Impact of acute and subchronic inhalation exposure to PbO nanoparticles on mice.

Lead nanoparticles (NPs) are released into air from metal processing, road transport or combustion processes. Inhalation exposure is therefore very likely to occur. However, even though the effects of bulk lead are well known, there is limited knowledge regarding impact of Pb NPs inhalation. This study focused on acute and subchronic exposures to lead oxide nanoparticles (PbO NPs). Mice were exposed to PbO NPs in whole body inhalation chambers for 4-72 h in acute experiment (4.05 × 106 PbO NPs/cm3), and for 1-11 weeks in subchronic experiment (3.83 × 105 particles/cm3 in lower and 1.93 × 106 particles/cm3 in higher exposure group). Presence of NPs was confirmed in all studied organs, including brain, which is very important considering lead neurotoxicity. Lead concentration gradually increased in all tissues depending on the exposure concentration and duration. The most burdened organs were lung and kidney, however liver and brain also showed significant increase of lead concentration during exposure. Histological analysis documented numerous morphological alterations and tissue damage, mainly in lung, but also in liver. Mild pathological changes were observed also in kidney and brain. Levels of glutathione (reduced and oxidized) were modulated mainly in lung in both, acute and subchronic exposures. Increase of lipid peroxidation was observed in kidney after acute exposure. This study characterized impacts of short to longer-term inhalation exposure, proved transport of PbO NPs to secondary organs, documented time and concentration dependent gradual increase of Pb concentration and histopathological damage in tissues.

Sub-chronic inhalation of lead oxide nanoparticles revealed their broad distribution and tissue-specific subcellular localization in target organs.

BACKGROUND: Lead is well known environmental pollutant, which can cause toxic effects in multiple organ systems. However, the influence of lead oxide nanoparticles, frequently emitted to the environment by high temperature technological processes, is still concealed. Therefore, we investigate lead oxide nanoparticle distribution through the body upon their entry into lungs and determine the microscopic and ultramicroscopic changes caused by the nanoparticles in primary and secondary target organs. METHODS: Adult female mice (ICR strain) were continuously exposed to lead oxide nanoparticles (PbO-NPs) with an average concentration approximately 106 particles/cm3 for 6 weeks (24 h/day, 7 days/week). At the end of the exposure period, lung, brain, liver, kidney, spleen, and blood were collected for chemical, histological, immunohistochemical and electron microscopic analyses. RESULTS: Lead content was found to be the highest in the kidney and lungs, followed by the liver and spleen; the smallest content of lead was found in brain. Nanoparticles were located in all analysed tissues and their highest number was found in the lung and liver. Kidney, spleen and brain contained lower number of nanoparticles, being about the same in all three organs. Lungs of animals exposed to lead oxide nanoparticles exhibited hyperaemia, small areas of atelectasis, alveolar emphysema, focal acute catarrhal bronchiolitis and also haemostasis with presence of siderophages in some animals. Nanoparticles were located in phagosomes or formed clusters within cytoplasmic vesicles. In the liver, lead oxide nanoparticle exposure caused hepatic remodeling with enlargement and hydropic degeneration of hepatocytes, centrilobular hypertrophy of hepatocytes with karyomegaly, areas of hepatic necrosis, occasional periportal inflammation, and extensive accumulation of lipid droplets. Nanoparticles were accumulated within mitochondria and peroxisomes forming aggregates enveloped by an electron-dense mitochondrial matrix. Only in some kidney samples, we observed areas of inflammatory infiltrates around renal corpuscles, tubules or vessels in the cortex. Lead oxide nanoparticles were dispersed in the cytoplasm, but not within cell organelles. There were no significant morphological changes in the spleen as a secondary target organ. Thus, pathological changes correlated with the amount of nanoparticles found in cells rather than with the concentration of lead in a given organ. CONCLUSIONS: Sub-chronic exposure to lead oxide nanoparticles has profound negative effects at both cellular and tissue levels. Notably, the fate and arrangement of lead oxide nanoparticles were dependent on the type of organs.

Impact of acute and chronic inhalation exposure to CdO nanoparticles on mice.

Cadmium nanoparticles can represent a risk in both industrial and environmental settings, but there is little knowledge on the impacts of their inhalation, especially concerning longer-term exposures. In this study, mice were exposed to cadmium oxide (CdO) nanoparticles in whole body inhalation chambers for 4 to 72 h in acute and 1 to 13 weeks (24 h/day, 7 days/week) in chronic exposure to investigate the dynamics of nanoparticle uptake and effects. In the acute experiment, mice were exposed to 2.95 × 106 particles/cm3 (31.7 µg CdO/m3). The same concentration and a lower one (1.18 × 106 particles/cm3, 12.7 µg CdO/m3) were used for the chronic exposure. Transmission electron microscopy documented distribution of nanoparticles into all studied organs. Major portion of nanoparticles was retained in the lung, but longer exposure led to a greater relative redistribution into secondary organs, namely the kidney, and also the liver and spleen. Accumulation of Cd in the lung and liver occurred already after 24 h and in the brain, kidney, and spleen after 72 h of exposure, and a further increase of Cd levels was observed throughout the chronic exposure. There were significant differences in both Cd accumulation and effects between the two exposure doses. Lung weight in the higher exposure group increased up to 2-fold compared to the control. Histological analyses showed dose-dependent alterations in lung and liver morphology and damage to their tissue. Modulation of oxidative stress parameters including glutathione levels and increased lipid peroxidation occurred mainly after the greater chronic exposure. The results emphasize risk of longer-term inhalation of cadmium nanoparticles, since adverse effects occurring after shorter exposures gradually progressed with a longer exposure duration.

Combined surgical and endovascular treatment of extensive thoracic aortic aneurysm.

AIM: Patients with extensive aneurysm involving ascending aorta, aortic arch and descending aorta are usually treated by sequential operations. For these patients we can also use combined surgical and endovascular treatment. The experience with this procedure published in the literature is very limited. We report our experience in the ''elephant trunk'' technique followed by an endovascular stent-grafting of the descending thoracic aorta in a small group of three consecutive patients with extensive thoracic aortic aneurysm. METHODS: Three consecutive patients with extensive thoracic aortic aneurysm or chronic dissection underwent combined surgical and endovascular treatment between January and December 2004. The procedure was carried out as a two-stage procedure. During the first stage aortic arch was replaced using the elephant-trunk'' method and during the second stage the stentgrafting of the descending aorta was performed. RESULTS: All three patients were treated successfully. There was no death, no endoleak and no permanent neurological deficit. One patient had a transient paraparesis. In all patients the spiral CT demonstrated excellent technical result without endoleak and with thrombosis of the paraprosthetic space. CONCLUSIONS: We can conclude, that the combined surgical and endovascular treatment of extensive thoracic aortic aneurysm is a feasible method which could reduce mortality and morbidity. In our institution the elephant trunk technique followed by an endovascular stent-grafting of the descending aorta is the preferred method of treatment in patients with extensive thoracic aortic aneurysm involving ascending aorta, aortic arch and descending aorta.

[Options for combining surgical and endovascular techniques in the management of large aneurysms and dissections of the thoracic aorta]. / Moznosti pouzití kombinace chirurgických a endovaskulárních technik v lécbe rozsáhlých aneuryzmat a disekcí hrudní aorty.

The surgical management of aneurysms and dissections of the thoracic aorta, as well as their endovascular management, all have their technical and medical limits. The aim of this work is to point out possibility for combination of the both treatment methods and to share our first practical experience with this procedure. The procedures conducted have been divided into the following groups: combined procedures, where the surgical part enables implantation of the stentgraft into the descending aorta or is managing imperfect results of such implantations, procedures, where combining the surgical and endovascular treatment lowers operational stress of the patient, as the extracorporeal circulation and the circulation arrest are not required, procedures, where advantages of both the surgical treatment in the region of the aortic arch and the endovascular treatment in the region of the descending aorta, are combined. Using the combination of both the surgical and endovascular techniques in the management of the large aneurysms and dissections of the thoracic aorta, appears to be a perspective method. The patient may benefit from its lower perioperative risk rates and lower postoperative morbidity rates. A good long-term effect of the above treatment method may be expected, however, it has to be verified in long-term patient studies.

[Reconstruction of the femoro-popliteal and peripheral portion in saphenous insufficiency]. / Náhradní rekonstrukce femoropopliteálního a periferního úseku pri nedostatku safény.

Implantation of a venous bypass is the best method of infraarticular and crural reconstructions. In 30%, however, a suitable saphenous vein is not available. If on account of severe ischemia revascularization is necessary, an alternative method must be selected. From a total number of 326 peripheral reconstructions with a distal anastomosis into the distal popliteal artery or crural artery the authors had to use instead of a long venous bypass a subsidiary reconstruction in 145 patients (44.6%). The authors implanted composite venous bypasses in 36 patients (24%), in 93 patients (64%) they combined a venous bypass with desobliteration of the superficial femoral artery and in 16 patients (11%) with an artificial prosthesis. For the end-to-end anastomosis of the prosthesis and vein the authors suggested a plastic operation by means of a venous patch which makes a short anastomosis possible with a smooth transit from a wide prosthesis into a narrow vein. The authors assume that in future ever more frequently the combination prosthesis and vein in the shape of a jump bypass will be preferred to other reconstructive methods, as it is relatively simple and rapid. Their hitherto assembled experience with this methods is favourable.

[Surgical treatment of post-traumatic thrombosis of the inferior vena cava]. / Chirurgická lécba poúrazové trombózy dolní duté zíly.

A 49-year-old man contracted a fracture of the 8th and 9th rib on the right side and developed after this injury thrombosis of the inferior vena cava in the renal and suprarenal portion and of both renal veins manifested clinically as nephrotic syndrome of obscure aetiology. Only detailed cavographic and CT examination revealed this thrombosis. Caval thrombectomy was performed according to Spencer's method because of concurrent phlebothrombosis of the left lower extremity. The patient is in a satisfactory condition with permanent Pelentan medication.

[Chemical lumbar sympathectomy]. / Chemická bederní sympatektomie.

After an account of historical facts the authors describe the technique of chemical lumbar sympathectomy. A 7.5% phenol solution in glycerol was used (7.5 ml). At the Surgical Clinic of the Institute for Postgraduate Medical Training of the Regional Hospital with Policlinic in Ostrava chemical lumbar sympathectomy was performed in 22 patients. No complications were observed during operation and during the postoperative period and in all patients the effect was favourable.

[Arteriovenous shunt--a prerequisite for long-term hemodialysis therapy]. / Arteriovenózní shunt--nezbytná podmínka dlouhodobého hemodialyzacního lécení.

The authors give an account of the experience of their department with the establishment of arteriovenous fistulae during the preparation of patients for a dialyzation transplantation programme. In the course of 13 years a total of 685 a-v shunts were made. The results in 60 patients are evaluated in detail. These patients were treated in 1989 in the chronic dialyzation programme of the Ostrava dialyzation unit, focused on long-term patency of the fistulae. The cumulative patency of shunts up to one year is 83.3%, the long-term patency is 73.3%.

[Personal experience with the use of acute isovolemic hemodilution in vascular surgery]. / Nase zkusenosti s uzitím akutní izovolemické hemodiluce v cévní chirurgii.

The authors present their eight-year experience with acute isovolaemic haemodilution during operations on blood vessels in the aorto-femoro-popliteal region. They remind of basic physiological findings, present actual results, and based on their experience and data in the literature, they formulate the main principles of indications and implementation of haemodilution.

Significance of pedal arch for femoropopliteal vein bypass patency.

There are different opinions about the usefulness of preoperative arteriography. Therefore we resolved to show its importance for the distal runoff evaluation as well as for the indication and results of femoropopliteal vein bypasses. There were controlled 149 patients 1-5 years after femoropopliteal vein bypass implantations. Seventy six vein bypasses proved to be patent and seventy three were closed. The findings of preoperative arteriographies visualizating the whole arterial periphery, including the pedal arch arteries, were compared in both groups of patients. It was proved that the evaluation of the distal runoff by means of preoperative arteriography may be reliable and correct under condition of tibial and pedal arch arteries visualization. According to our experience, the preoperative arteriography can be performed in such a way to fulfil this indispensable condition. In rare case of preoperative arteriography repeated failure, it is the peroperative prebypass arteriography, which always is successful. In evaluating the distal runoff, there must be taken into consideration the whole arterial complex: tibial + pedal arch arteries. The patency of pedal arch seems to be more important than the number of patent tibial arteries. According to preoperative arteriographic findings, there is possible to distinguish three main types of distal runoff: (1) Sufficient runoff: whole pedal arch and 1-3 tibial arteries patent; (2) satisfactory runoff: partial pedal arch patency and 1-3 tibial arteries patent; (3) Unsufficient runoff: total pedal arch obliterations and 1-3 tibial arteries patency.

[Significance of the pedal arch for patency of femoropopliteal bypasses]. / Význam pedálního oblouku pro pruchodnost femoropopliteálních bypassu.

The authors pay attention to the evaluation of drainage in indications of femoropopliteal reconstructions with regard to the patency of the peripheral circulation. Based on comparison of preoperative arteriographic findings regarding the patency of venous femoropopliteal bypasses in 149 operated patients the authors were able to confirm their previous assumption that when evaluating the drainage it is necessary to take into consideration not only the number of patent arteries on the leg but also the patency of their continuation in the area of the sole where they form the plantar arch. When evaluating the drainage it is thus necessary to evaluate the patency of the entire complex: arteries of the leg+plantar arch. From this ensues the authors' demand to use in indications of femoropopliteal reconstructions as a basis arteriography which visualizes the entire peripheral arterial circulation incl. the plantar arch.