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The D-amino acids glycine, tryptophan and methionine were used to induce AmpC beta lactamase in the ATCC 13047 strain of Enterobacter cloacae. The three amino acids tested induced changes in the peptidoglycan composition and structure. Reduction in peptidoglycan tripeptide levels was also observed. Further, glycine treatment increased the density of diaminopimelic-diaminopimelic cross-links. Methionine also induced changes in the morphology of the bacteria. Further studies suggestthat enzyme activation is brought about by alterations in the peptidoglycan fraction.

In Alzheimer's disease (AD) and tauopathies, tau becomes hyperphosphorylated, undergoes a conformational change, and becomes aggregated and insoluble. There are three methods commonly used to study the insoluble tau fraction, two that utilize detergents (Sarkosyl and RIPA) and another that does not (insoluble). However, these methods require large amounts of homogenate for a relatively low yield of the insoluble fraction, which can be problematic when dealing with small tissue samples. Furthermore, the most common way of analyzing this material is through densitometry of immunoblots, offering only semiquantitative measurements. We provide a comparison of the three methods commonly used (Sarksoyl, RIPA, and insoluble) through immunoblot and ELISA analyses. Finally, we tested a new method to determine aggregated tau levels, utilizing a monoantibody tau ELISA. The insoluble fractions of four different mouse models (P301 L, htau, wild type, and knockout) as well as human AD and control brains were examined. There were significant correlations between the three insoluble methods for both total tau and pS396/404 tau measured by immunoblot or ELISA analyses. Additionally, the results from the ELISA method correlated significantly with those from immunoblot analyses. Finally, the monoantibody assay on the lysate significantly correlated with the total tau ELISAs performed on the three insoluble preparations. Taken together, these results suggest that all three insoluble preparation methods offer similar results for measuring insoluble tau in either mouse or human brains. In addition the new monoantibody ELISA offers a simple quantitative method to measure the amount of aggregated tau in both human and mouse brains. [ABSTRACT FROM AUTHOR]

Ciliopathies are rare congenital disorders caused by defects in the structure or function of cilia, which can lead to a wide range of clinical manifestations. Among them, a subset known as skeletal ciliopathies exhibits significant phenotypic overlap and primarily affects skeletal development. This group includes several syndromes with overlapping but distinct clinical features, such as short-rib polydactyly syndrome (SRPS), Jeune asphyxiating thoracic dystrophy (JATD), Mainzer-Saldino syndrome (MZSDS), and cranioectodermal dysplasia (CED), also called Sensenbrenner syndrome. The most characterized features of skeletal ciliopathies are short stature, rhizomelic limb shortening, and thoracic narrowing to varying extents, with JATD presenting the most severe form. Here, we report a fetus with an extension of skeletal ciliopathy phenotype and compound heterozygous variants in the IFT140 gene. The affected fetus had multiple malformations, including increased nuchal transparency (NT), shortened and thick long bones, hypoplastic tibia and fibula, absence of bladder, flat nose, and frontal bossing. Our findings expand the mutation spectrum of IFT140 , and the clinical spectrum associated with skeletal ciliopathies, highly relevant in diagnosis prenatal settings.

APOE is a major genetic factor in late-onset Alzheimer's disease (LOAD), with APOE4 increasing risk, APOE3 acting as neutral, and APOE2 offering protection. APOE also plays key role in lipid metabolism, affecting both peripheral and central systems, particularly in lipoprotein metabolism in triglyceride and cholesterol regulation. APOE2 is linked to Hyperlipoproteinemia type III (HLP), characterized by mixed hypercholesterolemia and hypertriglyceridemia due to impaired binding to Low-Density Lipoproteins receptors. To explore the impact of human APOE isoforms on LOAD and lipid metabolism, we developed Long-Evans rats with human APOE2, APOE3, or APOE4 in place of rat Apoe. These rats were crossed with those carrying a humanized App allele to express human Aβ, which is more aggregation-prone than rodent Aβ, enabling the study of human APOE-human Aβ interactions. In this study, we focused on 80-day-old adolescent rats to analyze early changes that may be associated with the later development of LOAD. We found that APOE2 hAβ rats had the highest levels of APOE in serum and brain, with no significant transcriptional differences among isoforms, suggesting variations in protein translation or stability. Aβ43 levels were significantly higher in male APOE4 hAβ rats compared to APOE2 hAβ rats. However, no differences in Tau or phosphorylated Tau levels were observed across the APOE isoforms. Neuroinflammation analysis revealed lower levels of IL13, IL4 and IL5 in APOE2 hAβ  males compared to APOE4 hAβ males. Neuronal transmission and plasticity tests using field Input-Output (I/O) and long-term potentiation (LTP) recordings showed increased excitability in all APOE-carrying rats, with LTP deficits in APOE2 hAβ and APOE4 hAβ rats compared to Apoe hAβ and APOE3 hAβ rats. Additionally, a lipidomic analysis of 222 lipid molecular species in serum samples showed that APOE2 hAβ  rats displayed elevated triglycerides and cholesterol, making them a valuable model for studying HLP. These rats also exhibited elevated levels of phosphatidylglycerol, phosphatidylserine, phosphatidylethanolamine, sphingomyelin, and lysophosphatidylcholine. Minimal differences in lipid profiles between APOE3 hAβ and APOE4 hAβ rats reflect findings from mouse models. Future studies will include comprehensive lipidomic analyses in various CNS regions and at older ages to further validate these models and explore the effects of APOE isoforms on lipid metabolism in relation to AD pathology., (© 2024. The Author(s).)

Listeria monocytogenes ( Lm ) is a Gram-positive bacterium causing listeriosis, a rare but severe foodborne infection, particularly impactful during pregnancy. Maternal-fetal transmission can lead to adverse fetal outcomes, yet symptoms in mothers may be nonspecific, delaying intervention. Despite the severity, the mechanisms of vertical transmission remain unclear. This report describes a case of rapid Lm diagnosis in a preterm newborn using cord blood and placental swabs. A 31-week pregnant woman presented with abdominal pain, diarrhea, and reduced fetal movements after consuming raw sushi. Laboratory findings indicated infection, and she vaginally delivered a live infant with placental and fetal abscesses. Cultures confirmed Lm , with swift diagnosis aided by molecular syndromic testing. The neonate received appropriate antibiotics and was asymptomatic by the end of treatment. This case underscores the need for the rapid diagnosis of maternal-fetal listeriosis, as it poses significant risks during pregnancy, including preterm birth and neonatal complications. Current diagnostic methods often delay treatment. This report emphasizes the use of innovative molecular techniques for early diagnosis, which is crucial in managing neonatal infections, especially in preterm newborns., (© 2024 The Authors.)