Is Appendectomy During Late Stages of Pregnancy Associated with an Increased Cesarean Delivery Rate? - a Retrospective Analysis of One Center During 10 Years.

Introduction: About one in 500 pregnant women requires a surgical intervention that is not pregnancy-related. One of the most common surgical interventions during pregnancy is appendectomy. The primary aim of this study was to assess surgical access of appendectomy during pregnancy and pregnancy outcome. Secondary outcomes were clinical symptoms and diagnostics as well as histopathological analysis. Methods and Material: This is a single-center retrospective data analysis conducted at a tertiary perinatal center. A digital search of the hospital record archive was conducted focusing on pregnant women beyond 24 0/7 weeks of pregnancy encoding appendectomy. Descriptive statistical analysis was performed. Results: Between January 2013 and January 2023, a total of 20 appendectomies were performed during pregnancy with gestational age beyond 24 0/7 weeks of pregnancy. All of them were performed as lower midline laparotomy. The rate of appendix perforation was 3/20 (15.0%). 19/20 patients (95.0%) delivered via cesarean. In 7/20 patients (35.0%) appendectomy was performed during cesarean delivery due to incidental finding of irritated or abnormal vermiform appendix. In the pathological work-up, only 2/7 (28.6%) of these subjects had inflammation. Conclusion: In this small monocentric cohort, only open appendectomies were performed. Our data indicate that it is safe to perform open appendectomy during pregnancy if necessary. In this small patient group, there was an increase in simultaneous cesarean deliveries.

Value of ultrasound fusion imaging in detecting vascular cerebral white matter pathology.

BACKGROUND: Transcranial sonography is beside magnetic resonance imaging (MRI) and computed tomography, a well-established imaging method for evaluation of brain parenchyma and already implicated in various neurological disorders as bed-side investigation possibility in clinical routine. The aim of this study was the qualitative assessment detecting vascular white matter hyperintensities (WMHs), with ultrasound fusion-imaging technique (UFI) and to find the optimal location for their visualization in accordance to the grade of WMHs and to possibly providing a standardized protocol for clinical use. RESULTS: 29 patients with WMHs of variable degree quantified according to Fazekas grading scale (n = 13 I; n = 9 II; n = 7 III) and 11 subjects with normal findings on MRI were identified for further analysis. Ultrasound images were analyzed to a standardized protocol and predefined anatomical landmarks. UFI could visualize the MRI-verified WMHs in 147 of 161 localizations (91%). The overall ultrasound detection rate of WMHs increased with higher degree of WMHs burden (I:85%, II:94%, III:97%). The highest sensitivity was achieved at the contralateral central part (CPc) (97%) of the lateral ventricle. The inter-rater analysis between 2 independent raters, who were blinded to the patient's diagnosis and assessed only the B-mode ultrasound images, indicated an 86% agreement with an overall moderate strength of agreement (κ: 0.489, p < 0.0005) for all localizations. The highest accordance within raters was shown at the CPc; 92% (κ: 0.645, p < 0.0005). CONCLUSIONS: This explorative study describes prospectively the ultrasound detection of periventricular vascular WMHs based on MRI lesions using UFI. Transcranial ultrasound (TCS) could serve as an additional screening opportunity for the detection of incidental WMLs during routine TCS investigations to initiate early vascular risk factor modification in primary prevention.

Cerebral autoregulation and brain networks in occlusive processes of the internal carotid artery.

Patients with unilateral occlusive processes of the internal carotid artery (ICA) show subtle cognitive deficits. Decline in cerebral autoregulation and in functional and structural integrity of brain networks have previously been reported in the affected hemisphere (AH). However, the association between cerebral autoregulation, brain networks, and cognition remains to be elucidated. Fourteen neurologically asymptomatic patients (65±11 years) with either ICA occlusion or high-grade ICA stenosis and 11 age-matched healthy controls (HC) (67±6 years) received neuropsychologic testing, transcranial Doppler sonography to assess cerebral autoregulation using vasomotor reactivity (VMR), and magnetic resonance imaging to probe white matter microstructure and resting-state functional connectivity (RSFC). Patients performed worse on memory and executive tasks when compared with controls. Vasomotor reactivity, white matter microstructure, and RSFC were lower in the AH of the patients when compared with the unaffected hemisphere and with controls. Lower VMR of the AH was associated with several ipsilateral clusters of lower white matter microstructure and lower bilateral RSFC in patients. No correlations were found between VMR and cognitive scores. In sum, impaired cerebral autoregulation was associated with reduced structural and functional connectivity in cerebral networks, indicating possible mechanisms by which severe unilateral occlusive processes of the ICA lead to cognitive decline.

Consecutive gene deletions in Mycobacterium smegmatis using the yeast FLP recombinase.

Mycobacteria contain a large number of redundant genes whose functions are difficult to analyze in mutants, because there are only two efficient resistance markers available for allelic exchange experiments. We have established a system based on the Flp recombinase of the yeast Saccharomyces cerevisiae for use in the nonpathogenic model organism Mycobacterium smegmatis. This system consists of a hygromycin resistance cassette flanked by two Flp recognition targets (FRT) in direct orientation and a curable plasmid for expression of the flp gene. The FRT-hyg-FRT cassette was used on a suicide plasmid and on a conditionally replicating plasmid to delete two of the four known porin genes of M. smegmatis, mspA and mspC, respectively, by homologous recombination. The hyg gene was specifically removed from the chromosome of both mutants upon expression of the flp gene. Based on the marker-less mspC mutant strain, a double knock-out mutant lacking also mspA was obtained using the same strategy. Thus, by a fast and efficient two-step procedure, each of the porin genes was replaced by a single FRT site, which can be further used for site-specific integration. These results show that the Flp/FRT system is a suitable genetic tool for constructing unmarked mutations and for the analysis of redundant genes by consecutive gene deletions in M. smegmatis.

DNA-free RNA preparations from mycobacteria.

BACKGROUND: To understand mycobacterial pathogenesis analysis of gene expression by quantification of RNA levels becomes increasingly important. However, current preparation methods yield mycobacterial RNA that is contaminated with chromosomal DNA. RESULTS: After sonication of RNA samples from Mycobacterium smegmatis genomic DNA is efficiently removed by DNaseI in contrast to untreated samples. CONCLUSIONS: This procedure eliminates one of the most prevalent error sources in quantification of RNA levels in mycobacteria.

Dopplersonographic measurement of global cerebral circulation time using echo contrast-enhanced ultrasound in normal individuals and patients with arteriovenous malformations.

Echo-contrast "bolus tracking" by ultrasound (US) is an exciting new tool to study cerebral haemodynamics. In the present study, a global cerebral circulation time (CCT) was measured by extracranial Doppler as the time difference of contrast bolus arrival between the internal carotid artery and internal jugular vein. A total of 64 healthy volunteers and 9 patients with an angiographically diagnosed arteriovenous malformation (AVM) were studied. CCT in volunteers and patients was calculated as the time interval between the points of 10% rise (CCT(1)) and 90% rise (CCT(3)) of the total intensity increase and between the turning points (CCT(2)) of the resulting time-intensity curves. In the volunteer group, CCT(1) was 5.4 +/- 1.8 s, CCT(2) was 7 +/- 1.3 s and CCT(3) 7.5 +/- 1.8 s. CCT results in the AVM group were 2.8 +/- 2.5 s, 3.0 +/- 1.3 s and 4.5 +/- 2.1 s, respectively, and differed significantly from the controls. For the first time, we could confirm a significant shortening of CCT in patients with cerebral AVM by US. The presented test might become a new, additional tool for AVM evaluation and follow-up of treatment in these patients.

Conserved cis-acting elements upstream of genes composing the chitinolytic system of streptomycetes are DasR-responsive elements.

For soil-dwelling bacteria that usually live in a carbon-rich and nitrogen-poor environment, the ability to utilize chitin - the second most abundant polysaccharide on earth - is a decisive evolving advantage as it is a source for both elements. Streptomycetes are high-GC Gram-positive soil bacteria that are equipped with a broad arsenal of chitinase-degrading genes. These genes are induced when the streptomycetes sense the presence of chitooligosaccharides. Their expression is repressed as soon as more readily assimilated carbon sources become available. This includes for example glucose or N-acetylglucosamine, the monomer subunit of chitin. Historically, the first cis-acting elements involved in carbon regulation in streptomycetes were found more than a decade ago upstream of chitinase genes, but the transcriptional regulator had so far remained undiscovered. In this work, we show that these cis-acting elements consist of inverted repeats with multiple occurrences and are bound by the HutC/GntR type regulator DasR. We have therefore designated these sites as DasR-responsive elements (dre). DasR, which is also the repressor of the genes for the N-acetylglucosamine-specific phosphotransferase transport system, should therefore play a critical role in sensing the balance between the monomeric and polymeric forms of N-acetylglucosamine.

A genomic view of sugar transport in Mycobacterium smegmatis and Mycobacterium tuberculosis.

We present a comprehensive analysis of carbohydrate uptake systems of the soil bacterium Mycobacterium smegmatis and the human pathogen Mycobacterium tuberculosis. Our results show that M. smegmatis has 28 putative carbohydrate transporters. The majority of sugar transport systems (19/28) in M. smegmatis belong to the ATP-binding cassette (ABC) transporter family. In contrast to previous reports, we identified genes encoding all components of the phosphotransferase system (PTS), including permeases for fructose, glucose, and dihydroxyacetone, in M. smegmatis. It is anticipated that the PTS of M. smegmatis plays an important role in the global control of carbon metabolism similar to those of other bacteria. M. smegmatis further possesses one putative glycerol facilitator of the major intrinsic protein family, four sugar permeases of the major facilitator superfamily, one of which was assigned as a glucose transporter, and one galactose permease of the sodium solute superfamily. Our predictions were validated by gene expression, growth, and sugar transport analyses. Strikingly, we detected only five sugar permeases in the slow-growing species M. tuberculosis, two of which occur in M. smegmatis. Genes for a PTS are missing in M. tuberculosis. Our analysis thus brings the diversity of carbohydrate uptake systems of fast- and a slow-growing mycobacteria to light, which reflects the lifestyles of M. smegmatis and M. tuberculosis in their natural habitats, the soil and the human body, respectively.

Porins limit the intracellular persistence of Mycobacterium smegmatis.

The genus Mycobacterium comprises highly pathogenic as well as opportunistic or apathogenic species exhibiting a great variability with respect to their ability to persist or multiply within monocytic host cells. The impact of the permeability of the mycobacterial outer membrane on intracellular persistence was studied. For this purpose, a Mycobacterium smegmatis mutant with a deletion of the major porin gene mspA and a second mutant lacking mspA and the homologous porin gene mspC were used. Deletion of mspA together with mspC significantly enhanced intracellular persistence in murine bone marrow macrophages, the mouse macrophage cell line J774A.1 and Acanthamoeba castellanii. Complementation of mspA in the porin mutant strains resulted in restoration of the wild-type phenotype with respect to intracellular persistence. This is the first report to show that the deletion of porins of mycobacteria results in improved persistence in eukaryotic cells, demonstrating that the intracellular persistence of M. smegmatis depends upon the permeability of the outer membrane.

The growth rate of Mycobacterium smegmatis depends on sufficient porin-mediated influx of nutrients.

Mycobacteria have a unique outer membrane (OM) that is thicker than any other known biological membrane. Nutrients cross this permeability barrier by diffusion through porins. MspA is the major porin of Mycobacterium smegmatis. In this study we showed that three paralogues of MspA, namely MspB, MspC and MspD are also porins. However, only the mspA and mspC genes were expressed in the wild-type strain. None of the single deletion mutants displayed a significant OM permeability defect except for the mspA mutant. Deletion of the mspA gene caused activation of transcription of mspB and/or mspD in three independent strains by unknown chromosomal mutations. It is concluded that mspB and mspD provide backup porins for M. smegmatis. This also indicated that a minimal porin-mediated OM permeability is essential for survival of M. smegmatis. Electron microscopy in combination with quantitative image analysis of protein gels revealed that the number of pores per cell dropped from 2400 to 800 and 150 for the DeltamspA and DeltamspA DeltamspC mutant (ML10) respectively. The very low number of pores correlated well with the at least 20-fold lower channel activity of detergent extracts of the ML10 strain and its 15- and 75-fold lower permeability to nutrient molecules such as serine and glucose respectively. The amount of Msp porin and the OM permeability of the triple porin mutant lacking mspA, mspC and mspD was not altered. The growth rate of M. smegmatis dropped drastically with its porin-mediated OM permeability in contrast to porin mutants of Escherichia coli. These results show that porin-mediated influx of nutrients is a major determinant of the growth rate of M. smegmatis.

Multidrug resistance of a porin deletion mutant of Mycobacterium smegmatis.

Mycobacteria contain an outer membrane of unusually low permeability which contributes to their intrinsic resistance to many agents. It is assumed that small and hydrophilic antibiotics cross the outer membrane via porins, whereas hydrophobic antibiotics may diffuse through the membrane directly. A mutant of Mycobacterium smegmatis lacking the major porin MspA was used to examine the role of the porin pathway in antibiotic sensitivity. Deletion of the mspA gene caused high-level resistance of M. smegmatis to 256 microg of ampicillin/ml by increasing the MIC 16-fold. The permeation of cephaloridine in the mspA mutant was reduced ninefold, and the resistance increased eightfold. This established a clear relationship between the activity and the outer membrane permeation of cephaloridine. Surprisingly, the MICs of the large and/or hydrophobic antibiotics vancomycin, erythromycin, and rifampin for the mspA mutant were increased 2- to 10-fold. This is in contrast to those for Escherichia coli, whose sensitivity to these agents was not affected by deletion of porin genes. Uptake of the very hydrophobic steroid chenodeoxycholate by the mspA mutant was retarded threefold, which supports the hypothesis that loss of MspA indirectly reduces the permeability by the lipid pathway. The multidrug resistance of the mspA mutant highlights the prominent role of outer membrane permeability for the sensitivity of M. smegmatis to antibiotics. An understanding of the pathways across the outer membrane is essential to the successful design of chemotherapeutic agents with activities against mycobacteria.

Measurement of global cerebral circulation time using power duplex echo-contrast bolus tracking.

Ultrasound assessment of global cerebral circulation time (CCT) using echo-contrast bolus tracking is a new approach to characterise the perfusion status of the human brain. We present the analysis of global CCT in 36 healthy volunteers and one patient with a cerebral arteriovenous malformation (AVM), measured by extracranial power duplex. CCT was defined as the time interval between bolus arrival in the internal carotid artery and internal jugular vein. CCT in the volunteer group was 7.5 +/- 1.1 s (mean +/- SD). Values did not correlate with age, gender, blood pressure or blood flow velocity. Measurement in the AVM patient revealed a CCT of 1.5 s. Ultrasonographic CCT analysis is a promising new tool for the evaluation of cerebral hemodynamics.