Prediction by uterine artery Doppler screening of small-for-gestational-age neonates at 19-24 weeks' gestation.

OBJECTIVE: Small-for-gestational-age (SGA) neonates are at increased risk of perinatal mortality and morbidity. We aimed to investigate the performance of uterine artery pulsatility index (UtA-PI) at 19-24 weeks' gestation to predict the delivery of a SGA neonate in a Chinese population. METHODS: This was a retrospective cohort study using data obtained between January 2010 and June 2018. Doppler ultrasonography was performed at 19-24 weeks' gestation. SGA was defined as birth weight below the 10th centile according to the INTERGROWTH-21st fetal growth standards. The performance of UtA-PI to predict the delivery of a SGA neonate was assessed using receiver-operating-characteristics (ROC)-curve analysis. RESULTS: We included 6964 singleton pregnancies, of which 748 (11%) delivered a SGA neonate, including 115 (15%) women with preterm delivery. Increased UtA-PI was associated with an elevated risk of SGA, both in neonates delivered at or after 37 weeks' gestation (term SGA) and those delivered before 37 weeks (preterm SGA). The areas under the ROC curve (AUCs) for UtA-PI were 64.4% (95% CI, 61.5-67.3%) and 75.8% (95% CI, 69.3-82.3%) for term and preterm SGA, respectively. The performance of combined screening by maternal demographic/clinical characteristics and estimated fetal weight in the detection of term and preterm SGA was improved significantly by the addition of UtA-PI, although the increase in AUC was modest (2.4% for term SGA and 4.9% for preterm SGA). CONCLUSIONS: This is the first Chinese study to evaluate the role of UtA-PI at 19-24 weeks' gestation in the prediction of the delivery of a neonate with SGA. The addition of UtA-PI to traditional risk factors improved the screening performance for SGA, and this improvement was greater in predicting preterm SGA compared with term SGA. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

[Effect of non-breathing-related sleep fragmentation on cognitive function in patients with cerebral small vessel disease].

Objective: To investigate the effect of non-breathing-related sleep fragmentation on cognitive function in patients with atherosclerotic cerebral small vessel disease(CSVD). Methods: Seventy-two patients with arteriosclerotic CSVD in the Department of Neurology, the Third Affiliated Hospital of Sun Yat-sen University were enrolled in this study from August 2017 to July 2018. The patients undertook MRA(Magnetic Resonance Angiography)+SWI(Susceptibility weighted imaging), polysomnography, Montreal Cognitive Inventory (MoCA) and Concise Mental State Examination (MMSE). The patients were divided into study group (≥19) and control group (<19) according to the median number of arousal events (median=19) at night. Results: The sleep efficiency, rapid eye movement (REM) sleep ratio and non-rapid eye movement-3 (NREM-3) sleep ratio of the study group were significantly lower than those of the control group (P<0.05), and the total MoCA score (18.2±4.3) , visual space score(1.9±1.4) and delayed recall score(1.4±0.9) of the study group were significantly lower than those of the control group (22.7±3.5, 2.9±1.2, 2.9±1.1, P<0.05). Conclusion: The incidence of non-breathing-related sleep fragmentation is high in CSVD patients and this kind of fragmentation is associated with cognitive impairment.

Identification and reproducibility of diagnostic DNA markers for tuber starch and yield optimization in a novel association mapping population of potato (Solanum tuberosum L.).

KEY MESSAGE: SNPs in candidate genes Pain - 1, InvCD141 (invertases), SSIV (starch synthase), StCDF1 (transcription factor), LapN (leucine aminopeptidase), and cytoplasm type are associated with potato tuber yield, starch content and/or starch yield. Tuber yield (TY), starch content (TSC), and starch yield (TSY) are complex characters of high importance for the potato crop in general and for industrial starch production in particular. DNA markers associated with superior alleles of genes that control the natural variation of TY, TSC, and TSY could increase precision and speed of breeding new cultivars optimized for potato starch production. Diagnostic DNA markers are identified by association mapping in populations of tetraploid potato varieties and advanced breeding clones. A novel association mapping population of 282 genotypes including varieties, breeding clones and Andean landraces was assembled and field evaluated in Northern Spain for TY, TSC, TSY, tuber number (TN) and tuber weight (TW). The landraces had lower mean values of TY, TW, TN, and TSY. The population was genotyped for 183 microsatellite alleles, 221 single nucleotide polymorphisms (SNPs) in fourteen candidate genes and eight known diagnostic markers for TSC and TSY. Association test statistics including kinship and population structure reproduced five known marker-trait associations of candidate genes and discovered new ones, particularly for tuber yield and starch yield. The inclusion of landraces increased the number of detected marker-trait associations. Integration of the present association mapping results with previous QTL linkage mapping studies for TY, TSC, TSY, TW, TN, and tuberization revealed some hot spots of QTL for these traits in the potato genome. The genomic positions of markers linked or associated with QTL for complex tuber traits suggest high multiplicity and genome wide distribution of the underlying genes.

Rapid detection of urinary tract infections using isotachophoresis and molecular beacons.

We present a novel assay for rapid detection and identification of bacterial urinary tract infections using isotachophoresis (ITP) and molecular beacons. We applied on-chip ITP to extract and focus 16S rRNA directly from bacterial lysate and used molecular beacons to achieve detection of bacteria specific sequences. We demonstrated detection of E. coli in bacteria cultures as well as in patient urine samples in the clinically relevant range 1E6-1E8 cfu/mL. For bacterial cultures we further demonstrate quantification in this range. The assay requires minimal sample preparation (a single centrifugation and dilution), and can be completed, from beginning of lysing to detection, in under 15 min. We believe that the principles presented here can be used for design of other rapid diagnostics or detection methods for pathogenic diseases.

Foot pressure and center of pressure in athletes with ankle instability during lateral shuffling and running gait.

This study evaluates foot pressure and center of pressure (COP) patterns in individuals with ankle instability during running and lateral shuffling. Eleven participants with ankle instability (AI) and 11 normal subjects (Normal) performed running and lateral shuffling tasks. The outcome measures were foot progression angle, peak pressure, and displacement of COP during stance phase. During running, the foot progression angle, that is, the angle of foot abduction, was lower in the AI group (Normal: 13.46° ± 4.45°; AI: 8.78° ± 3.91°), and the 1st metatarsal contact pressure (Normal: 0.76 ± 0.47 N/cm(2)·kg; AI: 1.05 ± 0.70 N/cm(2)·kg) and the 3rd metatarsal peak pressure were higher in the AI (Normal: 0.96 ± 0.60 N/cm(2)·kg; AI: 1.54 ± 0.68 N/cm(2)·kg). The medial-lateral (M-L) COP in the late-stance phase of running for the AI group transferred faster from lateral to medial foot than the Normal group. For lateral shuffling, the AI group had greater peak pressure at the 1st (Normal: 0.76 ± 0.67 N/cm(2)·kg; AI: 1.49 ± 1.04 N/cm(2)·kg), 2nd (Normal: 0.57 ± 0.39 N/cm(2)·kg; AI: 0.87 ± 0.68 N/cm(2)·kg), 3rd (Normal: 0.70 ± 0.54 N/cm(2)·kg; AI: 1.42 ± 0.87 N/cm(2)·kg), and 4th (Normal: 0.52 ± 0.38 N/cm(2)·kg; AI: 1.12 ± 0.78 N/cm(2)·kg) metatarsal areas than the Normal group. The M-L COP located more laterally from the early to mid-stance phase in the AI compared with the Normal group. The findings suggest that COP displacement during lateral shuffle may be a factor in ankle instability while the foot progression angle during running may be a compensatory strategy.

Metabolic engineering of Escherichia coli for 1-butanol and 1-propanol production via the keto-acid pathways.

Production of higher alcohols via the keto-acid intermediates found in microorganism's native amino-acid pathways has recently shown promising results. In this work, an Escherichia coli strain that produces 1-butanol and 1-propanol from glucose was constructed. The strain first converts glucose to 2-ketobutyrate, a common keto-acid intermediate for isoleucine biosynthesis. Then, 2-ketobutyrate is converted to 1-propanol through reactions catalyzed by the heterologous decarboxylase and dehydrogenase, or to 1-butanol via the chemistry involved in the synthesis of the unnatural amino acid norvaline. We systematically improved the synthesis of 1-propanol and 1-butanol through deregulation of amino-acid biosynthesis and elimination of competing pathways. The final strain demonstrated a production titer of 2 g/L with nearly 1:1 ratio of butanol and propanol.

Rapid Microbiology Screening in Pharmaceutical Workflows.

Recently advances in miniaturization and automation have been utilized to rapidly decrease the time to result for microbiology testing in the clinic. These advances have been made due to the limitations of conventional culture-based microbiology methods, including agar plate and microbroth dilution, which have long turnaround times and require physicians to treat patients empirically with antibiotics before test results are available. Currently, there exist similar limitations in pharmaceutical sterility and bioburden testing, where the long turnaround times associated with standard microbiology testing drive costly inefficiencies in workflows. These include the time lag associated with sterility screening within drug production lines and the warehousing cost and time delays within supply chains during product testing. Herein, we demonstrate a proof-of-concept combination of a rapid microfluidic assay and an efficient cell filtration process that enables a path toward integrating rapid tests directly into pharmaceutical microbiological screening workflows. We demonstrate separation and detection of Escherichia coli directly captured and analyzed from a mammalian (i.e., CHO) cell culture with a 3.0 h incubation. The demonstration is performed using a membrane filtration module that is compatible with sampling from bioreactors, enabling in-line sampling and process monitoring.

Engineered synthetic pathway for isopropanol production in Escherichia coli.

A synthetic pathway was engineered in Escherichia coli to produce isopropanol by expressing various combinations of genes from Clostridium acetobutylicum ATCC 824, E. coli K-12 MG1655, Clostridium beijerinckii NRRL B593, and Thermoanaerobacter brockii HTD4. The strain with the combination of C. acetobutylicum thl (acetyl-coenzyme A [CoA] acetyltransferase), E. coli atoAD (acetoacetyl-CoA transferase), C. acetobutylicum adc (acetoacetate decarboxylase), and C. beijerinckii adh (secondary alcohol dehydrogenase) achieved the highest titer. This strain produced 81.6 mM isopropanol in shake flasks with a yield of 43.5% (mol/mol) in the production phase. To our knowledge, this work is the first to produce isopropanol in E. coli, and the titer exceeded that from the native producers.

Improving lycopene production in Escherichia coli by engineering metabolic control.

Metabolic engineering has achieved encouraging success in producing foreign metabolites in a variety of hosts. However, common strategies for engineering metabolic pathways focus on amplifying the desired enzymes and deregulating cellular controls. As a result, uncontrolled or deregulated metabolic pathways lead to metabolic imbalance and suboptimal productivity. Here we have demonstrated the second stage of metabolic engineering effort by designing and engineering a regulatory circuit to control gene expression in response to intracellular metabolic states. Specifically, we recruited and altered one of the global regulatory systems in Escherichia coli, the Ntr regulon, to control the engineered lycopene biosynthesis pathway. The artificially engineered regulon, stimulated by excess glycolytic flux through sensing of an intracellular metabolite, acetyl phosphate, controls the expression of two key enzymes in lycopene synthesis in response to flux dynamics. This intracellular control loop significantly enhanced lycopene production while reducing the negative impact caused by metabolic imbalance. Although we demonstrated this strategy for metabolite production, it can be extended into other fields where gene expression must be closely controlled by intracellular physiology, such as gene therapy.

Down-regulation of miR-342-3p in hepatocellular carcinoma tissues and its prognostic significance.

OBJECTIVE: The involvement of microRNAs in cancer and their potential as biomarkers of prognosis are becoming increasingly appreciated. The aim of this study was to evaluate the clinical importance and prognostic value of miR-342-3p in hepatocellular carcinoma (HCC). PATIENTS AND METHODS: RT-PCR was used to detect the expression of miR-342-3p. The association with clinicopathologic features was analyzed. Kaplan-Meier survival analysis and Cox proportional hazards analysis were used to compare the overall survival between HCC patients with high miR-342-3p expression and those with low miR-342-3p expression. RESULTS: We found that miR-342-3p expression was significantly decreased in HCC tissues compared with paired adjacent non-tumor tissues (p < 0.001). MiR-342-3p expression was correlated with histologic grade (p = 0.008) and tumor TNM stage (p = 0.001). Kaplan-Meier survival analysis showed that patients in the high miR-342-3p expression group had better overall survival than those in the low miR-342-3p expression group (p < 0.001). Univariate analysis showed that miR-342-3p (p = 0.001), TNM stage (p = 0.002) and histologic grade (p = 0.006) were associated with poor survival rates. Multivariate analysis confirmed that miR-342-3p expression can be used as an independent predictor for HCC prognosis (p = 0.002). CONCLUSIONS: miR-342-3p may serve as a tumor suppressor during HCC progression, and its low expression may be a potential biomarker for poor prognosis of HCC.

Microbial pathway engineering for industrial processes: evolution, combinatorial biosynthesis and rational design.

Microbial pathway engineering has made significant progress in multiple areas. Many examples of successful pathway engineering for specialty and fine chemicals have been reported in the past two years. Novel carotenoids and polyketides have been synthesized using molecular evolution and combinatorial strategies. In addition, rational design approaches based on metabolic control have been reported to increase metabolic flux to specific products. Experimental and computational tools have been developed to aid in design, reconstruction and analysis of non-native pathways. It is expected that a hybrid of evolutionary, combinatorial and rational design approaches will yield significant advances in the near future.

Issues in cDNA microarray analysis: quality filtering, channel normalization, models of variations and assessment of gene effects.

We consider the problem of comparing the gene expression levels of cells grown under two different conditions using cDNA microarray data. We use a quality index, computed from duplicate spots on the same slide, to filter out outlying spots, poor quality genes and problematical slides. We also perform calibration experiments to show that normalization between fluorescent labels is needed and that the normalization is slide dependent and non-linear. A rank invariant method is suggested to select non-differentially expressed genes and to construct normalization curves in comparative experiments. After normalization the residuals from the calibration data are used to provide prior information on variance components in the analysis of comparative experiments. Based on a hierarchical model that incorporates several levels of variations, a method for assessing the significance of gene effects in comparative experiments is presented. The analysis is demonstrated via two groups of experiments with 125 and 4129 genes, respectively, in Escherichia coli grown in glucose and acetate.

Macrophage arginase promotes tumor cell growth and suppresses nitric oxide-mediated tumor cytotoxicity.

Macrophages use L-arginine to synthesize nitric oxide (NO) and polyamines through the inducible NO synthase (iNOS) and arginase, respectively. The released NO contributes to the tumoricidal activity of macrophages, whereas polyamines may promote the growth of tumor cells. Both the tumoricidal and growth-promoting activities from macrophages have been reported; however, the underlying mechanisms for switching between this dual function of macrophages remain unclear. Here, we test the hypothesis that arginase participates in the switching between the cytotoxic and growth-promoting activities of macrophages toward tumor cells. To alter arginase activity in macrophages, cells (murine macrophage cell line J774A.1) were transfected with the rat liver arginase gene or treated with an arginase inhibitor, L-norvaline. The effects of macrophage arginase activity on the growth-promoting and cytotoxic activities of macrophages toward breast tumor cells (ZR-75-1) were investigated in a coculture system. The results demonstrated that overexpression of arginase in macrophages enhanced L-ornithine and putrescine production and consequently promoted tumor cell proliferation. This proliferative effect was down-regulated by the arginase inhibitor L-norvaline. Furthermore, increases in arginase activity also attenuated NO production by the lipopolysaccharide-activated macrophages and thus reduced the cytotoxic effect on cocultured tumor cells. Inhibiting arginase activity by L-norvaline effectively reversed the suppression of NO-mediated tumor cytotoxicity. Together, these results suggest that arginase induction in macrophages can enhance tumor cell growth by providing them with polyamines and suppress tumor cytotoxicity by reducing NO production. It appears that L-arginine metabolism through the arginase and iNOS pathways in macrophages can have very different influences on the growth of nearby tumor cells depending on which pathway is prevailing.

Fish optimize sensing and respiration during undulatory swimming.

Previous work in fishes considers undulation as a means of propulsion without addressing how it may affect other functions such as sensing and respiration. Here we show that undulation can optimize propulsion, flow sensing and respiration concurrently without any apparent tradeoffs when head movements are coupled correctly with the movements of the body. This finding challenges a long-held assumption that head movements are simply an unintended consequence of undulation, existing only because of the recoil of an oscillating tail. We use a combination of theoretical, biological and physical experiments to reveal the hydrodynamic mechanisms underlying this concerted optimization. Based on our results we develop a parsimonious control architecture that can be used by both undulatory animals and machines in dynamic environments.

Modelling and analysis of metabolic pathways.

Modelling and analysis of metabolic pathways has received an increasing amount of attention over the past few years. Progress has been made in many aspects such as the identification of rate-controlling steps, applications of optimization principles, and stoichiometric analyses. In addition, the scope of modelling has also expanded. These efforts have led to an improved understanding of metabolic pathways and have facilitated their manipulation.

Dynamic metabolic control theory. A methodology for investigating metabolic regulation using transient metabolic data.

The purposes of the dynamic metabolic control theory are to provide a theoretical basis for estimating the control coefficients using the transient metabolic responses and to gain insights into the metabolic regulation in the transient states. The numerical application of this theory is relatively straightforward: it involves a standard linear regression and a matrix multiplication. Although the equations are exact only for linear kinetics, they yield relatively good estimates of the control coefficients for nonlinear systems.

Alteration of the biochemical valves in the central metabolism of Escherichia coli.

Although E. coli central metabolism has been studied for several decades, many regulatory features are still unknown. To achieve the goal of rational manipulation of cellular metabolism, it is important to understand how E. coli responds to overexpressed enzymes. By studying the biochemical control of fluxes between PEP, pyruvate, and OAA, we have addressed some fundamental questions that may prove to be essential for applications in metabolic engineering. First, we found that simultaneous overexpression of Pck and Ppc, or Pps alone in the presence of glucose leads to phenotypes consistent with futile cycline. In contrast to our expectation, futile cycling per se does not affect the growth rate significantly. However, excessive futile cycling may cause competitive disadvantage in the natural environment. Overexpression of Pck caused growth inhibition but no futile cycling. Therefore, E. coli controls the expression of gluconeogenic enzymes not only to avoid excessive futile cycling, but also to prevent toxicity effects. In metabolic engineering, futile cycling may be used as a strategy to stimulate metabolism for either production of metabolites or digestion of toxic wastes. Second, we found that the expression levels of Pps and Pck in E. coli are not optimal for growth on pyruvate and succinate, respectively. Overexpression of these enzymes increases the growth rate on pyruvate and on succinate, respectively, indicating that the slow growth rates on these substrates are at least partially caused by the insufficient supply of PEP and its derivatives. Moreover, E. coli also has not optimized the Ppc level for optimal growth yield on glucose in uncontrolled batch cultures. These results demonstrate that the central metabolism is not optimized for growth under defined laboratory conditions. Thus, the possibility exists that adjustment of native enzyme levels in the central metabolism can improve bioreactor performance. Third, we found that overexpression of Pck affects the transcriptional levels of unrelated genes. This example indicates that physiological responses to enzyme (over)expression should be interpreted cautiously, as changing the expression level of a specific enzyme may affect many unlinked genes. Similar results have also been obtained by use of two-dimensional electrophoresis of proteins from E. coli. Although more questions remain to be answered, fast progress in the area of metabolic engineering can be expected in the near future.

Red blood cell sorbitol lowering effects and tolerance of single doses of AL 1576 (HOE 843) in diabetic patients.

The safety and biochemical effects of AL 1576 (HOE 483), a recently developed aldose reductase inhibitor, were evaluated. In a double-blind, placebo-controlled, clinical trial, AL 1576 (HOE 483) was administered to diabetic patients for the first time. Four single, orally administered dose levels were tested, (2, 5, 10, and 20 mg). No clinically important adverse effects were seen in any of the patients. AL 1576 (HOE 483) suppressed red blood cell (RBC) sorbitol concentrations in a dose-related fashion. Also found were statistically significant inverse correlations between the plasma drug concentration and both RBC sorbitol concentrations as well as RBC sorbitol/serum glucose ratios. In single doses up to 20 mg, AL 1576 (HOE 483) is well tolerated and decreases RBC sorbitol, a biochemical marker of pharmacologic activity, in diabetic patients.

Chromophore-assisted laser inactivation of subunits of the T-cell receptor in living cells is spatially restricted.

Chromophore-assisted laser inactivation (CALI) is a molecular photoablation technique that has been used to elucidate the in vivo roles of specific proteins in neural development. The interpretation of its effects on proteins in living cells relies on knowing how spatially restricted the CALI-induced damage is in vivo. To determine the spatial specificity of CALI in living cells, we have applied CALI to individual subunits of the T-cell receptor (TCR) complex on the surface of 2B4 hybridoma cells in culture and have examined the consequent structural and functional integrity of the TCR-alpha, TCR-beta and CD3-epsilon. The CALI of TCR-beta resulted in the disruption of the beta subunit and also resulted in a small effect on antibody binding alone to the neighboring TCR-alpha but caused no effect on another subunit, CD3-epsilon. Reciprocal experiments directing CALI to TCR-alpha and CD3-epsilon gave consistent results. No effects other than a simple loss of function were observed for any of these CALI experiments. These data demonstrate the extent of CALI-induced damage within a multisubunit complex in living cells and provide greater confidence for the future application of this technique to understanding in vivo function of proteins during complex cellular processes.

Gene expression profiling by DNA microarrays and metabolic fluxes in Escherichia coli.

DNA microarray technology was applied to detect differential transcription profiles of a subset of the Escherichia coli genome. A total of 111 E. coli genes, including those in central metabolism, key biosyntheses, and some regulatory functions, were cloned, amplified, and used as probes for detecting the level of transcripts. An E. coli strain was grown in glucose, acetate, and glycerol media, and the transcript levels of the selected genes were detected. Despite extensive studies on E. coli physiology, many new features were found in the regulation of these genes. For example, several genes were unexpectedly up-regulated, such as pps, ilvG, aroF, secA, and dsbA in acetate and asnA and asnB in glycerol, or down-regulated, such as ackA, pta, and adhE in acetate. These genes were regulated with no apparent reasons by unknown mechanisms. Meanwhile, many genes were regulated for apparent purposes but by unknown mechanisms. For example, the glucose transport genes (ptsHI, ptsG, crr) in both acetate and glycerol media were down-regulated, and the ppc, glycolytic, and biosynthetic genes in acetate were also down-regulated because of the reduced fluxes. However, their molecular mechanisms remain to be elucidated. Furthermore, a group of genes were regulated by known mechanisms, but the physiological roles of such regulation remain unclear. This group includes pckA and aspA, which are up-regulated in glycerol, and gnd and aspA, which are down- and up-regulated, respectively, in acetate. The DNA microarray technology demonstrated here is a powerful yet economical tool for characterizing gene regulation and will prove to be useful for strain improvement and bioprocess development.