Outcome of fetal ovarian cysts diagnosed on prenatal ultrasound examination: systematic review and meta-analysis.

OBJECTIVE: To explore the outcome of fetuses with a prenatal diagnosis of ovarian cyst. METHODS: The electronic databases MEDLINE and EMBASE were searched using keywords and word variants for 'ovarian cysts', 'ultrasound' and 'outcome'. The following outcomes in fetuses with a prenatal diagnosis of ovarian cyst were explored: resolution of the cyst, change of ultrasound pattern of the cyst, occurrence of ovarian torsion and intracystic hemorrhage, need for postnatal surgery, need for oophorectomy, accuracy of prenatal ultrasound examination in correctly identifying ovarian cyst, type of ovarian cyst at histopathological analysis and intrauterine treatment. Meta-analyses using individual data random-effects logistic regression and meta-analyses of proportions were performed. Quality assessment of the included studies was performed using the Newcastle-Ottawa Scale. RESULTS: Thirty-four studies (954 fetuses) were included. In 53.8% (95% CI, 46.0-61.5%) of cases for which resolution of the cyst was evaluated (784 fetuses), the cyst regressed either during pregnancy or after birth. The likelihood of resolution was significantly lower in complex vs simple cysts (odds ratio (OR), 0.15 (95% CI, 0.10-0.23)) and in cysts measuring ≥ 40 mm vs < 40 mm (OR, 0.03 (95% CI, 0.01-0.06)). Change in ultrasound pattern of the cyst was associated with an increased risk of ovarian loss (surgical removal or autoamputation) (pooled proportion, 57.7% (95% CI, 42.9-71.8%)). The risk of ovarian torsion was significantly higher for cysts measuring ≥ 40 mm compared with < 40 mm (OR, 30.8 (95% CI, 8.6-110.0)). The likelihood of having postnatal surgery was higher in patients with cysts ≥ 40 mm compared with < 40 mm (OR, 64.4 (95% CI, 23.6-175.0)) and in complex compared with simple cysts, irrespective of cyst size (OR, 14.6 (95% CI, 8.5-24.8)). In cases undergoing prenatal aspiration of the cyst, rate of recurrence was 37.9% (95% CI, 14.8-64.3%), ovarian torsion and intracystic hemorrhage were diagnosed after birth in 10.8% (95% CI, 4.4-19.7%) and 12.8% (95% CI, 3.8-26.0%), respectively, and 21.8% (95% CI, 0.9-40.0%) had surgery after birth. CONCLUSION: Size and ultrasound appearance are the major determinants of perinatal outcome in fetuses with ovarian cysts. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Outcomes associated with fetal hepatobiliary cysts: systematic review and meta-analysis.

OBJECTIVE: To explore the outcomes associated with fetal hepatobiliary cysts. METHODS: MEDLINE and EMBASE were searched for studies reporting on outcomes of fetal hepatobiliary cysts. Outcomes observed were resolution/reduction and increase in cyst size, associated congenital anomalies of the biliary tract and liver, abnormal postnatal liver function tests, clinical symptoms, need for surgery, postsurgical complications and predictive accuracy of prenatal ultrasound in identifying correctly hepatobiliary cysts. Meta-analysis of proportions was used to analyze the data. RESULTS: The search identified 1498 articles, and 22 studies (252 fetuses) were included in the systematic review. For fetal hepatic cysts, resolution or reduction in cyst size either pre- or postnatally occurred in 59.3% (95% CI, 30.9-84.7%) of cases, while an increase in cyst size occurred in 8.7% (95% CI, 1.1-22.4%). No case of hepatic cyst had associated malformations of the biliary tract at birth. Clinical symptoms occurred in 14.8% (95% CI, 6.3-26.1%) of cases and, in 5.4% (95% CI, 0.9-13.6%), they were related to the presence of bile obstruction due to compression of the cyst on the biliary tract. No case of hepatic cyst had abnormal liver function at birth. For fetal biliary cysts, resolution or reduction in cyst size occurred in 8.7% (95% CI, 2.7-17.5%) of cases and an increase in size occurred in 34.4% (95% CI, 20.5-49.8%). Congenital anomalies of the biliary tract and liver, such as fibrosis, occurred in 21.5% (95% CI, 10.2-35.6%) and 17.4% (95% CI, 5.4-34.4%) of cases, respectively. 57.3% (95% CI, 33.9-79.0%) of cases showed impairment in liver function after birth, while 55.0% (95% CI, 37.5-71.9%) showed clinical symptoms, mainly due to bile obstruction (47.9% (95% CI, 29.4-66.7%)). Postsurgical complications occurred in 10.9% (95% CI, 3.7-21.3%) of operated cases. Risk assessment according to different cut-offs of cyst size could not be performed in view of the very small number of included studies. CONCLUSIONS: Fetal hepatic cysts are benign, with a low likelihood of associated anomalies of the hepatobiliary tract, abnormal liver function or clinical symptoms. Congenital biliary cysts are associated with a high rate of progression, abnormal liver function after birth and clinical symptoms. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Systematic review and meta-analysis of persistent left superior vena cava on prenatal ultrasound: associated anomalies, diagnostic accuracy and postnatal outcome.

OBJECTIVES: To quantify the prevalence of chromosomal anomalies in fetuses with persistent left superior vena cava (PLSVC), assess the strength of the association between PLSVC and coarctation of the aorta and ascertain the diagnostic accuracy of antenatal ultrasound in correctly identifying isolated cases of PLSVC. METHODS: MEDLINE, EMBASE, CINHAL and the Cochrane databases were searched from the year 2000 onwards using combinations of keywords 'left superior vena cava' and 'outcome'. Two authors reviewed all abstracts independently. Quality assessment of the included studies was performed using the Newcastle-Ottawa Scale for cohort studies. The rates of the following outcomes were analyzed: chromosomal abnormalities; associated intracardiac anomalies (ICAs) and extracardiac anomalies (ECAs) diagnosed prenatally; additional ICAs and ECAs detected only at postnatal imaging or clinical evaluation but missed at prenatal imaging; and association of PLSVC and coarctation of the aorta. Meta-analyses of proportions were used to combine data. RESULTS: In total, 2708 articles were identified and 13 (n = 501) were included in the systematic review. Associated ICAs and ECAs were detected at the prenatal ultrasound examination or at a follow-up assessment in 60.7% (95% CI, 44.2-75.9%) and 37.8% (95% CI, 31.0-44.8%) of cases, respectively. Chromosomal anomalies occurred in 12.5% (95% CI, 9.0-16.4%) of cases in the overall population of fetuses with PLSVC and in 7.0% (95% CI, 2.7-13.0%) of isolated cases. Additional ICAs and ECAs were detected only after birth and missed at ultrasound in 2.4% (95% CI, 0.5-5.8%) and 6.7% (95% CI, 2.2-13.2%) of cases, respectively. Coarctation of the aorta was associated with isolated PLSVC in 21.3% (95% CI, 13.6-30.3%) of cases. CONCLUSIONS: PLSVC is commonly associated with ICAs, ECAs and chromosomal anomalies. Fetuses with isolated PLSVC should be followed up throughout pregnancy in order to rule out coarctation of the aorta. As most of the data in this review were derived from high-risk pregnancies, the rate of associated abnormalities is likely to be higher than that in the general population of fetuses with PLSVC, for which more data are needed. Revisión sistemática y metaanálisis de la persistencia de la vena cava superior izquierda en la ecografía prenatal: anomalías asociadas, precisión del diagnóstico y resultado postnatal RESUMEN OBJETIVOS: Cuantificar la prevalencia de anomalías cromosómicas en fetos con vena cava superior izquierda persistente (VCSIP), evaluar la solidez de la asociación entre la VCSIP y la coartación aórtica, y determinar la precisión del diagnóstico de la ecografía prenatal como método para identificar correctamente casos aislados de VCSIP. MÉTODOS: Se buscó en las bases de datos de MEDLINE, EMBASE, CINHAL y Cochrane artículos publicados desde el año 2000 en adelante, usando combinaciones de las palabras clave "vena cava superior izquierda" y "resultado". Dos de los autores revisaron de forma independiente todos los resúmenes encontrados. La evaluación de calidad de los estudios incluidos se realizó mediante la escala Newcastle-Ottawa para estudios de cohortes. Se analizaron las tasas de los siguientes resultados: anomalías cromosómicas; anomalías intracardíacas (AIC) y anomalías extracardíacas (AEC) asociadas diagnosticadas prenatalmente; AIC y AEC adicionales detectadas sólo en ecografías postnatales o mediante evaluación clínica, pero no observadas en ecografías prenatales; y la asociación entre la VCSIP y la coartación aórtica. Se utilizó un meta-análisis de proporciones para combinar los datos. RESULTADOS: En total, se identificaron 2708 artículos y se incluyeron 13 (n = 501) en la revisión sistemática. En la ecografía prenatal o en una revisión de seguimiento se detectaron AIC y AEC asociadas en el 60,7% (IC 95%, 44,2-75,9%) y el 37,8% (IC 95%, 31,0-44,8%) de los casos, respectivamente. Se produjeron anomalías cromosómicas en el 12,5% (IC 95%, 9,0-16,4%) de los casos en la población general de fetos con VCSIP y en el 7,0% (IC 95%, 2,7-13,0%) de casos aislados. Las AIC y AEC adicionales sólo se detectaron después del nacimiento y en el 6,7% (IC 95%, 2,2-13,2%) de los casos, respectivamente. La coartación aórtica se encontró asociada con la VCSIP aislada en un 21,3% (IC 95%, 13,6-30,3%) de los casos. CONCLUSIONES: La VCSIP está comúnmente asociada a AIC, AEC y anomalías cromosómicas. Los fetos con VCSIP aislada deben ser objeto de seguimiento durante todo el embarazo, con el fin de descartar la coartación aórtica. Como la mayoría de los datos de esta revisión proceden de embarazos de alto riesgo, es probable que la tasa de anomalías asociadas sea más alta que la de la población general de fetos con VCSIP, por lo que se necesitan más datos.

PRES with asymptomatic spinal cord involvement. Is this scenario more common than we know?

INTRODUCTION: Posterior reversible encephalopathy syndrome (PRES) is an entity characterized by neurologic symptoms such as headaches, altered mental status, seizures and visual changes, and it is associated with white matter vasogenic edema predominantly affecting the posterior occipital and parietal lobes of the brain. CASE REPORT: A 19-year-old patient developed PRES after the use of chemotherapy for a testicular teratocarcinoma and after the development of a blood pressure elevation. DISCUSSION: Few cases described the involvement of the spinal cord in this syndrome. In the majority of these cases, the spinal cord involvement was asymptomatic or with few symptoms of spinal cord disease.

Structural studies of the final enzyme in the alpha-aminoadipate pathway-saccharopine dehydrogenase from Saccharomyces cerevisiae.

The 1.64 A structure of the apoenzyme form of saccharopine dehydrogenase (SDH) from Saccharomyces cerevisiae shows the enzyme to be composed of two domains with similar dinucleotide binding folds with a deep cleft at the interface. The structure reveals homology to alanine dehydrogenase, despite low primary sequence similarity. A model of the ternary complex of SDH, NAD, and saccharopine identifies residues Lys77 and Glu122 as potentially important for substrate binding and/or catalysis, consistent with a proton shuttle mechanism. Furthermore, the model suggests that a conformational change is required for catalysis and that residues Lys99 and Asp281 may be instrumental in mediating this change. Analysis of the crystal structure in the context of other homologous enzymes from pathogenic fungi and human sources sheds light into the suitability of SDH as a target for antimicrobial drug development.

The role of tryptophan residues in substrate binding to catalytic domains A and B of xylanase C from Fibrobacter succinogenes S85.

Oxidation of the isolated catalytic domain B of xylanase C (XynC-B) from Fibrobacter succinogenes with N-bromosuccinimide (NBS) resulted in the modification of five of the seven Trp residues present in the enzyme. Hydrolytic activity of the enzyme was rapidly lost upon initiation of oxidation as a molar ratio of about two NBS molecules per molar equivalent of protein was sufficient to cause 50% inhibition of enzyme activity, and the addition of five molar equivalents of NBS resulted in less than 10% activity. Pre-incubation of XynC-B with the competitive inhibitor D-xylose resulted in the apparent protection of two Trp residues from oxidation. Xylose protection of the enzyme also resulted in a maintenance of activity, with 60% activity still evident after addition of 8-9 molar equivalents of NBS. This protection from inactivation was enhanced by the inclusion of xylohexaose in reaction mixtures. Under these conditions, however, a further Trp residue was protected from NBS oxidation. The three protected Trp residues were identified as Trp135, Trp161 and Trp202 by differential labelling and peptide mapping of NBS-oxidized preparations of the xylanase employing a combination of electrospray mass spectroscopic analysis and N-terminal sequencing. By analogy to the known structures of the family 11 xylanases, the fully conserved Trp202 residue is located on the only alpha-helix present in the enzymes, at the interface between it and the back of the beta-sheet which forms the active site cleft. Trp135 represents a highly conserved aromatic residue in family 11, but it is replaced with Thr in domain A of F. succinogenes xylanase C. To investigate the role of Trp135 in conferring the different activity profile of domain B relative to domain A, the Trp135Thr and Trp135Ala derivatives of domain B were prepared by site-directed mutagenesis. However, the kinetic parameters of the two domain B derivatives were not significantly different compared to the wild-type enzyme as reflected by K(M) and k(cat) values and product distribution profiles. Similar results were obtained with the Trp161Ala derivative of domain B, indicating that these two residues do not directly participate in the binding of substrate but likely form the foundation for binding subsite 2.

Characterization of function and activity of domains A, B and C of xylanase C from Fibrobacter succinogenes S85.

Xylanase C from the ruminant bacterium Fibrobacter succinogenes is comprised of two catalytic domains, A and B, and a third domain, C, of unknown function. The DNA coding for domains A and B of xylanase C were separately cloned and expressed in Escherichia coli as fusion proteins with glutathione-S:-transferase. The fusion proteins were isolated by affinity chromatography on glutathione-Sepharose 4B, cleaved with thrombin and the released xylanase C catalytic domains A and B were purified to apparent homogeneity by anion-exchange chromatography on Mono Q. Electrospray mass spectrometry provided a molecular mass of 27 818 Da (expected, 27 820 Da) for domain B. The pH and temperature optima for activity of domain B on oat spelt xylan were 5.0 and 52 degrees C, respectively. A kinetic analysis of the activity of the catalytic domain A on oat spelt xylan, birch wood xylan and xylooligomers at pH 6.5 and 37 degrees C provided data significantly different to those obtained previously with a protease-derived form of the enzyme [Zhu et al. (1994) J. Bacteriol. 176, 3885-3894]. The isolated domain A was more active on barley-glucan than the protease-derived form and its affinity for birch wood xylan was enhanced resulting in greater overall catalytic efficiency as reflected by k(cat)/K:(M) values. Likewise, significant differences in the Michaelis-Menten parameters K:(M), k(cat) and k(cat)/K:(M) were obtained with domain B compared with values previously reported with this domain attached to domain C. In general, the presence of domain C appeared to decrease the overall efficiency of domain B 7- and 36-fold with birch wood xylan and xylopentaose as substrates, respectively, as reflected by values of k(cat)/K:(M). The removal of domain C also affected the mode of action of domain B such that it more closely resembled that of catalytic domain A. However, no change in either pH and temperature optima or stability were found with domain B compared with the combined domains B and C. The function of domain C remains unknown, but hydrophobic cluster analysis indicated that it may belong to a class of dockerin domains involved in the protein-protein interactions of cellulolytic and xylanolytic complexes.

Lysine: N6-hydroxylase: stability and interaction with ligands.

Recombinant lysine:N6-hydroxylase, rIucD, which is isolated as an apoenzyme, requires FAD and NADPH for its catalytic function. rIucD preparations have been found to undergo time-dependent loss in monooxygenase function due to aggregation from the initial tetrameric state to a polytetrameric form(s), a process which is reversible by treatment with thiols. Ligand-induced conformational changes in rIucD were assessed by monitoring its CD spectra, DSC profile, and susceptibility to both endo- as well as exopeptidases. The first two methods indicated the absence of any significant conformational change in rIucD, while the last approach revealed that FAD, and its analog ADP, can protect the protein from the deleterious action of proteases. NADPH was partially effective and L-lysine was ineffective in this regard. Deletion of the C-terminal segment, either by treatment with carboxypeptidase Y or by mutagenesis of iucD, results in the loss of rIucD's monooxygenase activity. These findings demonstrate the crucial role of the C-terminal segment in maintaining rIucD in its native conformation.

Suppression of protein synthesis in brain during hibernation involves inhibition of protein initiation and elongation.

Protein synthesis (PS) has been considered essential to sustain mammalian life, yet was found to be virtually arrested for weeks in brain and other organs of the hibernating ground squirrel, Spermophilus tridecemlineatus. PS, in vivo, was below the limit of autoradiographic detection in brain sections and, in brain extracts, was determined to be 0.04% of the average rate from active squirrels. Further, it was reduced 3-fold in cell-free extracts from hibernating brain at 37 degreesC, eliminating hypothermia as the only cause for protein synthesis inhibition (active, 0.47 +/- 0.08 pmol/mg protein per min; hibernator, 0.16 +/- 0.05 pmol/mg protein per min, P < 0.001). PS suppression involved blocks of initiation and elongation, and its onset coincided with the early transition phase into hibernation. An increased monosome peak with moderate ribosomal disaggregation in polysome profiles and the greatly increased phosphorylation of eIF2alpha are both consistent with an initiation block in hibernators. The elongation block was demonstrated by a 3-fold increase in ribosomal mean transit times in cell-free extracts from hibernators (active, 2.4 +/- 0.7 min; hibernator, 7.1 +/- 1.4 min, P < 0.001). No abnormalities of ribosomal function or mRNA levels were detected. These findings implicate suppression of PS as a component of the regulated shutdown of cellular function that permits hibernating ground squirrels to tolerate "trickle" blood flow and reduced substrate and oxygen availability. Further study of the factors that control these phenomena may lead to identification of the molecular mechanisms that regulate this state.

Effect of selective cysteine --> alanine replacements on the catalytic functions of lysine: N6-hydroxylase.

Recombinant lysine: N6-hydroxylase, rIucD, catalyzes the conversion of L-lysine to its N6-hydroxy derivative. Re-examination of the nucleotide sequence of iucD, the gene encoding for the enzyme, has revealed a few discrepancies in the data documented in literature and the corrected version is presented. The revised nucleotide sequence predicts the presence of five cysteine residues in the primary structure of IucD. Two of these residues, cysteine 51 and cysteine 158 are alkylatable by iodoacetate in the native conformation of the protein resulting in a loss of monooxygenase activity while their replacement with alanine has no such adverse effect. Site directed mutagenesis studies have enabled an assessment of the reactivity of these cysteine residue(s) towards thiol modifying agents.