Regional differences in the in vivo synthesis and degradation of myosin subunits in rabbit ventricular myocardium.

Abstract. The in vivo synthesis of thromboxane A2 and prostacyclin was estimated in 23 diabetics through measurements of the major urinary metabolites 2,3-dinor-thromboxane B2 and 2,3-dinor-6-keto-PGF1α utilizing gas chromatography-mass spectrometry. Mean excretion was similar to that in non-diabetic subjects. The possible influence of hyperglycemia on the excretion of 2,3-dinor-thromboxane B2 and 2,3-dinor-6-keto-PGF1α was evaluated in three ways: by measuring excretion before and during an acute 9-h normalization of hyperglycemia through an artificial pancreas (Biostator) as well as by comparing excretion before and 7–12 days or 40–180 days after the initiation of insulin treatment. Despite significant reducing effects on hyperglycemia or on levels of hemoglobin A1c, no effects on the excretion of the thromboxane and prostacyclin metabolites could be found. Abnormal formation of thromboxane or prostacyclin is not a generalized feature of the diabetic state.

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Oral Administration of Starting Materials for In Vivo Synthesis of Antibacterial Gold Nanoparticles for Curing Remote Infections

Nano Letters ◽

10.1021/acs.nanolett.0c04578 ◽

2021 ◽

Vol 21 (2) ◽

pp. 1124-1131

Author(s):

Le Wang ◽

Junchuan Yang ◽

Sixiang Li ◽

Qizhen Li ◽

Shaoqin Liu ◽

...

Keyword(s):

Gold Nanoparticles ◽

Oral Administration ◽

In Vivo Synthesis

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Bioorthogonal strategies for the in vivo synthesis or release of drugs

Bioorganic & Medicinal Chemistry ◽

10.1016/j.bmc.2021.116310 ◽

2021 ◽

pp. 116310

Author(s):

Boris Lozhkin ◽

Thomas R. Ward

Keyword(s):

In Vivo Synthesis

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Cortical neurons exhibit diverse myelination patterns that scale between mouse brain regions and regenerate after demyelination

Nature Communications ◽

10.1038/s41467-021-25035-2 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Cody L. Call ◽

Dwight E. Bergles

Keyword(s):

Cortical Neurons ◽

Regional Differences ◽

Brain Regions ◽

Axon Diameter ◽

Neuronal Identity ◽

Cortical Areas ◽

Myelin Sheaths ◽

Parvalbumin Interneurons ◽

Selection Of

ABSTRACTAxons in the cerebral cortex show a broad range of myelin coverage. Oligodendrocytes establish this pattern by selecting a cohort of axons for myelination; however, the distribution of myelin on distinct neurons and extent of internode replacement after demyelination remain to be defined. Here we show that myelination patterns of seven distinct neuron subtypes in somatosensory cortex are influenced by both axon diameter and neuronal identity. Preference for myelination of parvalbumin interneurons was preserved between cortical areas with varying myelin density, suggesting that regional differences in myelin abundance arises through local control of oligodendrogenesis. By imaging loss and regeneration of myelin sheaths in vivo we show that myelin distribution on individual axons was altered but overall myelin content on distinct neuron subtypes was restored. Our findings suggest that local changes in myelination are tolerated, allowing regenerated oligodendrocytes to restore myelin content on distinct neurons through opportunistic selection of axons.

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In vivo synaptic density relates to glucose metabolism at rest in healthy subjects, but is strongly modulated by regional differences

Journal of Cerebral Blood Flow & Metabolism ◽

10.1177/0271678x20981502 ◽

2021 ◽

pp. 0271678X2098150

Author(s):

June van Aalst ◽

Jenny Ceccarini ◽

Stefan Sunaert ◽

Patrick Dupont ◽

Michel Koole ◽

...

Keyword(s):

Glucose Metabolism ◽

Medial Temporal Lobe ◽

Regional Differences ◽

Specific Binding ◽

Aerobic Glycolysis ◽

Glucose Consumption ◽

Brain Regions ◽

Synaptic Density ◽

Energy Demands

Preclinical and postmortem studies have suggested that regional synaptic density and glucose consumption (CMRGlc) are strongly related. However, the relation between synaptic density and cerebral glucose metabolism in the human brain has not directly been assessed in vivo. Using [11C]UCB-J binding to synaptic vesicle glycoprotein 2 A (SV2A) as indicator for synaptic density and [18F]FDG for measuring cerebral glucose consumption, we studied twenty healthy female subjects (age 29.6 ± 9.9 yrs) who underwent a single-day dual-tracer protocol (GE Signa PET-MR). Global measures of absolute and relative CMRGlc and specific binding of [11C]UCB-J were indeed highly significantly correlated ( r > 0.47, p < 0.001). However, regional differences in relative [18F]FDG and [11C]UCB-J uptake were observed, with up to 19% higher [11C]UCB-J uptake in the medial temporal lobe (MTL) and up to 17% higher glucose metabolism in frontal and motor-related areas and thalamus. This pattern has a considerable overlap with the brain regions showing different levels of aerobic glycolysis. Regionally varying energy demands of inhibitory and excitatory synapses at rest may also contribute to this difference. Being unaffected by astroglial and/or microglial energy demands, changes in synaptic density in the MTL may therefore be more sensitive to early detection of pathological conditions compared to changes in glucose metabolism.

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