'Why have women not returned to use their frozen oocytes?': a 5-year follow-up of women after planned oocyte cryopreservation.

RESEARCH QUESTION: What are the reproductive choices and retrospective reflections of women at least 4 years after planned oocyte cryopreservation (POC)? DESIGN: This was an internet survey, using the REDCap application, of women who underwent POC, at a single-centre university-affiliated IVF unit, 4-8 years before the survey. The questionnaire addressed reproductive choices and outcomes following POC. RESULTS: Seventy-nine women who underwent POC during 2011-2014 were invited to participate, and 70 (89%) responded. Mean age at cryopreservation was 37.1 ± 2.4 (range 30-41) years, mean age at study participation 42.6 ± 2.6 (range 35-48) years, and mean time from first cryopreservation cycle to study participation 5.5 ± 1.3 (range 4-8) years. The main retrospectively reported reason for POC was not wanting to become pregnant without a partner (59, 84%). During the follow-up period, 44 women (63%) attempted to conceive either naturally or by assisted reproductive technology using fresh or cryopreserved oocytes. Of those, 28 women achieved a live birth (64% of those who tried to conceive). Fourteen respondents (20% of all respondents) reported using their cryopreserved oocytes, and three (21%) achieved a birth using those oocytes. Fifteen women (34%) of those who tried to conceive used donor spermatozoa. CONCLUSIONS: The most common reasons for not using frozen oocytes were achieving pregnancy without frozen oocytes or preferring not to have a child without a partner. A considerable proportion of women who had POC and were not interested in being a single parent by choice eventually try to conceive using donor spermatozoa several years later.

Split invertase polypeptides form functional complexes in the yeast periplasm in vivo.

The assembly of functional proteins from fragments in vivo has been recently described for several proteins, including the secreted maltose binding protein in Escherichia coli. Here we demonstrate for the first time that split gene products can function within the eukaryotic secretory system. Saccharomyces cerevisiae strains able to use sucrose produce the enzyme invertase, which is targeted by a signal peptide to the central secretory pathway and the periplasmic space. Using this enzyme as a model we find the following: (i) Polypeptide fragments of invertase, each containing a signal peptide, are independently translocated into the endoplasmic reticulum (ER) are modified by glycosylation, and travel the entire secretory pathway reaching the yeast periplasm. (ii) Simultaneous expression of independently translated and translocated overlapping fragments of invertase leads to the formation of an enzymatically active complex, whereas individually expressed fragments exhibit no activity. (iii) An active invertase complex is assembled in the ER, is targeted to the yeast periplasm, and is biologically functional, as judged by its ability to facilitate growth on sucrose as a single carbon source. These observation are discussed in relation to protein folding and assembly in the ER and to the trafficking of proteins through the secretory pathway.

Human autoantibody to defensin: disease association with hyperreactive onchocerciasis (sowda).

Chronic hyperreactive onchodermatitis (sowda) is a severe form of onchocerciasis observed in a subset of individuals infected with the filarial nematode Onchocerca volvulus. SDS-PAGE and immunoblot analyses of O. volvulus adult worm extracts were used to characterize the antigens of the marked antibody response of sowda patients. One 2.5-kD antigen was recognized by sera from all 35(100%) sowda patients that were studied. In comparison, only 7 of 44 (16%) patients with generalized onchocerciasis and 11 of 21 (52%) of exposed individuals with no microfilariae in skin snips and no signs of disease showed reactivity to this antigen. Microfilaricidal treatment of sowda patients with improvement of the clinical status was associated with a decrease or disappearance of antibodies to the 2.5-kD antigen. Amino acid sequencing of the antigen indicated identity to human defensins 1-3 of neutrophils. Defensin was demonstrated by immunohistochemical staining in onchocercal nodules on the surface of adult filariae and in the surrounding tissue. A similar staining pattern was observed for other proteins present in neutrophils such as myeloperoxidase, elastase, and the L-1 protein complex (MRP 8/MRP 14), indicating that neutrophils, macrophages, and their proteins predominate in the environment adjacent to the worms. These results demonstrate an association between the presence of autoantibodies to defensins and an infectious disease of known etiology. The association with a particular form of onchocerciasis, sowda, suggests a link between formation of autoantibodies to defensin and enhanced immune reactivity towards the parasite.

Targeting and assembly of an oligomeric bacterial enterotoxoid in the endoplasmic reticulum of Saccharomyces cerevisiae.

A hybrid protein consisting of the Escherichia coli lipoprotein signal sequence attached to the mature sequence of the B subunit of heat-labile enterotoxin (Lipo-EtxB) was expressed in yeast and E. coli. Analyses of cell lysates from Saccharomyces cerevisiae and E. coli expressing the protein revealed that both organisms were able to assemble Lipo-EtxB into oligomers that were (i) stable in the presence of sodium dodecyl sulphate, (ii) resistant to proteinase K degradation, and (iii) able to bind to GM1-ganglioside receptors. Each of these properties are characteristic of the wild-type B subunit pentamer produced in E. coli. Assembly of Lipo-EtxB was found to be unaffected in a sec18 mutant of S. cerevisiae, which possesses a temperature-sensitive defect in protein transport from the endoplasmic reticulum (ER) to the Golgi apparatus, but was found not to assemble in a sec53 mutant, which causes the misfolding of proteins targeted to the ER. A kar2-1 mutation with a defect in the yeast homologue of BiP caused an 18-fold reduction in Lipo-EtxB assembly at the non-permissive temperature in S. cerevisiae. However, introduction of the wild-type KAR2 gene on a plasmid into the kar2-1 mutant completely suppressed the inhibition of Lipo-EtxB assembly. This provides the first evidence that KAR2 facilitates the assembly of an oligomeric protein in yeast and thus implicates KAR2 as a 'molecular chaperone'. The possible mechanisms of enterotoxoid assembly in E. coli and S. cerevisiae are discussed.

Isolation of acid-resistant urinary trypsin inhibitors by high performance liquid chromatography and their characterization by N-terminal amino-acid sequence determination.

Two crude fractions of acid-resistant trypsin inhibitors (apparent molecular masses 44 and 20 kDa, respectively) were prepared from human urine by gel permeation chromatography. From both preparations the pure inhibitors were isolated by high performance liquid chromatography (HPLC). Their N-terminal amino-acid sequences were determined and compared with those of HI-30 and HI-14 as isolated by reversible binding to either immobilized trypsin or immobilized chymotrypsin. The N-terminal amino-acid sequence of the high-molecular mass inhibitor UI-I isolated by HPLC was identical with those of HI-30 and UI-C-I isolated via immobilized trypsin or chymotrypsin, respectively. The low-molecular mass inhibitors UI-II and UI-C-II differ from HI-14 by the N-terminal extension Glu-Val-Thr-Lys-when obtained by HPLC or by the extension Thr-Lys-when obtained via immobilized chymotrypsin, respectively. The comparison of these N-termini with the amino-acid sequence of HI-30 (Ala1-...-Val16-Thr-Glu-Val-Thr-Lys-HI-14) defines the low molecular urinary trypsin inhibitors as proteolytic degradation products of the high-molecular urinary inhibitor. Proteolysis may occur at different bonds. The existing discrepancies in molecular architecture and in molecular masses of the urinary trypsin inhibitors are discussed.

Kunitz-type proteinase inhibitors derived by limited proteolysis of the inter-alpha-trypsin inhibitor, VII. Characterization of the bovine inhibitor as double-headed trypsin-elastase inhibitor.

The acid-resistant 14-kDa inhibitor BI-14, released from bovine inter-alpha-trypsin inhibitor, consists of two tandem Kunitz-type domains, and is of a double-headed nature. The Arg-Thr bond connecting both domains was cleaved and the two inhibitory domains were separated. The N-terminal domain is an inhibitor of bovine chymotrypsin and elastases from porcine pancreases and human polymorphonuclear granulocytes, whereas the C-terminal domain interacts with trypsin, plasmin, and chymotrypsin. In the intact inhibitor BI-14 both domains interact independently with the proteinases.

Kunitz-type proteinase inhibitors derived by limited proteolysis of the inter-alpha-trypsin inhibitor, IX. Isolation and characterization of the inhibitory parts of inter-alpha-trypsin inhibitors from several mammalian sera.

The inhibitory parts of inter-alpha-trypsin inhibitor-like proteins from several mammalian sera (sheep, goat, horse, donkey, pig, rabbit, rat and dog) were released by limited proteolysis with trypsin and were isolated by reversible binding to immobilized trypsin. The inhibitors are very similar with respect to their stability in acids, molecular masses and amino-acid compositions. They are different, however, in their inhibitory properties. In view of the known covalent structures of the inhibitory parts of the human and bovine inhibitors, homologous covalent structures consisting of two tandem Kunitz-type domains are suggested also for the isolated inhibitors. Bovine trypsin, bovine chymotrypsin and porcine plasmin are inhibited by all investigated inhibitors, most likely via their C-terminal domain. The inhibitors from horse, donkey, rabbit, rat and dog serum interact also with elastase from human polymorphonuclear granulocytes, those from sheep, goat and pig serum inhibit in addition porcine pancreatic elastase and bovine chymotrypsin via their N-terminal Kunitz-type domain. It is supposed that the amino-acid residue in position P1 of the N-terminal Kunitz-type domain is responsible for the characteristic inhibitory properties of each inhibitor.

Isolation and characterization of an inter-alpha-trypsin inhibitor-IgG complex from human serum.

Inter-alpha-trypsin inhibitor is a human serum protease inhibitor of Mr 180 000 which may release physiological derivatives. A complex between IgG and an inter-alpha-trypsin inhibitor derivative of Mr 30 000 has been recently detected in human serum and was found to be inactive against trypsin, in contrast with the known inhibitory activity of the free 30-kDa derivative. The present study deals with detailed characterization of an inter-alpha-trypsin inhibitor-IgG complex following its purification by affinity chromatography techniques (anti-inter-alpha-trypsin inhibitor immunoadsorbent and Protein A-Sepharose) in mild conditions. The resulting product reacted simultaneously with anti-IgG and anti-inter-alpha-trypsin inhibitor antibodies. This complex contained Mr 180 000 inhibitor at least to some extent. It migrated in the beta-gamma zone in agarose; its molecular weight was estimated to be 1 500 000 or more; part of it displayed covalent bonding between inter-alpha-trypsin inhibitor and IgG; it had a trypsin inhibitor activity. Immunoelectrophoresis allowed one to demonstrate the native complex in serum owing to the use of anti-inter-alpha-trypsin inhibitor and anti-gamma radioactively labelled antibodies. The double immunoreactivity thus evidenced proved to be heterogeneous with respect to its level and location in the native as well as in the purified complex.

Kunitz-type proteinase inhibitors derived by limited proteolysis of the inter-alpha-trypsin inhibitor, V. Attachments of carbohydrates in the human urinary trypsin inhibitor isolated by affinity chromatography.

The inhibitory active part of the inter-alpha-trypsin inhibitor with a known amino acid sequence is present as an acid-resistant inhibitor in human serum, in urine, in bronchial and in nasal mucus. The inhibitor molecule has a 50% carbohydrate content. Carbohydrate side chains are attached in two positions. One chain is linked to the polypeptide O-glycosidically via the serine residue in position 10 in the N-terminal extension peptide. The second side chain is attached N-glycosidically via the asparagine residue in position 24, located in the inactive "inhibitory" Kunitz-type domain of the inhibitor. The composition of the carbohydrate side chains were determined.

Kunitz-type proteinase inhibitors derived by limited proteolysis of the inter-alpha-trypsin inhibitor. VI. Detection of a complex between immunoglobulin g and the inhibitory active part of the inter-alpha-trypsin inhibitor.

A latent trypsin inhibitor is released from denatured human serum proteins by proteolytic digestion with thermolysin. The latent inhibitor was enriched by chromatography on DEAE-Sephacel, Sephadex G-200, and Protein A-Sepharose, respectively. Immunological cross-section identified the latent inhibitor as a complex between IgG and the inhibitory active part of the inter-alpha-trypsin inhibitor.

An elastase-specific inhibitor from human bronchial mucus. Isolation and characterization.

It was shown previously that human bronchial mucus contains an acid-stable proteinase inhibitor directed against trypsin and chymotrypsin, polymorphonuclear granulocyte elastase and cathepsin G. In addition to this well-characterized inhibitor, designated here as BSI-ATE (identical with the inhibitor HUSI-I from human seminal plasma or antileucoprotease), another acid-stable inhibitor BSI-E is present in the mucus which exerts inhibitory activity towards porcine pancreatic and human granulocytic elastase, but not against trypsin, chymotrypsin, or granulocytic cathepsin G. This elastase-specific inhibitor was isolated by affinity chromatography. Its molecular mass and its amino acid composition are very similar to those of BSI-TE. An immunological cross-reactivity between both inhibitor species was not observed. In the mucus of patients suffering from obstructive airway disease the elastase-specific inhibitor is not present in the free form but can be liberated by acidification.

N-Acetylalanine aminopeptidase, a new enzyme from human erythrocytes.

A new enzyme liberating N-acetylalanine from N-acetylalanine peptides with high specificity has been isolated from the cytosol of human erythrocytes. The N-acetylalanine aminopeptidase was purified by ammonium sulfate precipitation at 60% saturation, followed by chromatography on columns of Sephadex G-200, SP-Sephadex C-50, and DEAE-Sephadex A-50. About 2 000-fold enrichment was achieved from hemolyzed erythrocytes. The enzyme was homogeneous according to polyacrylamide disc electrophoresis and had a specific activity of 18.1 U/A280 unit. An apparent molecular weight of 300 000 +/- 15 000 was obtained from gel filtrations and was confirmed in the ultracentrifuge in "an active enzyme centrifugation" giving a corrected sedimentation value, s20w of 12 S. The pH optimum in triethanolamine/HCl buffer was around pH 8.3 with N-acetylalanine-4-nitroanilide as substrate, the Km was 0.616 mmol/l. The enzyme was stable between pH 6.0 to 8.0, but lost enzymic activity rapidly below pH 5 and with organic solvents. It is stabilized in a 0.1 M solution of ammonium sulfate. The activity was destroyed by high concentrations of chloromercuribenzoate and di(2-pyridyl)disulfide in an unspecific manner and could not be restored by cysteine. Various protein endoproteinase inhibitors are without influence on the enzymic activity. The enzyme exhibits an aminopeptidase-like activity with release of N-acetylalanine in order of decreasing activity from N-acetylalanine-4-nitroanilide, N-acetylalanyl-alanylalanine, N-acetylalanyl-tyrosyl-isoleucine, N-acetylalanylalanine, N-acetylalanyl-alanyl-alanylalanine, and N-acetylalanine ethyl ester. Several unacetylated peptides and alanine-4-nitroanilide as well as protein substrates were not hydrolyzed. The enzymic activity has not been found in the cytosolic compartment of highly purified human leucocytes. Its physiological function in erythrocytes is still unknown.

[Studies for proteolysis in malignant tumours (author's transl)]. / Untersuchungen zur Proteolyse bei malignen Tumoren.

It's well known that increased proteolytic activity in plasma as well as in interstitial fluids is often associated with malignant tumours. There are numerous reports that cell cultures of malignant origin contain plasminogen activators responsible for an increased proteolysis. Our studies showed that patients with a carcinoma excrete in their urine a significant higher amount of an acid-stable inhibitor than healthy patients. This urine inhibitor is a split product (MW: 30,000) of the Inter-alpha-trypsin inhibitor (MW: 180,000). We conclude that the increased amount of acid-stable split products is the result of increased proteolysis in patients with malignant tumours. In contrast to other authors we do not think that the activation of plasmin by plasminogen is responsible for the proteolytic cleavage of ITI. Otherwise proteolysis by Cathepsin G and granulocytic Elastase would be reasonable. So enhanced proteolysis seems to be a sign of general enzymatic change associated with transformation.