Intravascular lithotripsy-assisted percutaneous deep vein arterialization for no-option chronic limb-threatening patients and heavily calcified tibial occlusive disease.

PURPOSE: To report the first chronic limb-threatening ischemia (CLTI) patients who underwent an intravascular lithotripsy (IVL)-assisted percutaneous deep vein arterialization (pDVA). CASE REPORT 1: An 81-year-old patient presented with CLTI and a heavily calcified lesion of the popliteal artery and tibioperoneal trunk (TPT), with a distal tibial and foot arch occlusion. The patient underwent IVL and drug-coated balloon angioplasty for the distal popliteal artery and of the TPT to improve the inflow prior to pDVA. The wound situation remained stable without secondary procedure until the patient`s deaths due to complications of urosepsis 3 months later. CASE REPORT 2: A 64-year-old patient with rest pain of the left limb with a single-vessel tibial run-off (peroneal artery) and occluded pedal arch was treated with 3.5 mm IVL followed by a successful pDVA as mentioned above. IVL performed in the proximal posterior tibial artery to optimize the inflow to the circuit and change the compliance of the crossing point from the arterial to the vein system. The patient underwent repeat angioplasty of the plantar vein arch 5 months after the index procedure and thereafter remained asymptomatic during 2 years of follow-up. CONCLUSION: The combined use of IVL and pDVA could improve the patency of the reconstruction with clinical benefits in no-option CTLI patients.

Polyamines (PAs) but not small peptides with closely spaced positively charged groups interact with DNA and RNA, but they do not represent a relevant buffer system at physiological pH values.

Polyamines (PAs) including putrescine (PUT), spermidine (SPD) and spermine (SPM) are small, versatile molecules with two or more positively charged amino groups. Despite their importance for almost all forms of life, their specific roles in molecular and cellular biology remain partly unknown. The molecular structures of PAs suggest two presumable biological functions: (i) as potential buffer systems and (ii) as interactants with poly-negatively charged molecules like nucleic acids. The present report focuses on the question, whether the molecular structures of PAs are essential for such functions, or whether other simple molecules like small peptides with closely spaced positively charged side chains might be suitable as well. Consequently, we created titration curves for PUT, SPD, and SPM, as well as for oligolysines like tri-, tetra-, and penta-lysine. None of the molecules provided substantial buffering capacity at physiological intracellular pH values. Apparently, the most important mechanism for intracellular pH homeostasis in neurons is not a buffer system but is provided by the actions of the sodium-hydrogen and the bicarbonate-chloride antiporters. In a similar approach we investigated the interaction with DNA by following the extinction at 260 nm when titrating DNA with the above molecules. Again, PUT and tri-lysine were not able to interact with herring sperm DNA, while SPD and SPM were. Obviously, the presence of several positively charged groups on its own is not sufficient for the interaction with nucleic acids. Instead, the precise spacing of these groups is necessary for biological activity.

Autoimmune processes in neurological patients are much more common than presently suspected.

Autoimmune encephalitides are seldom diseases. How rare they actually are, however, is not known. The low incidence combined with the problematic identification may dampen efforts of neurologists, to identify patients with unclear symptoms as suffering from autoimmune encephalitis. Here, we aim to obtain a better estimate, how many patients with autoimmune disorders should be expected among 100 inpatients in a conventional neurological department. From a total number of 2603 non-stroke patients attended in a 2-year period (2018-2019) 460 CSFs were obtained. From this collection 187 samples (40.7%, > 500 sections) could be analyzed with our immunocytochemical technique. Autoreactive antibodies were detected in 102 (55%) of these 187 CSF samples. Certainly, the presence of autoreactive antibodies does not necessarily indicate that the patient suffers from an autoimmune disease. Our data indicate that from roughly 2000 patients during 1 year about 125 patients with autoreactive CSF antibodies should be expected in a conventional neurological department. This represents the about 35-fold value of what is generally expected at present. Being aware of this high incidence may intensify the efforts of neurologist to identify patients with any type of autoimmune encephalitis. This will be beneficial for patients, because they often profit from immunomodulatory therapy. Interestingly, some CFSs from our patients react with the CA2 subdivision of the hippocampus. While long neglected, recent research places this area into an important position to influence hippocampal network physiology. Autoreactive antibodies in the CSF may disturb the function of CA2 neurons, thereby explaining some neuropsychiatric symptoms in patients with autoimmune encephalitides.

As Verified with the Aid of Biotinylated Spermine, the Brain Cannot Take up Polyamines from the Bloodstream Leaving It Solely Dependent on Local Biosynthesis.

The importance of polyamines (PAs) for the central nervous system (CNS) is well known. Less clear, however, is where PAs in the brain are derived from. Principally, there are three possibilities: (i) intake by nutrition, release into the bloodstream, and subsequent uptake from CNS capillaries, (ii) production by parenchymatous organs, such as the liver, and again uptake from CNS capillaries, and (iii) uptake of precursors, such as arginine, from the blood and subsequent local biosynthesis of PAs within the CNS. The present investigation aimed to unequivocally answer the question of whether PAs, especially the higher ones like spermidine (SPD) and spermine (SPM), can or cannot be taken up into the brain from the bloodstream. For this purpose, a biotin-labelled analogue of spermine (B-X-SPM) was synthesized, characterized, and used to visualize its uptake into brain cells following application to acute brain slices, to the intraventricular space, or to the bloodstream. In acute brain slices there is strong uptake of B-X-SPM into protoplasmic and none in fibrous-type astrocytes. It is also taken up by neurons but to a lesser degree. Under in vivo conditions, astrocyte uptake of B-X-SPM from the brain interstitial fluid is also intense after intraventricular application. In contrast, following intracardial injection, there is no uptake from the bloodstream, indicating that the brain is completely dependent on the local synthesis of polyamines.

Unique Chemistry, Intake, and Metabolism of Polyamines in the Central Nervous System (CNS) and Its Body.

Polyamines (PAs) are small, versatile molecules with two or more nitrogen-containing positively charged groups and provide widespread biological functions. Most of these aspects are well known and covered by quite a number of excellent surveys. Here, the present review includes novel aspects and questions: (1) It summarizes the role of most natural and some important synthetic PAs. (2) It depicts PA uptake from nutrition and bacterial production in the intestinal system following loss of PAs via defecation. (3) It highlights the discrepancy between the high concentrations of PAs in the gut lumen and their low concentration in the blood plasma and cerebrospinal fluid, while concentrations in cellular cytoplasm are much higher. (4) The present review provides a novel and complete scheme for the biosynthesis of Pas, including glycine, glutamate, proline and others as PA precursors, and provides a hypothesis that the agmatine pathway may rescue putrescine production when ODC knockout seems to be lethal (solving the apparent contradiction in the literature). (5) It summarizes novel data on PA transport in brain glial cells explaining why these cells but not neurons preferentially accumulate PAs. (6) Finally, it provides a novel and complete scheme for PA interconversion, including hypusine, putreanine, and GABA (unique gliotransmitter) as end-products. Altogether, this review can serve as an updated contribution to understanding the PA mystery.

Accuracy of device landing zone calcium volume measurement with contrast-enhanced multidetector computed tomography.

BACKGROUND: The extent of aortic valve calcification is an important determinant of procedural success in transcatheter aortic valve implantation (TAVI). We sought to validate device landing zone calcium volume (DLZ-CV) measurements on contrast-enhanced multidetector computed tomography (MDCT) with non-contrast-enhanced scans as reference. METHODS: We determined DLZ-CV in 141 patients undergoing transfemoral TAVI. Non-contrast-enhanced images were analyzed using a threshold of 130 HU as reference (DLZ-CV130). For contrast-enhanced scans, we applied various thresholds including 450 HU (DLZ-CV450), 850 HU (DLZ-CV850), mean aortic attenuation (AttenAo) + 2 SD (DLZ-CV2SD), AttenAo + 4 SD (DLZ-CV4SD), AttenAo + 4 SD + 5 mm3 volume filter (DLZ-CV4SD+), and based on visual estimation (DLZ-CVvis). We compared DLZ-CV values between patients with versus without paravalvular leak (PVL), and between patients with versus without post-dilatation stratified by the type of prosthesis. RESULTS: All DLZ-CV measurements on contrast-enhanced scans significantly differed from DLZ-CV130 (p < 0.001 for all comparisons). The best approximation to DLZ-CV130 was achieved with DLZ-CV4SD+ (508 mm3 [332-772]; Pearson correlation: R = 0.87, p < 0.001; Bland-Altman: mean difference 1339 mm3 [limits of agreement 79;2600]). Moreover, DLZ-CV4SD+ allowed for discrimination of PVL ≥1° or the need for post-dilatation in patients receiving self-expanding prostheses. Procedural outcome using balloon-expandable prostheses was independent of DLZ-CV. CONCLUSION: Measurement of DLZ-CV using contrast-enhanced scans with unadjusted thresholds results in incorrect estimation of the calcium volume. The use of a scan-specific individual HU threshold including a volume filter (DLZ-CV4SD+) provides the best approximation to the reference and allows for discrimination of PVL ≥ 1° in patients receiving the Acurate neo prosthesis.