Association of umbilical vein flow with abnormal fetal growth and adverse perinatal outcome in low-risk population: multicenter prospective study.

OBJECTIVES: To investigate the relationship of umbilical vein flow (UVF) measured close to term with abnormal fetal growth and adverse perinatal outcome in a cohort of pregnancies at low risk of placental insufficiency. METHODS: This was a prospective multicenter observational study conducted across two tertiary maternity units. Patients with a singleton appropriate-for-gestational-age fetus between 35 and 38 weeks' gestation were included. Pregnancies at higher risk of placental insufficiency or with fetal anomalies were excluded. At ultrasound examination, the abdominal circumference (AC), umbilical vein diameter and peak velocity of the umbilical vein were measured, and, using these variables, a new variable, UVF/AC, was calculated. The primary outcome was the occurrence of severely stunted fetal growth, defined as a greater than 40-percentile drop between estimated fetal weight at the third-trimester ultrasound and birth weight between the third-trimester ultrasound and delivery. The occurrence of adverse perinatal outcome, defined as one of the following: neonatal acidosis (umbilical artery pH < 7.15 and/or base excess > 12 mmol/L) at birth, 5-min Apgar score < 7, neonatal resuscitation or neonatal intensive care unit admission, was analyzed as a secondary outcome. RESULTS: Between April 2021 and March 2023, 365 women were included in the study. The mean UVF/AC at enrolment was 6.4 ± 2.6 mL/min/cm, and 35 (9.6%) cases were affected by severely stunted fetal growth. Severely stunted fetal growth was associated with a lower mean UVF/AC (5.4 ± 2.6 vs 6.5 ± 2.6 mL/min/cm; P = 0.02) and a higher frequency of UVF/AC < 10th percentile (8/35 (22.9%) vs 28/330 (8.5%); P = 0.01). Moreover, UVF/AC showed an area under the receiver-operating-characteristics curve (AUC) of 0.65 (95% CI, 0.55-0.75; P = 0.004) in predicting the occurrence of severely stunted fetal growth, and the optimal cut-off value of UVF/AC for discriminating between normal and severely stunted fetal growth was 7.2 mL/min/cm. This value was associated with a sensitivity and specificity of 0.77 (95% CI, 0.60-0.90) and 0.33 (95% CI, 0.28-0.39), and positive and negative predictive values of 0.11 (95% CI, 0.07-0.15) and 0.93 (95% CI, 0.87-0.97), respectively. Regarding the occurrence of adverse perinatal outcome, this was associated independently with maternal age (adjusted odds ratio (aOR), 0.93 (95% CI, 0.87-0.99); P = 0.04), UVF/AC Z-score (aOR, 0.53 (95% CI, 0.30-0.87); P = 0.01) and augmentation of labor (aOR, 2.69 (95% CI, 1.28-5.69); P = 0.009). UVF/AC showed an AUC of 0.65 (95% CI, 0.56-0.73; P = 0.005) in predicting the occurrence of adverse perinatal outcome, and the optimal cut-off value of UVF/AC for discriminating between normal and adverse perinatal outcome was 6.7 mL/min/cm. This value was associated with a sensitivity and specificity of 0.70 (95% CI, 0.54-0.83) and 0.40 (95% CI, 0.34-0.45), and positive and negative predictive values of 0.14 (95% CI, 0.09-0.19) and 0.91 (95% CI, 0.85-0.95), respectively. CONCLUSIONS: Our data demonstrate an association between reduced UVF close to term, severely stunted fetal growth and adverse perinatal outcome in a cohort of low-risk pregnant women, with a moderate ability to rule out and a poor ability to rule in either outcome. Further studies are needed to establish whether the assessment of UVF can improve the identification of fetuses at risk of subclinical placental insufficiency and adverse perinatal outcome. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Mode of delivery and peripartum outcome in women with heart disease according to the ESC guidelines: an Italian multicenter study.

INTRODUCTION: The European Society of Cardiology (ESC) guidelines (GL) provide indications on the mode of delivery in women with heart disease. However available data suggests that the rate of Cesarean Delivery (CD) is high and widely variable among such patients. In this study, we aimed to investigate the degree of adherence to the ESC recommendations among women delivering in four tertiary maternity services in Italy and how this affects the maternal and neonatal outcomes. MATERIAL AND METHODS: Retrospective multicenter cohort study including pregnant women with heart disease who gave birth between January 2014 and July 2020. Composite adverse maternal outcome (CAM) was defined by the occurrence of one or more of the following: major postpartum hemorrhage, thrombo-embolic or ischemic event, de novo arrhythmia, heart failure, endocarditis, aortic dissection, need for re-surgery, sepsis, maternal death. Composite Adverse Neonatal outcome (CAN) was defined as cord arterial pH <7.00, APGAR <7 at 5 min, admission to the intensive care unit, and neonatal death. We compared the incidence of CAM and CAN between the cases with planned delivery in accordance (group "ESC consistent") or in disagreement (group "ESC not consistent") with the ESC GL. RESULTS: Overall, 175 women and 181 liveborn were included. A higher frequency of CAN was found when delivery was not planned accordingly to the ESC guidelines [("ESC consistent" 9/124 (7.2%) vs "ESC not consistent" 13/57 (22.8%) p = 0.002 OR 3.74 (CI 95% 1.49-9.74) , while the occurrence of CAM was comparable between the two groups. At logistic regression analysis, the gestational age at delivery was the only parameter independently associated with the occurrence of CAN (p = 0.006). CONCLUSION: Among pregnant women with heart disease, deviating from the ESC guidelines scheduling cesarean delivery does not seem to improve maternal outcomes and it is associated with worse perinatal outcomes, mainly due to lower gestational age at birth.

New technique for automatic sonographic measurement of change in head-perineum distance and angle of progression during active phase of second stage of labor.

OBJECTIVE: To evaluate the performance of a new ultrasound technique for the automatic assessment of the change in head-perineum distance (delta-HPD) and angle of progression (delta-AoP) during the active phase of the second stage of labor. METHODS: This was a prospective observational cohort study including singleton term pregnancies with fetuses in cephalic presentation during the active phase of the second stage of labor. In each patient, two videoclips of 10 s each were acquired transperineally, one in the axial and one in the sagittal plane, between rest and the acme of an expulsive effort, in order to measure HPD and AoP, respectively. The videoclips were processed offline and the difference between the acme of the pushing effort and rest in HPD (delta-HPD) and AoP (delta-AoP) was calculated, first manually by an experienced sonographer and then using a new automatic technique. The reliability of the automatic algorithm was evaluated by comparing the automatic measurements with those obtained manually, which was considered as the reference gold standard. RESULTS: Overall, 27 women were included. A significant correlation was observed between the measurements obtained by the automatic and the manual methods for both delta-HPD (intraclass correlation coefficient (ICC) = 0.97) and delta-AoP (ICC = 0.99). The high accuracy provided by the automatic algorithm was confirmed by the high values of the coefficient of determination (r2 = 0.98 for both delta-HPD and delta-AoP) and the low residual errors (root mean square error = 1.2 mm for delta-HPD and 1.5° for delta-AoP). A Bland-Altman analysis showed a mean difference of 0.52 mm (limits of agreement, -1.58 to 2.62 mm) for delta-HPD (P = 0.034) and 0.35° (limits of agreement, -2.54 to 3.09°) for delta-AoP (P = 0.39) between the manual and automatic measurements. CONCLUSIONS: The automatic assessment of delta-AoP and delta-HPD during maternal pushing efforts is feasible. The automatic measurement of delta-AoP appears to be reliable when compared with the gold standard manual measurement by an experienced operator. Copyright © 2020 ISUOG. Published by John Wiley & Sons Ltd.

Exploiting microbial hyperthermophilicity to produce an industrial chemical, using hydrogen and carbon dioxide.

Microorganisms can be engineered to produce useful products, including chemicals and fuels from sugars derived from renewable feedstocks, such as plant biomass. An alternative method is to use low potential reducing power from nonbiomass sources, such as hydrogen gas or electricity, to reduce carbon dioxide directly into products. This approach circumvents the overall low efficiency of photosynthesis and the production of sugar intermediates. Although significant advances have been made in manipulating microorganisms to produce useful products from organic substrates, engineering them to use carbon dioxide and hydrogen gas has not been reported. Herein, we describe a unique temperature-dependent approach that confers on a microorganism (the archaeon Pyrococcus furiosus, which grows optimally on carbohydrates at 100°C) the capacity to use carbon dioxide, a reaction that it does not accomplish naturally. This was achieved by the heterologous expression of five genes of the carbon fixation cycle of the archaeon Metallosphaera sedula, which grows autotrophically at 73°C. The engineered P. furiosus strain is able to use hydrogen gas and incorporate carbon dioxide into 3-hydroxypropionic acid, one of the top 12 industrial chemical building blocks. The reaction can be accomplished by cell-free extracts and by whole cells of the recombinant P. furiosus strain. Moreover, it is carried out some 30°C below the optimal growth temperature of the organism in conditions that support only minimal growth but maintain sufficient metabolic activity to sustain the production of 3-hydroxypropionate. The approach described here can be expanded to produce important organic chemicals, all through biological activation of carbon dioxide.

Regulation of iron metabolism by Pyrococcus furiosus.

Iron is an essential element for the hyperthermophilic archaeon Pyrococcus furiosus, and many of its iron-containing enzymes have been characterized. How iron assimilation is regulated, however, is unknown. The genome sequence contains genes encoding two putative iron-responsive transcription factors, DtxR and Fur. Global transcriptional profiles of the dtxR deletion mutant (ΔDTXR) and the parent strain under iron-sufficient and iron-limited conditions indicated that DtxR represses the expression of the genes encoding two putative iron transporters, Ftr1 and FeoAB, under iron-sufficient conditions. Under iron limitation, DtxR represses expression of the gene encoding the iron-containing enzyme aldehyde ferredoxin oxidoreductase and a putative ABC-type transporter. Analysis of the dtxR gene sequence indicated an incorrectly predicted translation start site, and the corrected full-length DtxR protein, in contrast to the truncated version, specifically bound to the promoters of ftr1 and feoAB, confirming its role as a transcription regulator. Expression of the gene encoding Ftr1 was dramatically upregulated by iron limitation, but no phenotype was observed for the ΔFTR1 deletion mutant under iron-limited conditions. The intracellular iron concentrations of ΔFTR1 and the parent strain were similar, suggesting that under the conditions tested, Ftr1 is not an essential iron transporter despite its response to iron. In contrast to DtxR, the Fur protein appears not to be a functional regulator in P. furiosus, since it did not bind to the promoters of any of the iron-regulated genes and the deletion mutant (ΔFUR) revealed no transcriptional responses to iron availability. DtxR is therefore the key iron-responsive transcriptional regulator in P. furiosus.

Impact of environmental changes and human-related factors on the potential malaria vector, Anopheles labranchiae (Diptera: Culicidae), in Maremma, Central Italy.

The Maremma Plain (central Italy) was hyper-endemic for malaria until the mid-20th century, when a national campaign for malaria elimination drastically reduced the presence of the main vector Anopheles labranchiae Falleroni. However, the introduction of rice cultivation over 30 yr ago has led to an increase in the An. labranchiae population and concern over possible malaria reemergence. We studied the impact of anthropogenic environmental changes on the abundance and distribution of An. labranchiae in Maremma, focusing on rice fields, the main breeding sites. Adults and larvae were collected in three main areas with diverse ecological characteristics. Data were collected on human activity, land use, and seasonal climatic and demographic variations. We also interviewed residents and tourists regarding their knowledge of malaria. Our findings showed that the most important environmental changes have occurred along the coast; An. labranchiae foci are present throughout the area, with massive reproduction strictly related to rice cultivation in coastal areas. Although the abundance of this species has drastically decreased over the past 30 yr, it remains high and, together with climatic conditions and the potential introduction of gametocyte carriers, it may represent a threat for the occurrence of autochthonous malaria cases. Our findings suggest the need for the continuous monitoring of An. labranchiae in the study area. In addition to entomological surveillance, more detailed knowledge of human-induced environmental changes is needed, so as to have a more complete database that can be used for vector-control plans and for properly managing emergencies related to autochthonous introduced cases.

Metals in biology: defining metalloproteomes.

The vital nature of metal uptake and balance in biology is evident in the highly evolved strategies to facilitate metal homeostasis in all three domains of life. Several decades of study on metals and metalloproteins have revealed numerous essential bio-metal functions. Recent advances in mass spectrometry, X-ray scattering/absorption, and proteomics have exposed a much broader usage of metals in biology than expected. Even elements such as uranium, arsenic, and lead are implicated in biological processes as part of an emerging and expansive view of bio-metals. Here we discuss opportunities and challenges for established and newer approaches to study metalloproteins with a focus on technologies that promise to rapidly expand our knowledge of metalloproteins and metal functions in biology.

Robust, high-throughput solution structural analyses by small angle X-ray scattering (SAXS).

We present an efficient pipeline enabling high-throughput analysis of protein structure in solution with small angle X-ray scattering (SAXS). Our SAXS pipeline combines automated sample handling of microliter volumes, temperature and anaerobic control, rapid data collection and data analysis, and couples structural analysis with automated archiving. We subjected 50 representative proteins, mostly from Pyrococcus furiosus, to this pipeline and found that 30 were multimeric structures in solution. SAXS analysis allowed us to distinguish aggregated and unfolded proteins, define global structural parameters and oligomeric states for most samples, identify shapes and similar structures for 25 unknown structures, and determine envelopes for 41 proteins. We believe that high-throughput SAXS is an enabling technology that may change the way that structural genomics research is done.

[Dermatofibrosarcoma protuberans: surgical treatment using the Tübingen technique (31 cases)]. / Dermatofibrosarcome de Darier-Ferrand: traitement par la technique chirurgicale de Tübingen (31 cas).

BACKGROUND: Dermatofibrosarcoma protuberans is a rare cutaneous sarcoma that progresses slowly. Although it exhibits pronounced local aggressiveness, it rarely metastasises. The condition is difficult to treat on account of asymmetric and unpredictable growth as well as the frequency of relapse. Treatment is primarily surgical. PATIENTS AND METHODS: We report 31 cases of dermatofibrosarcoma protuberans operated at the Dermatology Clinic of Novara between 1997 and 2004 using the Tübingen technique. An immunohistochimical study was performed and screening was carried out for possible extension of the neoplasm into muscle. RESULTS: Muscular involvement was seen in 4 cases. No relapses were seen over a median survival period of 3 years and no patients were lost to follow-up. DISCUSSION: The Mohs technique is the surgical method of reference and allows tumour eradication with sparing of healthy tissue. The Tübingen method constitutes an alternative approach requiring fewer histological sections. The results obtained in our series were good and no relapses were seen over a median survival period of 3 years.

Computational studies of competitive inhibitors of nitric oxide synthase (NOS) enzymes: towards the development of powerful and isoform-selective inhibitors.

Crystallographic structures of wild-type and mutant NOS isoforms complexed with substrate, intermediate, inhibitor, cofactor, and cofactor analogs are currently available. However, because of the high level of amino-acid conservation and the consequent similarity in dimeric quaternary structure as well as in the active site of NOS isoforms, structure-based isoform-selective inhibitor design is still a very challenging task. Nevertheless, the comprehension of the structural determinants for selectivity among the isoforms is fundamental for the design of further potent and more selective inhibitors. Computational techniques, based on the knowledge of the tridimensional structure of the isozymes, have been already applied to understand the significant isoform selectivity shown by some compounds. Collectively these structure-based approaches, in combination with SAR studies, have been able to explain the structural reasons of this selectivity.

Structure of the prolidase from Pyrococcus furiosus.

The structure of prolidase from the hyperthermophilic archaeon Pyrococcus furiosus (Pfprol) has been solved and refined at 2.0 A resolution. This is the first structure of a prolidase, i.e., a peptidase specific for dipeptides having proline as the second residue. The asymmetric unit of the crystals contains a homodimer of the enzyme. Each of the two protein subunits has two domains. The C-terminal domain includes the catalytic site, which is centered on a dinuclear metal cluster. In the as-isolated form of Pfprol, the active-site metal atoms are Co(II) [Ghosh, M., et al. (1998) J. Bacteriol. 180, 4781-9]. An unexpected finding is that in the crystalline enzyme the active-site metal atoms are Zn(II), presumably as a result of metal exchange during crystallization. Both of the Zn(II) atoms are five-coordinate. The ligands include a bridging water molecule or hydroxide ion, which is likely to act as a nucleophile in the catalytic reaction. The two-domain polypeptide fold of Pfprol is similar to the folds of two functionally related enzymes, aminopeptidase P (APPro) and creatinase. In addition, the catalytic C-terminal domain of Pfprol has a polypeptide fold resembling that of the sole domain of a fourth enzyme, methionine aminopeptidase (MetAP). The active sites of APPro and MetAP, like that of Pfprol, include a dinuclear metal center. The metal ligands in the three enzymes are homologous. Comparisons with the molecular structures of APPro and MetAP suggest how Pfprol discriminates against oligopeptides and in favor of Xaa-Pro substrates. The crystal structure of Pfprol was solved by multiple-wavelength anomalous dispersion. The crystals yielded diffraction data of relatively high quality and resolution, despite the fact that one of the two protein subunits in the asymmetric unit was found to be significantly disordered. The final R and R(free) values are 0.24 and 0.28, respectively.

The effects of graded administration of positive end expiratory pressure on the fluid filtration rate in isolated rabbit lungs, using normal lungs, hydrostatic oedema lungs and oleic acid induced oedema.

The influence of positive end expiratory pressure (PEEP) on the fluid filtration rate (FFR) in the pulmonary circulation has been the subject of considerable investigation but data are conflicting. We studied twenty-nine isolated rabbit lung preparations, FFR was sensed by a force transducer. Autologous blood was used to prime the perfusion circuit. Hydrostatic oedema was achieved by increasing the left atrial pressure to 16 mmHg. In order to bring about increased membrane permeability oleic acid was injected through the pulmonary artery. Increasing and decreasing levels of PEEP at 0, 5, 10 and 15 cm H2O were each used for ten minutes in each of three experimental models. The FFR, pH, mean pulmonary arterial pressure (MPAP), mean left atrial pressure (MLAP), PaO2, PaCO2 and oncotic pressure were measured in each experiment. There was a significant correlation between PEEP and FFR (+0.94) in non-oedema lungs. With no PEEP the FFR was 0 g/min and with 15 cm of PEEP it increased to 0.07 g/min, on removing the PEEP the FFR returned to 0 g/min. In the hydrostatic lung oedema model the correlation was also significant but negative (r = -0.94). With no PEEP the FFR was 0.33 g/min, with PEEP of 15 cm H2O it decreased to 0.08 g/min. No correlation between PEEP and FFR was found in the oleic acid preparation. In the normal lung PEEP increases capillary hydrostatic pressure and total lung vascular area and decreases interstitial pressure. It is by these mechanisms that PEEP causes an increase in FFR. In the hydrostatic oedema model PEEP decreases FFR by increasing the interstitial pressure and by decreasing the total lung vascular area. In the oleic acid preparation the coefficient of filtration is so large that small changes in pressure or vascular area do not modify the FFR. We suggest that PEEP may be beneficial by decreasing FFR in hydrostatic lung oedema, but it may increase the FFR in the normal lung, while having no effect in oleic acid lung injury.