Search

Introduction: Gestational diabetes mellitus (GDM) is a common metabolic disorder linked to adverse pregnancy outcomes. Recent research indicates that HbA1c is reliable in detecting maternal glycemia during the first trimester but may underestimate glucose intolerance in the late second to third trimesters. Therefore, it is reasonable to hypothesize that mothers with GDM, despite apparently normal HbA1c levels in the third trimester, may give birth to infants displaying characteristic features often seen in infants of diabetic mothers with suboptimal glycemic control. This study aimed to describe a case series of autopsy cases involving stillborn or deceased neonates delivered in the third trimester to mothers diagnosed with GDM and having normal HbA1c levels at or around the time of delivery. The primary focus was on identifying and documenting the characteristic features commonly associated with “infants of diabetic mothers” with suboptimal glycemic control in this series of cases.Materials and Methods: We conducted a retrospective review of autopsy reports from our institution spanning 7.5 years. The study included cases that met the following criteria: (1) stillborn or infants who died in the early neonatal period, delivered in the third trimester; (2) mothers diagnosed with GDM; (3) normal maternal HbA1c levels of ≤6.1% at or around the time of delivery; (4) birthweight or femoral length exceeding the 90th percentile for gestational age; and (5) absence of genetic aberrations. We also examined these cases for other characteristic features associated with “infants of diabetic mothers.”Results: Ten autopsy cases met our inclusion criteria, including 9 stillbirths and 1 neonatal death. Gestational age at delivery ranged from 32 to 39 weeks (mean: 35.7 weeks). Femoral length exceeded the 90th percentile in all cases, and 6 cases had birthweights above the 90th percentile. Puffy facies were observed in 6 cases. Among the 9 cases with complete autopsies including internal examination, 6 exhibited excess adipose tissue, 4 had cardiomegaly, and 3 showed pancreatic islet hyperplasia. Hypoxic-ischemic encephalopathy was detected in 7 cases. No structural abnormalities were noted.Discussion: Our findings demonstrated that fetuses and neonates born to mothers with apparently normal HbA1c levels in the third trimester could still display characteristic features commonly observed in infants of diabetic mothers with poor glycemic control, also known as “infants of diabetic mothers.” This study underscores the potential of third-trimester maternal HbA1c measurements to underestimate maternal glycemia and its consequential impact on fetal development, as well as the subsequent manifestation of features of “infants of diabetic mothers.”

Background 4-11% of umbilical cords contain vitelline vessel remnants (VVRs). A recent study has described neutrophilic inflammation arising from VVRs and suggested an association with amniotic fluid infection (AFI).Methods During routine placental pathology sign-out over a six month period, we identified 70 cords with VVRs. HE-stained sections were re-examined for “VVR-derived funisitis,” which was classified as low or high grade/stage based upon whether neutrophils were present only in Wharton’s jelly near the VVRs or whether neutrophils were also present near the cord’s amniotic surface. The same placentas were also examined for histologic evidence of AFI (maternal response = acute chorionitis or chorioamnionitis vs. fetal response = chorionic vasculitis, umbilical vasculitis, or funisitis vs. both).Results Neutrophilic inflammation arising from VVRs was present in 54.3% (38/70); 15 and 23 lesions were low and high grade/stage, respectively. “VVR-derived funisitis” was strongly associated with histological evidence of AFI elsewhere in the placenta. Its overall sensitivity and specificity were 0.94 and 0.88; when VVR-derived funisitis was high grade/stage or diagnosed in the third trimester, specificity rose to 1.0.Conclusion “VVR-derived funisitis” has a strong association with histological evidence of AFI.

This study provides a discussion on the applications and limitations of ¹⁵NH4⁺ metabolic labeling in proteomic studies. The hyperthemophilic crenarchaeon Sulfolobus solfataricus was used as a model organism throughout this study. The distribution of nitrogen was studied in four different experiments in which this distribution was manipulated in a unique way. The experiments included full adaptation to media with relative isotope abundances (RIA) of 0.36%, 50%, and >98% ¹⁵NH4⁺. The incorporation efficiency was calculated on the basis of a comparison between theoretical and experimental spectra. In the case of full adaptation, incorporation efficiencies reflected the RIA (0.36%, 47.5% and 99% respectively). Labeling efficiencies were calculated on the basis of peak areas in TOF-MS spectra. It is shown that in the case of full adaptation, labeling efficiencies are 100%. In addition, we demonstrate that ¹⁵NH4⁺ labeling can be used in protein turnover studies, even when labeling is incomplete. In this case, incorporation efficiencies of 88−93% (lower than the RIA) were measured, providing evidence for amino acid recycling. Labeling efficiencies were always between 63% and 94% providing evidence for protein degradation. Finally, it was shown that isotope distributions can be useful in peptide identification. Keywords: metabolic labeling • protein turnover • proteomics • archaea • Sulfolobus solfataricus

After a successful off-line feasibility study, the automation of comprehensively coupled liquid chromatography and gas chromatography (LC×GC) has been studied. Important aspects to consider when developing automated LG×GC include the relative speeds of the two dimensions, the compatibility of the LC eluent (type and flow rate) with the GC dimension, and the column loadabilities. Because the GC separation is relatively slow, the LC instrument has to be operated in the stop-flow mode. Two interfaces for transferring large numbers of subsequent LC fractions to the GC were constructed: one based on a six-port switching valve, and one which uses a dual side-port syringe. Both interfaces were found to perform fully acceptably. The actual transfer of the LC fraction to the GC was realised using a standard split injector to vaporise the compounds and LC eluent. Gas phase splitting was applied to match LC mass load and GC column loadability. The standard deviations of the peak areas obtained in this way were better than 7% (n = 6). The reliability of the system was demonstrated by the problem-free analysis of large series of oil and fat samples, with the focus on both intact triglycerides and their fatty acid methyl esters (FAMEs). Finally, the hyphenation of the automated LC×GC system to a sensitive and rapid-scanning time-of-flight mass spectrometer was realised. By using LC×GC–ToF MS, the information density of the chromatograms could be improved even further, which allowed easy identification of individual compounds as well as compound groups.

Anhydrous zirconium(IV) and tin(IV) sulfate [Zr(SO₄)₂ and Sn(SO₄)₂] were prepared from their corresponding metal tetrachlorides and fuming H₂SO₄/10% SO₃. Properties of interest for their potential use as heterogeneous Lewis acid catalysts, such as their susceptibility to undergo hydrolysis, are studied. In the presence of water the metal sulfates are converted into their metal oxides (ZrO₂ ·2H₂O and SnO₂·2H₂O) and the Brønsted acid H₂SO₄, which can also be catalytically active. This is illustrated by the solvent-free liquid-phase hydro-acyloxy-addition of acetic acid (2) to camphene (1) (molar ratio 1: 2 = 1:1) giving the fragrance isobornyl acetate (3). Both anhydrous Zr(SO₄)₂ and Sn(SO₄)₂ are inactive as heterogeneous solid Lewis acid catalysts; no conversion of 1 into 3 is found. Upon addition of water, however, 1 is efficiently converted into 3. Moreover, the conversion of 1 into 3 continues even after removal of the solid Lewis acid catalyst by filtration. These results show that after addition of water the reaction becomes homogeneously catalysed by dissolved H₂SO₄.

Teleomorphic, or sexual, phases have not been described for many deuteromycetous fungi and it is debated whether these phases actually exist, or are even necessary for some fungi. Muller's Ratchet is a population genetical mechanism, hypothesized in 1964 by H. J. Muller, which describes how certain asexual populations may undergo an unavoidable and progressive decline in fitness, eventually leading to population extinction. With respect to deuteromycetous fungi, Muller's Ratchet could operate because clonally reproducing populations are not able to reduce their mutational load with each generation. Here we used a model to investigate and quantify some of the potential effects of the lack of sexual recombination on the accumulation of deleterious mutations using parameters derived from two species of deuteromycetous entomopathogenic fungi, Metarhizium anisopliae and Beauveria bassiana. Our results suggest that, under certain realistic conditions, Muller's Ratchet may not play a critical role in the fitness of these deuteromycetous entomopathogenic fungi and it is at least theoretically possible that these fungi could reproduce through exclusive clonal lineages.

A new method is presented to segment vessels in 3D MRA data, based on the wavefront propagation algorithm. We will compare the results to conventional X-ray DSA, and we will show our 3D visualization and interaction platform.

Objectives : To determine the accuracy of a new software for automated quantitative 3D magnetic resonance angiography (MRA) analysis and to validate the findings with corresponding measurement on maximal intensity projection (MIP) images and digital subtraction angiography (DSA) images. Furthermore, to determine the inter-observer variability on carotid artery measurements using the three different methods. Methods : A retrospective review of arch angiograms and carotid first-pass, gadolinium-enhanced 3D-MRA, was performed on 10 patients. Common carotid arteries were measured by two individual investigators using DSA and MRA images. Inter-observer variability and the correlation between DSA, automated MRA evaluation and evaluation on MIP images was determined. Results : Inter-observer agreement on common carotid artery measurements was excellent for DSA and automated MRA evaluation. For each observer, comparison between DSA and automated MRA evaluation showed no statistically significant difference, whereas on MIP measurements, greater discrepancies were shown. Conclusions : Automated MRA evaluation allows reproducible measurements of carotid arteries between different observers. It can be used as an accurate method for analyzing vessel dimensions based on MRA images.

A 909 bp region containing a genomic clone encoding for hydrophobin (ssgA) from the entomopathogenic fungus Metarhizium anisopliae has been sequenced and the regulatory motifs analysed against those recognized in other fungi. The genomic clone was also compared with the open reading frame of the hydrophobin ssgA (starvation stress gene) cDNA sequence. The genomic clone contained a 291 bp coding sequence with one intron of 64 nucleotides. From this sequence primers were established that could be used to amplify the hydrophobin. Restriction fragment polymorphism analysis of hydrophobin amplified by the polymerase chain reaction from 80 isolates of M. anisopliae showed no variability. Analysis of the potential regulatory elements 313 bp upstream from the transcriptional start site revealed typical TATAA and CCAAT boxes. CT or GC motifs were not found. Upstream regulatory elements were also found with sequence homologies to the AREA, CREA, CRE (cAMP response element) and BRLA regions of Aspergillus nidulans as well as the CYS3 and AmyB regions of Aspergillus oryzae. The promoter regions of other fungal hydrophobins were also assessed for the presence of regulatory elements. Upstream regulatory elements are also present for the gene encoding a cuticle-degrading protease (Pr1) from M. anisopliae. We suggest that nutrient levels and cAMP mediation of thigmotropic signals in the entomopathogenic fungus, M. anisopliae, co-ordinate the regulation of the gene products required for morphological development and secretion of ‘penetration’ enzymes.

A biochemical model is presented that describes growth of Methylosinus trichosporium OB3b on methane. The model, which was developed to compare strategies to alleviate NADH limitation resulting from cometabolic contaminant conversion, includes (1) catabolism of methane via methanol, formaldehyde, and formate to carbon dioxide; (2) growth as formaldehyde assimilation; and (3) storage material (poly-β-hydroxybutyric acid, PHB) metabolism. To integrate the three processes, the cofactor NADH is used as central intermediate and controlling factor&sbd;instead of the commonly applied energy carrier ATP. This way a stable and well-regulated growth model is obtained that gives a realistic description of a variety of steady-state and transient-state experimental data. An analysis of the cells' physiological properties is given to illustrate the applicability of the model. Steady-state model calculations showed that in strain OB3b flux control is located primarily at the first enzyme of the metabolic pathway. Since no adaptation in VMAX values is necessary to describe growth at different dilution rates, the organism seems to have a “rigid enzyme system”, the activity of which is not regulated in response to continued growth at low rates. During transient periods of excess carbon and energy source availability, PHB is found to accumulate, serving as a sink for transiently available excess reducing power.

A metabolic model describing growth of Methylosinus trichosporium OB3b and cometabolic contaminant conversion is used to optimize trichloroethene (TCE) conversion in a bioreactor system. Different process configurations are compared:  a growing culture and a nongrowing culture to which TCE is added at both constant and pulsed levels. The growth part of the model, presented in the preceding article, gives a detailed description of the NADH regeneration required for continued TCE conversion. It is based on the metabolic pathways, includes Michaelis−Menten type enzyme kinetics, and uses NADH as an integrating and controlling factor. Here the model is extended to include TCE transformation, incorporating the kinetics of contaminant conversion, the related NADH consumption, toxic effects, and competitive inhibition between TCE and methane. The model realistically describes the experimentally observed negative effects of the TCE conversion products, both on soluble methane monooxygenase through the explicit incorporation of the activity of this enzyme and on cell viability through the distinction between dividing and nondividing cells. In growth-based systems, the toxicity of the TCE conversion products causes rapid cell death, which leads to wash-out of suspended cultures at low TCE loads (below μM inlet concentrations). Enzyme activity, which is less sensitive, is hardly affected by the toxicity of the TCE conversion products and ensures high conversions (>95%) up to the point of wash-out. Pulsed addition of TCE (0.014−0.048 mM) leads to a complete loss of viability. However, the remaining enzyme activity can still almost completely convert the subsequently added large TCE pulses (0.33−0.64 mM). This emphasizes the inefficient use of enzyme activity in growth-based systems. A comparison of growth-based and similar non-growth-based systems reveals that the highest TCE conversions per amount of cells grown can be obtained in the latter. Using small amounts of methane (negligible compared to the amount needed to grow the cells), NADH limitation in the second step of this two-step system can be eliminated. This results in complete utilization of enzyme activity and thus in a very effective treatment system.

In the present study, a fully automated solid-phase extraction (SPE) system, a programmed temperature vaporization (PTV) interface, and gas chromatography (GC) with mass spectrometric (MS) detection are combined for the trace-level analysis of micropollutants in surface water. The PTV interface is selected because of its reliability regarding large volume injection and its robustness when analyzing real-life samples. The mass spectrometer was used both in the full-scan and the selected ion monitoring modes and gave detection limits of about 15–40 ng/L and 0.7–5 ng/L (7.5-mL samples), respectively, for a series of NP-pesticides. © 2000 John Wiley & Sons, Inc. J Micro Sep 12: 153–159, 2000

The breakdown of dissolved TCE in a two-step bioremediation system is described. In the first reactor, the organism Methylosinus trichosporium OB3b is grown; in the second reactor, consisting of three 17-L column reactors in series, the cells degrade TCE. A special design allowed both for the addition of air (uG,s = 0.01–0.04 mm s⁻¹) in the conversion reactor to prevent oxygen limitation while minimizing stripping of TCE, and for the use of methane as exogenous electron donor. In two-step systems presented thus far, only formate was used (excess, 20 mM). We found formate additions could be reduced by 75% (15°C), whereas small amounts of methane (0.02–0.04 mol CH4/g cells) could replace formate and led to equally optimal results. Example calculations show that up to 90% reduction in operating cost of chemicals can be obtained by using methane instead of formate. A model was developed to describe each of the conditions studied: excess formate and optimal methane addition, suboptimal formate addition and suboptimal methane addition. Using parameters obtained from independent batch experiments, the model gives a very good description of the overall TCE conversion in the two-step system. The system presented is flexible (oxygen/methane addition) and can easily be scaled up for field application. The model provides a tool for the design of an effective and low-cost treatment system based on methane addition in the conversion reactor. © 1999 John Wiley & Sons, Inc. Biotechnol Bioeng 63: 56–68, 1999.

A randomized screening trial was started in Europe to show the effect of early detection and treatment of prostate cancer on mortality (European Study on Screening of Prostate Cancer). In one centre (Rotterdam), the screening protocol initially consisted of 3 screening tests for all men: prostate-specific antigen (PSA), digital rectal examination (DRE) and transrectal ultrasonography (TRUS). A PSA value of ≥4 ng/ml and/or an abnormality on DRE and/or TRUS were taken to indicate that biopsy was required. In this study, we examined the possibilities for a more efficient screening protocol. A logistic-regression model was used to predict the number of cancers for PSA < 4 ng/ml if all men were biopsied (predictive index, PI). Effects of a change in PSA cut-off on the screening results were explored. Weights were applied to procedures and cancers to explore the possibility of expressing differences between protocols in one overall figure. Biopsies in men with PSA < 1 ng/ml and a positive DRE or TRUS were very inefficient. Applying DRE and TRUS only in the PSA ranges 1.5 to 3.9 and 2 to 3.9 ng/ml to determine whether a biopsy was required would result in a decrease of 29 to 36% in biopsies and a decrease of 5 to 8% in cancers. However, the results of DRE and TRUS could not be duplicated entirely. A protocol with only PSA ≥ 3 ng/ml as a direct biopsy indicator resulted in a decrease of detected cancers by 7.6% and of biopsies by 12%, also a much simpler screening procedure. Use of the PI would give more efficient protocols, but this should be viewed as a preliminary finding, with the disadvantage of necessitating many additional screening visits. Since the results of DRE and TRUS could not be duplicated, a change in protocol towards PSA ≥ 3 ng/ml appears acceptable. If this proves effective, a final judgement about the optimal combination of screening tests may be made. Int. J. Cancer (Pred. Oncol.) 84:437–441, 1999. © 1999 Wiley-Liss, Inc.

Several mutations in the tau gene have been found in families with hereditary frontotemporal dementia and parkinsonism linked to chromosome 17q21-22 (FTDP-17). This study is the first attempt to correlate genotype and phenotype in six families with FTDP-17 with mutations in the tau gene (ΔK280, G272V, P301L, and R406W). We have investigated tau pathology in 1 P301L and 1 R406W patient. The R406W family showed a significantly higher age at onset (59.2 ± 5.5 years) and longer duration of illness (12.7 ± 1.5 years) than the families with the other mutations. The six families showed considerable variation in clinical presentation, but none of them had early parkinsonism. Mutism developed significantly later in the R406W family than in the other families. Frontotemporal atrophy on neuroimaging in the R406W family was less severe than in the P301L and ΔK280 families. The P301L brain contained many pretangles in the frontal and temporal cortex, and the dentate gyrus of hippocampus, showing three tau bands (64, 68, and 72 kd) of extracted tau from the frontal cortex. The presence of many neurofibrillary tangles, many diffuse and classic neuritic plaques in the temporal and parietal cortex, and the hippocampus of the same P301L brain correlated with the presence of four sarkosyl-insoluble (60, 64, 68, and 72 kd) tau bands. The coexistence of characteristic P301L and Alzheimer pathology in the same brain needs further explanation. The R406W brain showed abundant neurofibrillary tangles in several brain regions, and four tau bands (60, 64, 68, and 72 kd) of extracted tau from these regions. The slower progression of the disease in the R406W family might be explained by the microtubule-binding properties of the mutant protein.

We studied the diagnostic accuracy of single-photon emission computed tomography (SPECT) with technetium 99m-labeled hexamethylpropylene amine oxime (Tc 99m HMPAO) in 48 patients with probable Alzheimer's disease (AD) according to NINCDS-ADRDA criteria and in 60 controls recruited from a population-based study. With logistic regression, we identified decreased temporal regional cerebral blood flow as the best discriminating variable between patients and controls. Receiver-operator characteristic curves showed that the discriminative ability of SPECT improved with increasing dementia severity. With specificity set at 90, sensitivity figures were 42 in mild, 56 in moderate, and 79 in severe AD. The diagnostic gain as a function of the prior probability of the disease being present was computed for those with mild AD. When the prior probability varied at around 50, the diagnostic gain for mild AD patients was substantial (a maximum of 34) for a positive test result but poor for a negative test result. The results suggest that the practical usefulness of SPECT as a diagnostic adjunct in patients suspected of having mild AD is confined to situations in which, on clinical grounds, there is considerable diagnostic doubt.

Lewis acid catalyzed allylic substitutions with several nucleophiles at C-5 of the cis-tetracarbonyliron complexes of N-acetyl- and N-tosyl-5-(R)-isopropoxy-3-pyrrolin-2-ones occur highly regio- and stereoselectively. The results are interpreted as being indicative of the intermediacy of a (π-allyl)tetracarbonyliron cation, with possible preceding formation of an N-acyl- or an N-tosyliminium ion.

Several isomeric prostaglandin F1aanalogues in which the cyclopentane moiety is replaced by a cyclohexane ring, have been prepared starting from the Diels–Alder adduct of 1,4-diacetoxy-1,3-butadiene and dimethyl fumarate.