Andrzej Loesch

University College London | UCL · Division of Medicine, Royal Free Campus, Research Department of Inflammation, Centre for Rheumatology and Connective Tissue Diseases

Vascular endothelium and perivascular nerve fibres of the autonomic nervous system regulate the diameter of blood vessels, and hence blood pressure and flow, by releasing vasoactive agents acting on smooth muscle cells in the vessel wall resulting in their relaxation or constriction. The distribution of vasoactive agents and nitric oxide synthase i...

There is introductory information about non-synaptic transmission at sympathetic neuroeffector junctions and sympathetic nerve cotransmission utilizing noradrenaline and ATP as cotransmitters. Then the organzation and location of sympathetic nerves in different sites in the kidney are described, including renal arteries, juxtaglomerular arterioles...

Perivascular fat, the cushion of adipose tissue surrounding blood vessels, possesses dilator, anti-contractile and constrictor actions. The majority of these effects have been demonstrated in vitro and may depend on the vessel and/or the experimental method or species used. In general, the relaxant effect of perivascular adipose tissue is local and...

The saphenous vein (SV) is the most commonly used conduit for revascularization in patients undergoing coronary artery bypass surgery (CABG). The patency rate of this vessel is inferior to the internal thoracic artery (ITA). In the majority of CABG procedures the ITA is removed with its outer pedicle intact whereas the (human) SV (hSV) is harvested...

This tribute article presents selected immunocytochemical and transmission electron microscope data on the location of ATP-gated P2X receptor in the rat brain, as studied in the 1990s in Prof G. Burnstock’s laboratory at University College London. There are examples of immuno-ultrastructural findings and introductory information about pre- and post...

This short article discusses selected scanning electron microscope and transmission electron microscope features of vasa vasorum including pericytes and basement membrane of the human saphenous vein (SV) harvested with either conventional (CON) or no-touch (NT) technique for coronary artery bypass grafting. Scanning electron microscope data shows t...

Saphenous veins used for coronary artery bypass surgery are subjected to considerable vascular trauma when harvested by conventional methods. This vascular damage is responsible, at least in part, for the inferior patency of the saphenous vein when compared with the internal thoracic artery. The performance of saphenous vein grafts is improved when...

The importance of the vasa vasorum and blood supply to the wall of human saphenous vein (hSV) used for coronary artery bypass grafting (CABG) is briefly discussed. This is in the context of the possible physical link of the vasa vasorum connecting with the lumen of hSV and the anti-ischaemic impact of this microvessel network in the hSV used for CA...

It has been reported that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection induces endothelial inflammation, therefore facilitating the progression of endothelial and vascular dysfunction in coronavirus disease 2019 (COVID-19) patients. Coronary artery bypass grafting (CABG) involves mainly the use of the saphenous vein (SV) a...

The saphenous vein is the most commonly used bypass graft in patients with coronary artery disease. During routine coronary artery bypass, grafting the vascular damage inflicted on the vein is likely to stimulate the release of endothelin-1, a potent endothelium-derived vasoconstrictor that also possesses cell proliferation and inflammatory propert...

Perivascular adipose tissue (PVAT) is a source of factors affecting vasomotor tone with the potential to play a role in the performance of saphenous vein (SV) bypass grafts. As these factors have been described as having constrictor or relaxant effects, they may be considered either beneficial or detrimental. The close proximity of PVAT to the adve...

The saphenous vein is the most commonly used bypass graft in patients with coronary artery disease. During routine coronary artery bypass grafting the vascular damage inflicted on the vein is likely to stimulate the release of endothelin-1, a potent endothelium-derived vasoconstrictor that also possesses cell proliferation and inflammatory properti...

The saphenous vein (SV) is the most commonly used conduit for coronary artery bypass surgery (CABG) and the second conduit of choice in Brazil and many other countries. The radial artery (RA) is suggested, by some, to be superior to SV grafts, although its use in the USA declined over a 10 year period. The patency of SV grafts (SVG) is improved whe...

The saphenous vein (SV) is the most commonly used conduit for revascularization in patients undergoing coronary artery bypass surgery (CABG). The patency rate of this vessel is inferior to the internal thoracic artery (ITA). In the majority of CABG procedures the ITA is removed with its outer pedicle intact whereas the (human) SV (hSV) is harvested...

The saphenous vein (SV) is the most commonly used conduit for revascularization in patients undergoing coronary artery bypass surgery (CABG). The patency rate of this vessel is inferior to the internal thoracic artery (ITA). In the majority of CABG procedures the ITA is removed with its outer pedicle intact whereas the (human) SV (hSV) is harvested...

Letter to the Editor. Title Page Pedicled Vein Grafts in Coronary Operation: No-Touch Harvesting Under Pressure. Andrzej Loesch 1 and Michael R Dashwood 2, Centre for Rheumatology 1 and Surgical and Interventional Sciences 2, Royal Free Hospital Campus, University College Medical School, London, United Kingdom. Running Head: Why Distend Pedicled Ve...

Perivascular fat, the cushion of adipose tissue surrounding blood vessels, possesses dilator, anti-contractile and constrictor actions. The majority of these effects have been demonstrated in vitro and may depend on the vessel and/or the experimental method or species used. In general, the relaxant effect of perivascular adipose tissue is local and...

Objective: The aim of the present study was to investigate the putative effects of a low-protein diet on the three-dimensional structure of hepatocytes and determine whether this scenario could be reversed by restoring the adequate levels of protein to the diet. Methods: Using design-based stereology, the total number and volume of hepatocytes we...

In the context of the recently published fascinating study of brain function and vascular abnormalities in Alzheimer's disease by Iturria-Medina and colleagues [1], the current editorial discusses the possibility of contribution of autonomic cerebrovascular nerves to cerebral disease.

Multinucleated giant cells (MGCs) form by fusion of macrophages and are presumed to contribute to the removal of debris from tissues. In a systematic in vitro analysis, we show that IL-4-induced MGCs phagocytosed large and complement-opsonized materials more effectively than their unfused M2 macrophage precursors. MGC expression of complement recep...

MGCs and macrophages were incubated with 45 μm latex beads for 24 hrs. 3D visualization of z-stack confocal images used for Figure S1A (red: external beads; grey: cellular membrane). Movie was created using volume rendering of Imaris software with 24 frames per second display rate.

MGCs and macrophages were incubated with 45 μm latex beads for 24 hrs. 3D visualization of z-stack confocal images used for Figure S1B (grey: cellular membrane). Movie was created using volume rendering of Imaris software with 24 frames per second display rate.

Movie S3. MGC Membrane Ruffles Visualized by Confocal Microscopy, Related to Figure 6 Consecutive images of z-stack shown as merged image in Figure 6D (lower panel). Movie was created using ImageJ software with 10 frames per second display rate.

3D visualization of MGC membrane ruffles as shown in Figure 6G. 3D projection was created using surface rendering of Imaris software with 24 frames per second display rate.

Coronary artery disease is the major cause of mortalilty in the West with coronary artery bypass surgery (CABG) being a means of restoring blood supply to ischaemic myocardium. The long saphenous vein is the most commonly used bypass conduit but its patency is inferior to the internal thoracic artery, the �gold standard� graft. In conventional proc...

The purpose of this qualitative morphological study was the immunocytochemical and ultrastructural comparison of perivascular nerves of the basilar artery (BA) of young (6-month-old) and adult (12-month-old) capybaras - adult capybaras showed regression of the internal carotid artery (ICA). The study focused on immunolabeling for the vasoactive pep...

No-touch (NT) saphenous vein (SV) grafts are superior to SVs harvested by the conventional technique (CT), with a patency comparable with the internal thoracic artery (ITA). Preservation of the vasa vasorum is implicated in the success of NT harvesting. We compared the vasa vasorum and endothelial nitric oxide synthase (eNOS) in NT SV with ITA and...

Erectile dysfunction (ED) commonly occurs in approximately 15% of men over 70 years old. A number of causes of this condition are recognised with the major mechanism of ED being an impaired relaxation of the corpus cavernosum (CC) smooth muscle and resulting reduction in penile blood flow. There are reports that ED is associated with a reduction in...

This is a short overview on synaptic coverage of the dendritic tree in the superior cervical ganglion of capybara based on the application of the electron-immunocytochemistry of synaptophysin combined with stereological tools. It is shown how to estimate the surface coverage of dendrites by postsynaptic apposi-tion zones and how to perform a model-...

The saphenous vein (SV) is the most commonly used conduit for CABG but its patency rate is poor compared with the internal mammary artery (IMA). In conventional harvesting the saphenous vein’s outer layer, the adventitia, is damaged and this affects the perivascular nerves. In addition the cushion of perivascular fat (PVF) surrounding the vein i...

Our objective was to evaluate the impact of vein graft harvesting technique on structure and function of vasa vasorum. Paired segments of great saphenous veins harvested either with conventional harvesting technique or no-touch technique were obtained from 9 consecutive patients undergoing coronary artery bypass grafting. Quantitative measurements,...

Endothelin-1 (ET-1) is an endothelium-derived peptide that also possesses potent mitogenic activity. There is also a suggestion the ET-1 is a neuropeptide, based mainly on its histological identification in both the central and peripheral nervous system in a number of species, including man. A neuropeptide role for ET-1 is supported by studies show...

In diabetes mellitus (DM) reduced motor and sensory properties of peripheral nerves are linked with the dysfunction of neural vasculature. We investigated C-fibers and microvessels of sciatic nerve of normal, DM, and DM + epoetin delta-treated rats. C-fibers immunoreactive for calcitonin gene-related peptide (CGRP), tyrosine hydroxylase (TH), epoet...

Accumulation of amyloid fibrils in the viscera and connective tissues causes systemic amyloidosis, which is responsible for about one in a thousand deaths in developed countries. Localized amyloid can also have serious consequences; for example, cerebral amyloid angiopathy is an important cause of haemorrhagic stroke. The clinical presentations of...

The superior cervical ganglion (SCG) in mammals varies in structure according to developmental age, body size, gender, lateral asymmetry, the size and nuclear content of neurons and the complexity and synaptic coverage of their dendritic trees. In small and medium-sized mammals, neuron number and size increase from birth to adulthood and, in phylog...

This contribution is a selective mini-overview of changes in the peripheral nerve and cerebral vasculature in diabetes. New data is also included that shows the effect of epoetin on diabetic rat sciatic nerve and basilar artery. In particular, the distribution of endothelial nitric oxide synthase (eNOS) in cerebrovascular endothelium as well as cal...

The renal proximal tubule (PT) is clinically vulnerable to mitochondrial dysfunction; sub-lethal injury can lead to the Fanconi syndrome, with elevated urinary excretion of low-molecular-weight proteins. As the mechanism that couples mitochondrial dysfunction to impaired PT low-molecular weight protein uptake is unknown, we investigated the effect...

We have lately shown that administration of antibodies to serum amyloid P component (SAP) opsonises amyloid and triggers its elimination by a complement and macrophage dependent mechanism. SAP is a normal plasma protein that is specifically concentrated in all amyloid deposits by its avid, reversible, binding to all known amyloid fibrils. This nove...

The saphenous vein (SV), a blood vessel superficially located in the leg, is the most commonly used graft in patients requiring coronary artery bypass surgery (CABG). Using conventional surgical methods of preparing the SV this vessel is subjected to considerable trauma that influences graft performance. While much interest has focussed on reducing...

In a long-term randomised coronary artery bypass grafting (CABG) study, the patency rate using a new 'no touch' (NT) vein-graft preparation technique was superior to the conventional (C) technique. This cineangiographic and intravascular ultrasound (IVUS) substudy examined possible mechanisms. A total of 45 patients (118 grafts) in the NT group and...

Erythropoiesis-stimulating agents (ESAs) are used to treat anemia associated with renal failure. It is now known that these agents also show a broad range of cell- and tissue-protective effects. In the current study, we explored whether an ESA, epoetin delta, affects vascular pathology linked to diabetes mellitus (DM). In a rat model of streptozoto...

There are reports of sympathetic innervation of the nephron and of P2 purinergic receptors on epithelial cells. Since ATP is a cotransmitter with noradrenaline in sympathetic nerves, the objective of the present study was to re-investigate basolateral innervation of rat renal collecting duct epithelial cells by sympathetic nerves in the context of...

Phosphoinositide (PI) lipids are intracellular membrane signaling intermediates and effectors produced by localized PI kinase and phosphatase activities. Although many signaling roles of PI kinases have been identified in cultured cell lines, transgenic animal studies have produced unexpected insight into the in vivo functions of specific PI 3- and...

Post-natal development comprises both maturation (from newborn to adult) and ageing (from adult to senility) and, during this phase, several adaptive mechanisms occur in sympathetic ganglia, albeit they are not fully understood. Therefore, the present study aimed at detecting whether post-natal development would exert any effect on the size and num...

Stellate ganglion (SG) represents the main sympathetic input to the heart. This study aimed at investigating physical exercise-related changes in the quantitative aspects of SG neurons in treadmill-exercised Wistar rats. By applying state-of-the-art design-based stereology, the SG volume, total number of SG neurons, mean perikaryal volume of SG neu...

We visualized insulin uptake in vivo across the apical membrane of the rat proximal tubule (PT) by confocal microscopy; we compared it with in vitro findings in a rat PT cell line (WKPT) using fluorescence microscopy and flow cytometry. Surface tubules were observed in vivo with a 633-nm single laser-illuminated real-time video-rate confocal scanni...

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The saphenous vein is the most commonly used conduit in patients undergoing coronary artery bypass surgery. However, a high proportion of vein grafts occlude within the first year and over 50% patients require further grafting within 10 years. Using conventional harvesting techniques the saphenous vein is damaged due to considerable surgical and me...

This review focuses on sympathetic perivascular innervation of human saphenous vein. It shows the distribution of the nerves in the vein wall, including an association of the nerves with the vasa vasorum system. An account of a possible contribution of sympathetic nerves to the physiology of the saphenous vein, as well as their relevance to the out...

This review focuses on sympathetic perivascular innervation of human saphenous vein. It shows the distribution of the nerves in the vein wall, including an association of the nerves with the vasa vasorum system. An account of a possible contribution of sympathetic nerves to the physiology of the saphenous vein, as well as their relevance to the out...

Diabetes mellitus is the most common endocrine disturbance of domestic carnivores and can cause autonomic neurological disorders, although these are still poorly understood in veterinary medicine. There is little information available on the quantitative adaptation mechanisms of the sympathetic ganglia during diabetes mellitus in domestic mammals....

Although the presence of neurotrophin p75 receptor on sympathetic nerves is a well-recognised feature, there is still a scarcity of details of the distribution of the receptor on cerebrovascular nerves. This study examined the distribution of p75 receptor on perivascular sympathetic nerves of the middle cerebral artery and the basilar artery of hea...