , Proteínas de Bactérias/farmacologia , Toxinas Bacterianas , Endotoxinas/farmacologia , Spodoptera/efeitos dos fármacos , Animais , Toxinas de Bacillus thuringiensis , Linhagem Celular , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Permeabilidade da Membrana Celular , Proteínas Hemolisinas , Canais Iônicos/metabolismo , Concentração Osmolar , Spodoptera/metabolismo , Sacarose/metabolismo , Gravação de Videoteipe
8.
Placenta ; 26(10): 758-65, 2005 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-16226126

RESUMO

Many authors hypothesize that the epidermal growth factor (EGF) is involved in the onset of labor. Previous reports from our laboratory showed that intrauterine administration of EGF delays the beginning of labor. The aims of this study were: 1) to analyze the effect of intrauterine administration of 500 ng EGF on placental prostaglandins and nitric oxide, and 2) to characterize the expression of EGF receptors (EGF-R) in pregnant rat placentae. Saline solution (sham group) and 500 ng EGF (EGF-treated group) were administered via intrauterine injection on day 21 of gestation, and both groups of animals were sacrificed on day 22 (sham rats delivered on day 22). Results showed that EGF treatment: 1) inhibited the production of prostaglandin E (p<0.001) and F(2alpha) (p<0.01), 2) increased the synthesis of nitric oxide (p<0.001), and 3) reduced the expression of cyclooxygenase-II, the enzyme responsible for PG synthesis. Placentae were found to express EGF-R and its activated form, and the expressions of both forms were higher at mid and term pregnancy. Hence, EGF is a very interesting molecule for studying the regulation of placental prostaglandin and nitric oxide production related to the parturition process.


Assuntos
Dinoprosta/biossíntese , Fator de Crescimento Epidérmico/farmacologia , Receptores ErbB/metabolismo , Óxido Nítrico Sintase/metabolismo , Placenta/efeitos dos fármacos , Placenta/metabolismo , Prostaglandinas E/biossíntese , Animais , Western Blotting , Ciclo-Oxigenase 2/biossíntese , Receptores ErbB/biossíntese , Feminino , Isoenzimas , Óxido Nítrico/biossíntese , Óxido Nítrico Sintase/biossíntese , Placenta/enzimologia , Gravidez , Ratos
9.
Food Chem ; 171: 266-71, 2015 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-25308668

RESUMO

Recent studies have shown that it should be possible to control lipid bioavailability through food structural approaches. Nevertheless, the gastrointestinal-tract physiological conditions must also be considered. To get a better understanding of this phenomenon, we evaluated the effect of emulsification, as well as the use of sodium caseinate or chitosan, on the postprandial bioavailability of interesterified-lipids in O/W emulsions after oral gastric feeding Sprague-Dawley rats. We verified that emulsification may increase lipid absorption, as determined after feeding sodium-caseinate emulsions. However, this result could not be generalised. Interesterified-lipids that were emulsified with chitosan were equally absorbed as those contained in non-emulsified interesterified-lipids/distilled-water blends.


Assuntos
Biomarcadores/sangue , Caseínas/química , Quitosana/química , Emulsões/química , Lipídeos/química , Animais , Disponibilidade Biológica , Masculino , Ciências da Nutrição , Período Pós-Prandial , Ratos , Ratos Sprague-Dawley , Reologia , Água/química
10.
Neotrop Entomol ; 44(6): 565-73, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26371365

RESUMO

An analysis of adult population fluctuation of Anastrepha ludens (Loew) was performed in southern Tamaulipas, Mexico from 2008 to 2011. The aim was to analyze population dynamics of A. ludens and its relationships with climatic factors in the citrus region of Llera, Tamaulipas, Mexico. Population densities were weekly examined to identify variation through the year and study period. Four periods were identified according to population size, amplitude, host availability and season of the year. The correlation between population density vs. rainfall and temperature (average, minimum and maximum) was determined by linear and multiple regression analyses. Simple linear regression analysis showed that population density with minimum temperature and rainfall was the most consistent correlation, whereas in multiple regression analysis, rainfall and maximum temperature showed more consistency. A seasonal association between the availability of commercial host, climatic variation, and population peaks of A. ludens was determined. This study may have practical implications for the design of specific control strategies, monitoring, and infestation prevention based on different phases of the pest through the year. This strategy, along with the area-wide approach implemented by the Plant Protection Service may lead to an optimization of material, financial and human resources.


Assuntos
Citrus , Tephritidae/crescimento & desenvolvimento , Animais , México , Densidade Demográfica , Dinâmica Populacional
11.
Eur J Cell Biol ; 74(1): 1-9, 1997 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-9309385

RESUMO

Gap junctions in epithelial cells of the oviduct were identified by immunohistochemistry and Western blotting. Immunohistochemical studies showed that rat, hamster, mouse, and human oviducts contained connexin26 and connexin43 but not connexin32. The content of both connexins in the oviduct depended on the cell type, state of maturation and hormone status. During ontogeny, the epithelial and smooth muscle cells of immature rat oviducts (< 30 days) contained a low amount of connexin43, and connexin26 was undetectable. In mature oviducts (> 30 days), however, connexin26 was detected only in the isthmus and in localized regions of the ampullar epithelial layer. Moreover, at this age, the amount of connexin43 was high in both cell strata throughout the entire organ. During the estrous cycle, levels of connexin43 in the isthmic but not in the ampullar segment were higher in the proestrous and estrous day than at diestrous days. In addition, estrogen treatment produced a significant increase in total and phosphorylated isoforms of connexin43 levels in oviducts of pregnant rats. The estrogen effect was prevented by the simultaneous administration of progesterone which by itself did not affect the levels of connexin43. The high content of connexins found between oviductal cells as well as their responsiveness to hormone regulation, suggest that gap junctions might be involved in coordinating oviductal cell functions such as smooth muscle contraction and epithelial ciliary beat.


Assuntos
Conexinas/análise , Estradiol/farmacologia , Tubas Uterinas/química , Tubas Uterinas/crescimento & desenvolvimento , Junções Comunicantes/fisiologia , Progesterona/farmacologia , Animais , Conexina 26 , Cricetinae , Células Epiteliais/química , Estro/fisiologia , Tubas Uterinas/citologia , Feminino , Humanos , Camundongos , Músculo Liso/química , Músculo Liso/citologia , Gravidez , Ratos , Ratos Sprague-Dawley
12.
Antiviral Res ; 20(2): 131-44, 1993 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-8460931

RESUMO

Several inhibitors of S-adenosylhomocysteine (AdoHcy) hydrolase have been found to selectively suppress the replication of African swine fever virus (ASFV) in Vero cells. Of the compounds tested, 3-deazaneplanocin A proved to be the most potent and selective inhibitor of ASFV replication. Its selectivity index (SI) was 3000. Then followed 9-(trans-2',trans-3'-dihydroxycyclopentyl)-3- deazaadenine (SI = 2500), the 4'beta-vinyl derivative of 9-(trans-2',trans-3'-dihydroxycyclopentyl)adenine (SI = 2000), 6'beta-fluoroaristeromycin (SI = 1250), 4',5'-unsaturated 5'-fluoroadenosine (MDL 28842) and 9-(trans-2',trans-3'-dihydroxycyclopentyl)adenine (SI = 667), 9-(trans-2',trans-3'-dihydroxycyclopent-4'-enyl)adenine and the 4 beta-methyl derivative of 9-(trans-2',trans-3'- dihydroxycyclopentyl)adenine (SI = 400), 9-(trans-2',trans-3'-dihydroxycyclopent-4'-enyl)-3-deazaadenine (SI = 200). We postulate that the mechanism of anti-ASFV action of these compounds is based on the inhibition of AdoHcy hydrolase, thus resulting in the accumulation of AdoHcy and suppression of methylation reactions needed for viral mRNA maturation.


Assuntos
Vírus da Febre Suína Africana/efeitos dos fármacos , Antivirais/farmacologia , Hidrolases/antagonistas & inibidores , Replicação Viral/efeitos dos fármacos , Adenosil-Homocisteinase , Vírus da Febre Suína Africana/fisiologia , Animais , Sobrevivência Celular/efeitos dos fármacos , Efeito Citopatogênico Viral/efeitos dos fármacos , RNA Viral/biossíntese , Relação Estrutura-Atividade , Células Vero , Ensaio de Placa Viral
13.
Hematol J ; 1(4): 269-73, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-11920201

RESUMO

INTRODUCTION: Recently, the common Val34Leu polymorphism of the A-chain factor XIII gene, associated with high factor XIII activity, has been identified as a protective genetic factor against occlusive arterial and venous diseases. Moreover, this polymorphism has been suggested to be the first one to increase the risk of cerebral haemorrhage in a small number of Caucasian patients. The aim of our study was to investigate the role of this polymorphism in patients with primary intracerebral haemorrhage from a distinct population. MATERIAL AND METHODS: Patients with non-traumatic primary intracerebral haemorrhage (n=116), age-, race-, sex- and risk factor-matched controls (n=116), and individuals from the general population (n=465) were genotyped for the factor XIII Val34Leu polymorphism by polymerase chain reaction and allele specific restriction assay. The relationships of the Val/Leu genotype with distinct intracerebral haemorrhagic risk factors and with early mortality associated with the haemorrhagic episode were also analysed. RESULTS: No statistical difference in terms of prevalence was detected between patients (P=0.190) and controls (P=0.181). The frequency of the FXIII Leu34 allele was similar in the general population (P=0.191). CONCLUSION: The results suggest that the Leu 34 allele of the A-chain factor XIII gene has a minor role in the development of non-traumatic primary intracerebral haemorrhage. Moreover, the simultaneous presence of the Leu 34 allele with selected risk factors for this disease does not increase the risk of developing this disease.


Assuntos
Hemorragia Cerebral/genética , Fator XIII/genética , Idoso , Idoso de 80 Anos ou mais , Consumo de Bebidas Alcoólicas/epidemiologia , Substituição de Aminoácidos , Estudos de Casos e Controles , Códon/genética , Análise Mutacional de DNA , Ativação Enzimática , Fator XIII/fisiologia , Feminino , Frequência do Gene , Predisposição Genética para Doença , Genótipo , Humanos , Hipertensão/epidemiologia , Masculino , Pessoa de Meia-Idade , Polimorfismo Genético , Fatores de Risco , Fumar/epidemiologia , Espanha/epidemiologia , População Branca/genética
14.
Fertil Steril ; 46(3): 412-6, 1986 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-3488922

RESUMO

Women who have Kartagener's syndrome (primary ciliary dyskinesia) may or may not be fertile. The bronchial mucociliary clearance is reduced markedly in most of these women; this has led investigators to the conclusion that the cilia in the respiratory tract are immotile, and that "beating cilia may have no indispensable role in the female reproductive tract." Yet motile cilia are considered by many workers to be essential for normal ovum transport. More recently, bizarre ciliary motion has been described in the respiratory cilia of Kartagener's women. Our hypothesis was that the dyskinetic ciliary activity (or immotility) would be the same in both the respiratory and reproductive tracts and thus explain the fertility (or lack of it) in Kartagener's women. This report shows an identical ultrastructure and absolute immotility of cilia in both the respiratory tract and reproductive tract of a woman with Kartagener's syndrome who has never conceived. From this concordance, we suggest that the fertility of Kartagener's women is explained by the dyskinetic motion of oviductal cilia, and that the ciliated endosalpinx is essential for human reproduction.


Assuntos
Tubas Uterinas/ultraestrutura , Síndrome de Kartagener/patologia , Adulto , Cílios/fisiopatologia , Cílios/ultraestrutura , Tubas Uterinas/fisiopatologia , Feminino , Humanos , Infertilidade Feminina/etiologia , Síndrome de Kartagener/complicações , Síndrome de Kartagener/fisiopatologia , Gravidez
15.
J Dent Res ; 66(2): 506-8, 1987 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-3476567

RESUMO

Mucus is an ubiquitous polymer hydrogel that functions as a protective coat on the surface of integument and mucosa of species ranging from simple animals (such as coelenterates) to mammals. The polymer matrix of mucus is made out of long-chain glycoproteins called mucins that are tangled together, forming a randomly woven, highly polyionic network (Lee et al., 1977; Verdugo et al., 1983). Mucin-containing granules, produced by mammalian goblet cells in vitro, undergo massive post-exocytotic swelling. Their swelling kinetics is similar to the swelling of condensed artificial polymer gels (Verdugo, 1984; Tanaka and Fillmore, 1979). We had proposed that mucins must be condensed in the secretory granule and expand by hydration during or after exocytosis (Verdugo, 1984; Tam and Verdugo, 1981). However, the polyionic charges of mucins prevents condensation unless they (the mucins) are appropriately shielded. The present experiments were designed to assert the presence of an intragranular shielding cation and its role in secretion. Giant mucin granules of the slug (Ariolimax columbianus) are released intact from mucus-secreting cells of the slug's skin. They burst spontaneously outside the cell, forming, upon hydration, the typical slug mucus (Deyrup-Olsen et al., 1983). We report here that these granules contain from 2.5 to 3.6 moles calcium/kg dry material, and that calcium is released from the granules immediately before the burst that discharges their secretory product. Therefore, we propose that calcium functions as a shielding cation of polyionic mucins, and that the bursting discharge of mucins from secretory granules must result from the release of calcium from the intragranular compartment.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Cálcio/fisiologia , Grânulos Citoplasmáticos/fisiologia , Mucinas/metabolismo , Animais , Cálcio/análise , Fenômenos Químicos , Físico-Química , Grânulos Citoplasmáticos/ultraestrutura , Microanálise por Sonda Eletrônica , Eletrofisiologia , Microscopia Eletrônica de Varredura , Caramujos
16.
Biorheology ; 27(3-4): 465-70, 1990.
Artigo em Inglês | MEDLINE | ID: mdl-2261512

RESUMO

Mucins, are densely packed in secretory granules of goblet cells. Upon exocytosis they undergo massive hydration that results in the formation of the mucus gel. Because the mucin polymer network is held together by tangles and low energy bonds, the rheological properties of this gel are mainly determined by the degree of postexocytotic hydration. Hydration in mucus is governed by a Donnan equilibrium as it is driven by electrostatic interaction among the polyionic charges of the mucins and other fixed polyions. Although, variations of charge density of the mucin polymer could be an efficient physiologic mechanism to control the rate of mucus hydration and rheology, this subject has not been investigated. In here we describe a primary tissue culture system of cervical goblet cells of the monkey uterus. This preparation allows to measure directly the kinetic of hydration of exocytosed mucins. Because the physicochemical parameters of the bathing medium can be effectively controlled, variations in the kinetic of mucins swelling upon exocytosis, can be used as a convenient indicator of fluctuations of charge density in secretory products. Since the cervical mucosa readily respond to endocrine influences, this preparation can provide a useful model to study the effect of hormones or other transmitters on polyionic charge density of secretory product.


Assuntos
Colo do Útero/metabolismo , Exocitose/fisiologia , Modelos Biológicos , Mucinas/fisiologia , Mucosa/citologia , Animais , Colo do Útero/citologia , Técnicas de Cultura/métodos , Feminino , Macaca nemestrina , Gravação em Vídeo
17.
Biorheology ; 24(6): 625-33, 1987.
Artigo em Inglês | MEDLINE | ID: mdl-3502764

RESUMO

Mucin-containing granules, produced by mammalian goblet cells in vitro, undergo massive post-exocytotic swelling (23). Their swelling kinetics are similar to the swelling of condensed artificial polymer gels (22). Earlier, we proposed that mucins are condensed in the secretory granule and expand by swelling during or after exocytosis (21). The swelling of mucus is affected by ionic influences, as it is governed by a Donnan equilibrium process (21). However, the effect of cations on the swelling of newly released mucins had not yet been investigated. Calcium has been found in high concentration inside secretory granules of mucin-secreting cells (18, 9, 25), and is also elevated in the mucus of cystic fibrosis patients (17). The present experiments were designed to study the effect of extracellular Ca++ concentration on the swelling kinetics of the newly released secretory product of respiratory goblet cells in vitro. The data show that extracellular Ca++, in concentrations similar to those found in the mucus of cystic fibrosis patients (2 to 4 mM) can produce a four-fold decrease in the diffusivity of the newly released mucin polymer network, resulting in a slow rate of swelling, and a mucus that remains thick for long periods of time. The present findings are in agreement with the Donnan equilibrium hypothesis for the regulation of mucus swelling and rheology (21), and bear important implications for the pathophysiology of cystic fibrosis.


Assuntos
Cálcio/fisiologia , Mucinas/metabolismo , Animais , Técnicas de Cultura , Muco/metabolismo , Coelhos , Traqueia/efeitos dos fármacos , Traqueia/metabolismo
18.
Arch Latinoam Nutr ; 31(4): 766-81, 1981 Dec.
Artigo em Espanhol | MEDLINE | ID: mdl-7347166

RESUMO

In order to evaluate the influence of breast feeding upon selected nutritional parameters of lactating women, several anthropometric and biochemical measurements were performed during the interval between 40 and 180 postpartum days in 54 women in full and satisfactory nursing. Only one significant change was detected in measurements done for nutritional assessment: loss of body weight. No changes were detected in hemoglobin levels or in serum protein and albumin. There was high variability in body weight changes with a mean loss of 1.5 kg due especially to a loss in fat body mass and, in a lesser proportion, to loss in lean body mass. The mean food intake did not change during the observation period. The mean caloric intake was 2,771 cal/day at the beginning and 2,737 cal/day in the end of the study. A significant correlation was established between the individual energetic intake and the body weight changes of lactating women. The allowance of 2,750 cal/day suggested by FAO/WHO for lactating women seems adequate for the health of women in a normal nutritional condition, but apparently insufficient to overcome undernutrition in women who initiate lactation with this condition. In spite of the small nutritional impact observed, our results support the need for food supplementation programs destined to lactating women, with special orientation to undernourished women of low socioeconomic level.


Assuntos
Dieta , Ingestão de Energia , Lactação , Fenômenos Fisiológicos da Nutrição , Adolescente , Adulto , Proteínas Sanguíneas/análise , Estatura , Peso Corporal , Feminino , Hemoglobinas/análise , Humanos , Gravidez , Albumina Sérica/análise
19.
Rev. chil. cir ; 71(1): 55-60, feb. 2019. tab
Artigo em Espanhol | LILACS | ID: biblio-985379

RESUMO

Resumen Introducción: El cáncer colorrectal se ha convertido en el tercer cáncer a nivel mundial en cuanto a incidencia y cuarto en mortalidad. Al diagnóstico, aproximadamente el 25% de los pacientes tendrán metástasis hepáticas. Con tratamiento adecuado el pronóstico de los pacientes etapa IV alcanza una sobrevida de 40% a 5 años. Con nuestro trabajo queremos evaluar la respuesta del tumor primario de colon desde el punto de vista imagenológico y anatomopatológico en pacientes con cáncer colorrectal con metástasis hepáticas tratados con quimioterapia y que luego fueron a resección del colon. Materiales y Método: Se trata un estudio retrospectivo y descriptivo, de pacientes con cáncer colorrectal con metástasis hepáticas. Los criterios de inclusión fueron que presentaran cáncer de colon o recto superior, con metástasis hepáticas sincrónicas, recibieran al menos 4 ciclos de quimioterapia neoadyuvante y que posteriormente fueran a resección del tumor primario. Resultados: Se reclutaron 9 pacientes, 4 hombres y 5 mujeres. Todos recibieron 4 o más ciclos de quimioterapia previo a la cirugía del tumor primario. De ellos, 8 tuvieron control imagenológico posquimioterapia. Según criterios RECIST, 3 pacientes presentaron respuesta completa, 1 paciente respuesta parcial y 4 enfermedad estable. El estudio anatomopatológico del colon resecado mostró desaparición tumoral macroscópica en 2 pacientes y microscópica en 1 paciente. Conclusiones: La regresión patológica completa en nuestros casos tratados con quimioterapia neoadyuvante es un hecho poco frecuente. Esto nos permite indicar la resección del sitio del tumor colorrectal en todos estos casos.


Introduction: Colorectal cancer has become the third cancer worldwide in terms of incidence and fourth in mortality. At diagnosis approximately 25% of patients will have liver metastases. With adequate treatment, the prognosis of stage IV patients reaches a survival of 40% at 5 years. We want to evaluate the response of the primary tumor of the colon from imaging and anatomopathological point of view in patients with colorectal cancer with liver metastases treated with chemotherapy and who then went to colon resection. Materials and Method: It is a retrospective and descriptive study of patients with stage IV colorectal cancer. The inclusion criteria were that they had cancer of the colon or upper rectum, with synchronous liver metastases, who have received at least 4 cycles of neoadjuvant chemotherapy and that subsequently went to resection of the primary tumor. Results: We recruited 9 patients, 4 men and 5 women. All received 4 or more cycles of chemotherapy prior to primary surgery. Of these, 8 had imaging control after chemotherapy. According to RECIST criteria, 3 patients presented complete response, 1 patient partial response and 4 stable disease. The anatomopathological study of the resected colon showed a macroscopic tumor disappearance in 2 patients, and microscopic in 1 patient. Conclusions: The complete pathological regression in our cases treated with neoadjuvant chemotherapy is a rare occurrence. This allows us to indicate the resection of the colorectal tumor site in all these cases.


Assuntos
Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Idoso , Neoplasias Colorretais/cirurgia , Neoplasias Colorretais/radioterapia , Neoplasias Hepáticas/secundário , Metástase Neoplásica , Neoplasias Colorretais/mortalidade , Taxa de Sobrevida , Intervalo Livre de Doença , Estadiamento de Neoplasias
20.
Rev. cir. (Impr.) ; 71(3): 225-229, jun. 2019. tab
Artigo em Espanhol | LILACS | ID: biblio-1058261

RESUMO

INTRODUCCIÓN: En la endometriosis el compromiso intestinal afecta hasta al 12% de las pacientes, comprometiendo al recto y a la unión rectosigmoidea en el 90% de los casos. OBJETIVO: Describir la experiencia del equipo de Coloproctología y Ginecología de Clínica Alemana de Santiago en el tratamiento quirúrgico de la endometriosis pélvica profunda con compromiso colorrectal. MATERIAL Y MÉTODOS: Estudio retrospectivo a partir de la base de datos de pacientes con endometriosis tratados entre enero del año 2015 y abril de 2018. Los criterios de inclusión fueron pacientes con clínica de endometriosis pélvica profunda, que tuviesen compromiso colorrectal y hayan sido tratados con shaving rectal, resección discoide o resección segmentaria. Se revisaron fichas clínicas electrónicas, protocolos operatorios y biopsias definitivas. RESULTADOS: Se reclutaron 25 pacientes con una mediana de edad de 35 años. El síntoma principal de consulta fue dismenorrea y el síntoma digestivo más frecuente fue disquecia. En 8 pacientes se realizó un shaving rectal, en 7 una sigmoidectomía, en 9 una resección discoide y en 1 paciente una tiflectomía. La complicación posoperatoria reportada fue la hemorragia digestiva baja en 4 pacientes (Clavien-Dindo I y IIIa). Con una mediana de seguimiento de 13 meses, a la fecha 3 pacientes se les ha diagnosticado algún tipo de recidiva. CONCLUSIÓN: Es importante que la cirugía a realizar, garantice una morbilidad y recurrencia baja. Los resultados en nuestro centro son alentadores, lo que nos hace creer que el tratamiento quirúrgico podría ser una buena alternativa en la endometriosis pélvica profunda con compromiso colorrectal.


INTRODUCTION: In endometriosis, intestinal involvement affects up to 12% of patients, compromising the rectum and the rectosigmoid junction in 90% of cases. AIM: Describe the experience of the Coloproctolgy and Gynecology Team of the Clínica Alemana de Santiago in the surgical treatment of deep pelvic endometriosis with colorectal involvement. MATERIAL AND METHODS: Retrospective study based on the database of patients with endometriosis treated between January 2015 and April 2018. The inclusion criteria were patients with deep pelvic endometriosis clinic, who had colorectal involvement and who had been treated with rectal shaving, discoid resection or segmental resection. Electronic clinical records, operative protocols and definitive biopsies were reviewed. RESULTS: Twenty-five patients with a median age of 35 years were recruited. The main symptom of consultation was dysmenorrhoea and the most frequent digestive symptom was dyschezia. In 8 patients a rectal shaving was performed, in 7 a sigmoidectomy, in 9 a discoid resection and in 1 patient a tiflectomy. The only reported post-operative complication was low gastrointestinal bleeding in 4 of the 25 patients (Clavien-Dindo I and IIIa). A median follow-up of 13 months was achieved, to date 3 patients have been diagnosed with some type of recurrence. CONCLUSION: It is important that the surgery to be performed guarantees low morbidity and recurrence. The results in our center are encouraging, which makes us believe that surgical treatment could be a good alternative in deep pelvic endometriosis with colorectal involvement.


Assuntos
Humanos , Feminino , Adulto , Pessoa de Meia-Idade , Pelve/patologia , Procedimentos Cirúrgicos do Sistema Digestório/métodos , Endometriose/cirurgia , Endometriose/complicações , Doenças Retais/cirurgia , Doenças Retais/etiologia , Recidiva , Estudos Retrospectivos , Seguimentos , Doenças do Colo/cirurgia , Doenças do Colo/etiologia , Endometriose/patologia , Tempo de Internação
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