Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 19 de 19
Filtrar
Más filtros

Bases de datos
País/Región como asunto
Tipo del documento
Asunto de la revista
Intervalo de año de publicación
1.
Ann Rheum Dis ; 73(12): 2160-7, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23965844

RESUMEN

OBJECTIVE: To evaluate the genetic findings, demographic features and clinical presentation of tumour necrosis factor receptor-associated autoinflammatory syndrome (TRAPS) in patients from the Eurofever/EUROTRAPS international registry. METHODS: A web-based registry collected retrospective data on patients with TNFRSF1A sequence variants and inflammatory symptoms. Participating hospitals included paediatric rheumatology centres and adult centres with a specific interest in autoinflammatory diseases. Cases were independently validated by experts in the disease. RESULTS: Complete information on 158 validated patients was available. The most common TNFRSF1A variant was R92Q (34% of cases), followed by T50M (10%). Cysteine residues were disrupted in 27% of cases, accounting for 39% of sequence variants. A family history was present in 19% of patients with R92Q and 64% of those with other variants. The median age at which symptoms began was 4.3 years but 9.1% of patients presented after 30 years of age. Attacks were recurrent in 88% and the commonest features associated with the pathogenic variants were fever (88%), limb pain (85%), abdominal pain (74%), rash (63%) and eye manifestations (45%). Disease associated with R92Q presented slightly later at a median of 5.7 years with significantly less rash or eye signs and more headaches. Children were more likely than adults to present with lymphadenopathy, periorbital oedema and abdominal pains. AA amyloidosis has developed in 16 (10%) patients at a median age of 43 years. CONCLUSIONS: In this, the largest reported case series to date, the genetic heterogeneity of TRAPS is accompanied by a variable phenotype at presentation. Patients had a median 70 symptomatic days a year, with fever, limb and abdominal pain and rash the commonest symptoms. Overall, there is little evidence of a significant effect of age or genotype on disease features at presentation.


Asunto(s)
Enfermedades Autoinflamatorias Hereditarias/genética , Receptores Tipo I de Factores de Necrosis Tumoral/genética , Adolescente , Adulto , Anciano , Niño , Preescolar , Estudios de Cohortes , Progresión de la Enfermedad , Exantema/etiología , Femenino , Fiebre/etiología , Genotipo , Enfermedades Autoinflamatorias Hereditarias/complicaciones , Enfermedades Autoinflamatorias Hereditarias/fisiopatología , Humanos , Masculino , Persona de Mediana Edad , Dolor/etiología , Fenotipo , Sistema de Registros , Estudios Retrospectivos , Factores de Tiempo , Adulto Joven
2.
Pediatr Rheumatol Online J ; 22(1): 55, 2024 May 17.
Artículo en Inglés | MEDLINE | ID: mdl-38760816

RESUMEN

BACKGROUND: Systemic autoinflammatory disorders (SAIDs) represent a growing spectrum of diseases characterized by dysregulation of the innate immune system. The most common pediatric autoinflammatory fever syndrome, Periodic Fever, Aphthous Stomatitis, Pharyngitis, Adenitis (PFAPA), has well defined clinical diagnostic criteria, but there is a subset of patients who do not meet these criteria and are classified as undefined autoinflammatory diseases (uAID). This project, endorsed by PRES, supported by the EMERGE fellowship program, aimed to analyze the evolution of symptoms in recurrent fevers without molecular diagnosis in the context of undifferentiated AIDs, focusing on PFAPA and syndrome of undifferentiated recurrent fever (SURF), using data from European AID registries. METHODS: Data of patients with PFAPA, SURF and uSAID were collected from 3 registries including detailed epidemiological, demographic and clinical data, results of the genetic testing and additional laboratory investigations with retrospective application of the modified Marshall and PRINTO/Eurofever classification criteria on the cohort of PFAPA patients and preliminary SURF criteria on uSAID/SURF patients. RESULTS: Clinical presentation of PFAPA is variable and some patients did not fit the conventional PFAPA criteria and exhibit different symptoms. Some patients did not meet the criteria for either PFAPA or SURF, highlighting the heterogeneity within these groups. The study also explored potential overlaps between PFAPA and SURF/uAID, revealing that some patients exhibited symptoms characteristic of both conditions, emphasizing the need for more precise classification criteria. CONCLUSIONS: Patients with recurrent fevers without molecular diagnoses represent a clinically heterogeneous group. Improved classification criteria are needed for both PFAPA and SURF/uAID to accurately identify and manage these patients, ultimately improving clinical outcomes.


Asunto(s)
Enfermedades Autoinflamatorias Hereditarias , Linfadenitis , Faringitis , Sistema de Registros , Estomatitis Aftosa , Humanos , Niño , Europa (Continente)/epidemiología , Femenino , Masculino , Estomatitis Aftosa/diagnóstico , Estomatitis Aftosa/epidemiología , Preescolar , Enfermedades Autoinflamatorias Hereditarias/diagnóstico , Linfadenitis/diagnóstico , Linfadenitis/epidemiología , Faringitis/diagnóstico , Adolescente , Lactante , Estudios Retrospectivos , Fiebre/etiología , Fiebre/diagnóstico , Recurrencia
3.
Klin Padiatr ; 225(6): 325-30, 2013 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-24158885

RESUMEN

Familial Mediterranean fever (FMF) is the most inherited common autoinflammatory disease (AID) with mutations in the MEFV (MEditerraneanFeVer) gene.The Mor- and Pras-Score modified for children and C-reactive protein (CRP) were used to assess FMF disease severity in Germany. We evaluate the applicability of the 2 severity scores and the correlations between ethnic origin, phenotype, and genotype.Among 242 children (median 5 age at diagnosis), we detected 431 pyrin mutations and 22 different sequence variants, including one new mutation (p.Gly488Asp). The 5 most -frequent alterations were p.Met694Val (55.2%), p.Met680lle (11.8%), p.Val726Ala (10%), p.Glu148Gln (7.9%) and p.Met694IIe (2.3%). The prevailing ancestries of 223 cases were Turkish (82.5%) and Lebanese (8.1%). Homozygous p.Met694Val substitution (30.2%) was associated with a more severe disease activity by Mor-Score, as well as with a higher mean CRP (74 mg/l) compared to patients with other mutations. Indeed, Mor- and Pras-Score were inconsistent with each other. A typical distribution of mutations in different ethnic populations was obvious, but not statistically verifiable due to the low number of cases.The homozygous p.Met694Val substitution was associated with a more severe disease activity in our German cohort. The common severity scores were inconsistent in -children.


Asunto(s)
Fiebre Mediterránea Familiar/diagnóstico , Fiebre Mediterránea Familiar/genética , Genotipo , Fenotipo , Adolescente , Alelos , Sustitución de Aminoácidos/genética , Proteína C-Reactiva/metabolismo , Niño , Preescolar , Estudios de Cohortes , Proteínas del Citoesqueleto/genética , Análisis Mutacional de ADN , Fiebre Mediterránea Familiar/etnología , Femenino , Frecuencia de los Genes/genética , Alemania , Homocigoto , Humanos , Lactante , Líbano/etnología , Masculino , Metionina/genética , Pirina , Sistema de Registros , Turquía/etnología , Valina/genética
4.
Science ; 262(5132): 427-30, 1993 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-7692599

RESUMEN

Electrophysiology and structural studies were performed on an annexin V variant containing a mutation of glutamic acid-95 to serine in the center of the pore region. The mutation resulted in a lower single channel conductance for calcium and a strongly increased conductance for sodium and potassium, indicating that glutamic acid-95 is a crucial constituent of the ion selectivity filter. There were only minor differences in the crystal structures of mutant and wild-type annexin V around the mutation site; however, the mutant showed structural differences elsewhere, including the presence of a calcium binding site in domain III unrelated to the mutation. Analysis of the membrane-bound form of annexin V by electron microscopy revealed no differences between the wild type and mutant.


Asunto(s)
Anexina A5/química , Canales Iónicos/metabolismo , Anexina A5/genética , Anexina A5/metabolismo , Sitios de Unión , Calcio/metabolismo , Gráficos por Computador , Cristalografía por Rayos X , Conductividad Eléctrica , Glutamatos/química , Ácido Glutámico , Humanos , Microscopía Electrónica , Mutagénesis Sitio-Dirigida , Potasio/metabolismo , Estructura Secundaria de Proteína , Serina/química , Sodio/metabolismo , Relación Estructura-Actividad
5.
Trends Biochem Sci ; 19(7): 272-6, 1994 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-7519374

RESUMEN

Annexin V is a Ca(2+)-dependent membrane-binding protein that forms voltage-dependent Ca2+ channels in phospholipid bilayers and is the first ion channel to be structurally and functionally characterized. Data outlined here indicate that key amino acid residues act as selectivity filters and voltage sensors, thereby regulating the permeability of the channel pore to ions.


Asunto(s)
Anexina A5/fisiología , Canales Iónicos/fisiología , Anexina A5/química , Canales de Calcio/química , Canales de Calcio/fisiología , Membrana Celular/fisiología , Análisis Mutacional de ADN , Humanos , Activación del Canal Iónico , Mutación , Conformación Proteica , Relación Estructura-Actividad
6.
Pediatr Rheumatol Online J ; 16(1): 22, 2018 Apr 05.
Artículo en Inglés | MEDLINE | ID: mdl-29622022

RESUMEN

BACKGROUND: Systemic juvenile idiopathic arthritis (sJIA) is a complex disease with an autoinflammatory component of unknown etiology related to the innate immune system. A major role in the pathogenesis has been ascribed to proinflammatory cytokines like interleukin-6 (IL-6), and effective drugs inhibiting their signaling are being developed. This study evaluates sJIA patients treated with the IL-6 inhibitor tocilizumab (TCZ) concerning clinical response rate, disease course and adverse effects in a real-life clinical setting. METHODS: In 2009 a clinical and research consortium was established, including an online registry for autoinflammatory diseases (AID) ( https://aid-register.de ). Data for this retrospective TCZ study were documented by 13 centers. RESULTS: From 7/2009 to 4/2014, 200 patients with sJIA were recorded in the AID-registry. Out of these, 46 (19 m, 27 f, age 1-18 years) received therapy with TCZ. Long term treatment (median 23 months) has been documented in 24/46 patients who were evaluated according to Wallace criteria (active disease 6/24, inactive disease 5/24, remission 13/24 cases). Under observation co-medication were used in 40/46 cases. Adverse events were reported in 11/46 patients. The clinical response rate (no clinical manifestation, no increased inflammation parameters) within the first 12 weeks of treatment was calculated to be 35%. CONCLUSION: Out of 200 sJIA children reported in the German AID-registry, 46 were treated with TCZ, showing a clinical response rate of 35% during the first 12 weeks, and inactive disease and/or remission under medication in 75% after one year. Adverse events were seen in 24% and severe adverse events in 4%. TRIAL REGISTRATION: The AID-Registry is funded by the BMBF (01GM08104, 01GM1112D, 01GM1512D).


Asunto(s)
Anticuerpos Monoclonales Humanizados/uso terapéutico , Artritis Juvenil/tratamiento farmacológico , Interleucina-6/antagonistas & inhibidores , Adolescente , Anticuerpos Monoclonales Humanizados/efectos adversos , Niño , Preescolar , Femenino , Alemania , Humanos , Masculino , Sistema de Registros , Inducción de Remisión , Estudios Retrospectivos , Resultado del Tratamiento , Adulto Joven
7.
J Mol Biol ; 223(3): 683-704, 1992 Feb 05.
Artículo en Inglés | MEDLINE | ID: mdl-1311770

RESUMEN

Two crystal forms (P6(3) and R3) of human annexin V have been crystallographically refined at 2.3 A and 2.0 A resolution to R-values of 0.184 and 0.174, respectively, applying very tight stereochemical restraints with deviations from ideal geometry of 0.01 A and 2 degrees. The three independent molecules (2 in P6(3), 1 in R3) are similar, with deviations in C alpha positions of 0.6 A. The polypeptide chain of 320 amino acid residues is folded into a planar cyclic arrangement of four repeats. The repeats have similar structures of five alpha-helical segments wound into a right-handed compact superhelix. Three calcium ion sites in repeats I, II and IV and two lanthanum ion sites in repeat I have been found in the R3 crystals. They are located at the convex face of the molecule opposite the N terminus. Repeat III has a different conformation at this site and no calcium bound. The calcium sites are similar to the phospholipase A2 calcium-binding site, suggesting analogy also in phospholipid interaction. The center of the molecule is formed by a channel of polar charged residues, which also harbors a chain of ordered water molecules conserved in the different crystal forms. Comparison with amino acid sequences of other annexins shows a high degree of similarity between them. Long insertions are found only at the N termini. Most conserved are the residues forming the metal-binding sites and the polar channel. Annexins V and VII form voltage-gated calcium ion channels when bound to membranes in vitro. We suggest that annexins bind with their convex face to membranes, causing local disorder and permeability of the phospholipid bilayers. Annexins are Janus-faced proteins that face phospholipid and water and mediate calcium transport.


Asunto(s)
Proteínas de Unión al Calcio/química , Proteínas de la Membrana/química , Proteínas Gestacionales/química , Secuencia de Aminoácidos , Anexina A5 , Calcio/metabolismo , Canales de Calcio/química , Canales de Calcio/metabolismo , Proteínas de Unión al Calcio/metabolismo , Membrana Celular/metabolismo , Conductividad Eléctrica , Humanos , Enlace de Hidrógeno , Activación del Canal Iónico , Proteínas de la Membrana/metabolismo , Modelos Moleculares , Datos de Secuencia Molecular , Fosforilación , Proteínas Gestacionales/metabolismo , Conformación Proteica , Secuencias Repetitivas de Ácidos Nucleicos , Alineación de Secuencia , Solventes , Difracción de Rayos X
8.
J Mol Biol ; 238(2): 199-213, 1994 Apr 29.
Artículo en Inglés | MEDLINE | ID: mdl-8158649

RESUMEN

We have used electron microscopy to analyse the structure of wild-type human annexin V (recombinant and placental) and of several mutants (single and double point mutants) bound to monolayers composed of DOPS, DOPE, or brain extract (Folch fraction III). On these phospholipids and on DOPS/DOPC (3:1, w/w) protein trimers, as also found in 3-D crystals, assemble to form a hexagonal lattice with a unit vector length of about 18 nm. The resolution obtained in projection is 1.7 to 2.2 nm for wild-type and mutants. There are no significant differences between the annexin V mutants and the wild-type protein at this resolution. All proteins bind as trimers with their convex side harbouring the Ca(2+)-binding sites facing the membrane. A comparison of the 3-D reconstruction of annexin V wild-type with the high resolution crystal structure shows that the domain structure is preserved but the relative orientation of the modules (II/III) and (I/IV) is slightly changed so that the Ca(2+)-binding sites in all four domains (including the recently observed binding site in domain III) become coplanar to the membrane. The thickness of the molecule obtained in the 3-D reconstruction corresponds well with the thickness of the high resolution crystal structure indicative of peripheral binding of annexin V without substantial penetration of the membrane.


Asunto(s)
Anexina A5/química , Proteínas de la Membrana/química , Biopolímeros , Cristalización , Cristalografía por Rayos X , Microscopía Electrónica , Modelos Moleculares , Conformación Proteica
9.
J Mol Biol ; 237(4): 479-99, 1994 Apr 08.
Artículo en Inglés | MEDLINE | ID: mdl-8151707

RESUMEN

Annexin V binds to phospholipids in a calcium-dependent manner and exhibits calcium channel activity in vitro. We prepared a variety of mutants yielding information about the structure-function relationship of the ion channel activity. All mutants were characterized by X-ray crystallography, electron microscopy and electrophysiological measurements. Their structures are insignificantly changed whereas their electrophysiological properties are drastically different. Glu95, located in the central hydrophilic pore of the molecule, is crucial for the ion selectivity filter as its exchange leads to reduced calcium and increased sodium conductance. The removal of Glu17, located on the protein surface and far from the ion conduction pathway, leads to the appearance of a second conductance level of 9 pS in addition to the conductance level of about 30 pS in the wild-type molecule. This was also the case for Glu78, which is part of a weak calcium binding site. The exchange of Glu17 and Glu78 produced a mutant retaining only the smaller conductance level. We conclude that these two residues influence the angle between the two halves of the molecule, which determines the diameter of the ion conduction pathway, thereby leading to the occurrence of a second conductance level.


Asunto(s)
Anexina A5/química , Anexina A5/fisiología , Canales de Calcio/química , Canales de Calcio/fisiología , Mutagénesis Sitio-Dirigida , Estructura Secundaria de Proteína , Secuencia de Aminoácidos , Anexina A5/ultraestructura , Secuencia de Bases , Calcio/metabolismo , Canales de Calcio/biosíntesis , Clonación Molecular , Cristalografía por Rayos X/métodos , Electrofisiología/métodos , Humanos , Membrana Dobles de Lípidos , Potenciales de la Membrana , Microscopía Electrónica , Modelos Moleculares , Modelos Estructurales , Datos de Secuencia Molecular , Oligodesoxirribonucleótidos , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Proteínas Recombinantes/ultraestructura , Mapeo Restrictivo , Sodio/metabolismo
10.
J Mol Biol ; 257(4): 839-47, 1996 Apr 12.
Artículo en Inglés | MEDLINE | ID: mdl-8636985

RESUMEN

Annexin II binds in a calcium-dependent manner to acidic phospholipids and is a substrate of some protein kinases. An N-terminally shortened form of human annexin II was crystallized and its molecular structure determined. It is very similar to two previously described members of this protein family, annexin I and annexin V. The protein structure is nearly completely alpha-helical organized as four compact domains which consist of five alpha-helices each. The domains surround a hydrophilic pore. The calcium binding sites are located at the convex side of the structure as in annexin V. Recombinant and natural porcine annexin II are active as ion channel with characteristics similar to annexin V, while N-terminally shortened annexin II and the heterotetramer (annexin II-p11)2 are inactive. Two cysteine residues, Cys133 and Cys262, form a disulphide bridge connecting domains II and III, adding further weight to the notion that ion channel activity does not require major structural rearrangements.


Asunto(s)
Anexina A2/química , Canales Iónicos/química , Proteínas de la Membrana/química , Secuencia de Aminoácidos , Animales , Anexina A2/genética , Anexina A2/metabolismo , Sitios de Unión , Calcio/metabolismo , Cristalografía por Rayos X , Disulfuros/química , Conductividad Eléctrica , Humanos , Canales Iónicos/genética , Canales Iónicos/metabolismo , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Modelos Moleculares , Datos de Secuencia Molecular , Fragmentos de Péptidos/química , Fragmentos de Péptidos/metabolismo , Conformación Proteica , Proteínas Recombinantes/metabolismo , Homología de Secuencia de Aminoácido , Porcinos
11.
FEBS Lett ; 329(1-2): 25-8, 1993 Aug 23.
Artículo en Inglés | MEDLINE | ID: mdl-8354401

RESUMEN

Annexin V binds in a calcium-dependent manner to acidic phospholipids and exhibits ion channel activity in vitro. We are investigating mutants of annexin V by single channel measurements, X-ray crystallography and electron microscopy in order to understand the structure-function relationships of the ion channel activity. We describe here a method to obtain very pure recombinant annexin V required for such studies. The initial step is the mild opening of the bacterial cells by an osmotic shock. In the purification procedure, use is made of the reversible calcium-mediated binding of annexin V to liposomes. In the last purification step the protein is subjected to ion-exchange chromatography and elutes as a single peak free of any detectable contaminants.


Asunto(s)
Anexina A5/aislamiento & purificación , Animales , Calcio/farmacología , Bovinos , Pared Celular/química , Cristalización , Electroforesis en Gel de Poliacrilamida , Escherichia coli/química , Liposomas/metabolismo , Presión Osmótica , Proteínas Recombinantes/aislamiento & purificación , Difracción de Rayos X
12.
FEBS Lett ; 317(1-2): 131-4, 1993 Feb 08.
Artículo en Inglés | MEDLINE | ID: mdl-7679080

RESUMEN

A new assay for the calcium channel activity of annexin V was developed. The calcium-sensitive fluorescence indicator, fura-2, was incorporated into large unilamellar vesicles (LUV). After establishing a calcium gradient across the liposomal membranes, native or mutated annexin V was added. The resulting calcium influx into the LUV detected through the fluorescence changes of fura-2 was used as a qualitative test for the electrophysiological properties of annexin V.


Asunto(s)
Anexina A5/metabolismo , Calcio/metabolismo , Fura-2 , Canales Iónicos/metabolismo , Transporte Biológico , Liposomas
13.
Biol Chem Hoppe Seyler ; 373(1): 35-42, 1992 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-1536691

RESUMEN

1) The biological cofactor and carrier activities of dolichyl phosphates of low isoprene multiplicity (n) and defined geometry, (synthesized according to L. Jaenicke and H.-U. Siegmund, Chem. Phys. Lipids 51 (1989) 159-170), were assayed in different transfer reactions of the microsomal dolichyl-phosphate cycle against natural pig liver dolichyl phosphate (n = 18 to 20). 2) The apparent Michaelis constants and maximal velocities were determined from initial reaction rates for the transfer from GDP-mannose, UDP-N-acetylglucosamine, and UDP-glucose to the synthetic truncated dolichyl phosphates. They afford quantitative comparison and show increasing biological activities from dolichyl-6 phosphate to dolichyl-11 phosphate, which is about as active as the natural mixture. This is in accord with previous findings on the starting reactions of the cycle. 3) Truncated dolichyl diphosphochitobioses, biosynthesized in vitro from synthetic dolichyl phosphates, were used as acceptors for nucleoside diphosphohexoses in solubilized membranes. All of them show about the same activity. The kinetics and yield were determined for each of the transfers. Activity is increased by adding UDP-glucose. The inactive very short-chain dolichol compounds do not interfere with the transfer to active longer chain dolichols. 4) The oligosaccharides produced by transfer of mannose and glucose to truncated dolichyl diphosphate-bound chitobiose were isolated and analysed for sugar multiplicity. The heptasaccharide and the un-decasaccharide are accumulated most, pointing to the transport across the endoplasmic membranes (ER) as the rate limiting reaction. 5) The truncated dolichyl-diphosphate-bound oligosaccharides are transferred to protein(s) by the crude, solubilized microsomal preparation independent of chain length of the cofactor/carrier, yet with increasing yield as shown by enzyme immunoblot analysis.


Asunto(s)
Fosfatos de Dolicol/metabolismo , Microsomas Hepáticos/metabolismo , Animales , Bovinos , Fosfatos de Dolicol/química , Glicosilación , Hexosas/metabolismo , Técnicas In Vitro , Especificidad por Sustrato
14.
Geburtshilfe Frauenheilkd ; 38(4): 260-9, 1978 Apr.
Artículo en Alemán | MEDLINE | ID: mdl-648850

RESUMEN

By means of ultrasound and fetal electrocardiography the diagnosis of twin pregnancies can be made prenatally without any reservation; the diagnosis is even possible in the first half of pregnancy. Comparative analysis of two approximately equal collectives of in all 602 twin pregnancies--1,45% of all births in the years 1955-1975 at the University Clinic for Gynecology and Obstetrics of the University of Cologne--revealed a better prognosis concerning the course of pregnancy and the new-born by prenatal diagnosis. The earliest possible diagnosis of twins, resulting in more intense clinical observation--and occasional clinical treatment--facilitated a significantly longer duration of pregnancy, leading to a higher percentage of mature twins. Whereas the total number of obstetric operations was reduced because of prenatal diagnosis, selection of highrisk cases led to a distinct increase in Caesarian sections. The prolongation of pregnancy, the higher birth weights and better maturity attained, were accompanied by decrease in perinatal mortality and in improvement in the Apgar-index of the newborn in that collective, in which prenatal diagnosis was achieved.


Asunto(s)
Embarazo Múltiple , Diagnóstico Prenatal , Gemelos , Puntaje de Apgar , Peso al Nacer , Cesárea , Electrocardiografía , Femenino , Corazón Fetal , Alemania Occidental , Humanos , Mortalidad Infantil , Embarazo , Factores de Tiempo , Ultrasonografía
15.
Fortschr Med ; 96(7): 351-6, 1978 Feb 16.
Artículo en Alemán | MEDLINE | ID: mdl-627383

RESUMEN

The analysis of 751 postcoital tests performed in patients consulting the infertility clinic of the Department of Obstetrics and Gynecology, University of Cologne, allows the following diagnostic and prognostic conclusions: 1. In case motile spermatozoa are present in the cervical mucus, the assumption can be made that adaequate insemination takes place. 2. The postcoital test and the simultaneous examination of the cervix factors offer themselves for the assessment of the estrogenic status during the normal cycle or after stimulation with clomiphene, HMG-HCG or estrogen. 3. The timing of the postcoital test itself results in a remarkable increase in pregnancy rates. 4. The pregnancy rates are higher when higher numbers of motile sperms are found in the cervical mucus. 5. Negative or doubtful postcoital tests do not rule out the possibility of pregnancy. 6. The postcoital test provides some information about the number of spermatozoa, their progressive motility, their morphology and about the interaction of spermatozoa with the cervical mucus. However, the postcoital test cannot replace a complete semen analysis.


Asunto(s)
Moco del Cuello Uterino/citología , Infertilidad/terapia , Espermatozoides/citología , Coito , Femenino , Humanos , Masculino , Embarazo , Motilidad Espermática
16.
Behring Inst Mitt ; (91): 107-25, 1992 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-1388018

RESUMEN

Annexins constitute a family of cytosolic, water soluble proteins, which bind to negatively charged phospholipids in a calcium-dependent manner. They display structural and functional features of both soluble and integral membrane proteins. The annexins face the hydrophilic as well as the hydrophobic phase (Janus-faced proteins) and mediate ion transport in vitro. We present the refined structure and molecular model of annexin V at 2.0 A resolution. The molecule is almost entirely alpha-helical, and each of the four repeats of annexin V is folded into a compact domain of similar structure. The four domains are arranged in an almost planar, cyclic array. In the center of the molecule, one can find a prominent hydrophilic pore, which we associate with the calcium-selective channel found in annexin V. Annexin V has an overall flat, slightly curved shape with two faces, one convex and one concave. The three calcium binding sites Ca1 to Ca3, all located at the convex face of the molecule, are assumed to be phospholipid binding sites, as suggested by their structural similarity to the calcium site of phospholipase A2. Soluble and membrane-bound annexin have closely similar structures, as shown by electron microscopic analysis. Several other observations provide evidence that the membrane-anchoring region of the annexin V molecule is located on the convex face. In the last part of this article, the electrophysiology of the annexins is described. Ion permeation occurs in discrete conductance states and is regulated by voltage across the membrane. A model for the annexin V-membrane interaction, the ion channel formation, and the ion conduction pathway is proposed.


Asunto(s)
Proteínas de Unión al Calcio/química , Proteínas de Unión al Calcio/fisiología , Proteínas Gestacionales/química , Proteínas Gestacionales/fisiología , Secuencia de Aminoácidos , Animales , Anexina A5 , Sitios de Unión , Calcio/metabolismo , Electrofisiología , Humanos , Modelos Moleculares , Fosforilación , Conformación Proteica
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA