[Surgical prevention of progressive cerebral ischemia after ischemic stroke]

OBJECTIVE

To evaluate the effectiveness of carotid endarterectomy after ischemic stroke and to analyze postoperative neurological status.

MATERIAL AND METHODS

There were 120 patients with carotid artery stenosis complicated by chronic cerebrovascular insufficiency (CVI). Patients with CVI grade I-III were included in the first group (n=70), 50 patients had previous ischemic stroke (the second group). Age of patients was 61-89 years. All patients underwent unilateral carotid endarterectomy.

RESULTS

Over 36-month follow-up period, postoperative stroke occurred in 5 (7.2%) and 9 (18.3%) patients in both groups, respectively. The combined end-point (stroke + mortality) was significantly less common in group I compared to group II (10 (14.5%) and 15 (30%) cases, p>0.05). Positive changes in neurological status were found in the 2^nd group (relief of focal neurological deficit, symptoms of cerebrovascular insufficiency, no progression of vascular dementia). Barthel score increased from 74.3 to 92.8 after carotid endarterectomy in the 2^nd group. Baseline FAB score <11 was observed in 9% of patients in the 1^st group and 22% in the 2^nd group. No progression of dementia was observed in long-term period.

CONCLUSION

Carotid endarterectomy is effective in prevention of primary and recurrent stroke. Moreover, this procedure slows down progression of chronic cerebral ischemia and cognitive impairment.

[Carotid endarterectomy and stenting in patients with internal carotid artery stenosis and contralateral occlusion]

AIM

To determine surgical risk factors and to compare early outcomes after carotid endarterectomy and carotid stenting in patients with internal carotid artery stenosis and contralateral occlusion.

MATERIAL AND METHODS

132 patients were enrolled. 62 and 70 patients underwent carotid endarterectomy and carotid stenting respectively. Early postoperative results were compared depending on type of surgical intervention and presence of risk factors.

RESULTS

Significant difference between groups was only found for incidence of neuropathy of the cranial nerves. It was established that cardiac comorbidities are risk factors for adverse events after carotid endarterectomy. Stable (homogeneous) atherosclerotic plaque with clear contour and no ulceration is optimal for carotid stenting.

[Hybrid reconstructions in patients with lower limb chronic ischaemia and multilevel arterial lesions]

Presented herein is a review of the literature related to performing hybrid operations for multilevel lesions of the arteries of the lower limbs. This is accompanied and followed by analysing the data on variants of stagewise use of different methods of revascularization in hybrid interventions ("open" and endovascular) on the lower extremities, as well as complications, lethality rates, and remote results as compared with the parallel parameters obtained while performing non-hybrid operations.

A Method for Microencapsulation of Cells and a Device for Its Realization

The device for cell encapsulation makes it possible to fabricate microcapsules of a preset size with even smooth surface, without defects or adhesion to each other, with viable cells inside the capsule. The cells were derived from newborn piglet pancreases.

[Treatment of patients with critical lower limb ischaemia: endovascular methods or reconstructive operations]

Presented herein is a review of the literature related to endovascular methods of treatment of patients with critical lower limb ischaemia. This is followed by comparative assessment of the outcomes of endovascular and open surgical interventions. Also covered are problems concerning appropriate therapeutic decision making, taking into consideration peculiarities of lower limb ischaemia and the state at the expense of insufficiency of inflow/outflow.

[Secondary reconstructions after endovascular treatment of a woman with critical lower limb ischaemia]

Primary endovascular interventions carried out according to the indications determined by the TASC II guidelines have proved successful in treatment of patients presenting with critical lower limb ischaemia. However, performing secondary and complicated reconstructions requires an individual approach with the assessment of all possible risks involved. Presented herein is a clinical case report regarding repeat reconstruction in a woman with critical lower limb ischaemia after a previously performed endovascular intervention.

Discovery of an essential nucleotidylating activity associated with a newly delineated conserved domain in the RNA polymerase-containing protein of all nidoviruses

RNA viruses encode an RNA-dependent RNA polymerase (RdRp) that catalyzes the synthesis of their RNA(s). In the case of positive-stranded RNA viruses belonging to the order Nidovirales, the RdRp resides in a replicase subunit that is unusually large. Bioinformatics analysis of this non-structural protein has now revealed a nidoviral signature domain (genetic marker) that is N-terminally adjacent to the RdRp and has no apparent homologs elsewhere. Based on its conservation profile, this domain is proposed to have nucleotidylation activity. We used recombinant non-structural protein 9 of the arterivirus equine arteritis virus (EAV) and different biochemical assays, including irreversible labeling with a GTP analog followed by a proteomics analysis, to demonstrate the manganese-dependent covalent binding of guanosine and uridine phosphates to a lysine/histidine residue. Most likely this was the invariant lysine of the newly identified domain, named nidovirus RdRp-associated nucleotidyltransferase (NiRAN), whose substitution with alanine severely diminished the described binding. Furthermore, this mutation crippled EAV and prevented the replication of severe acute respiratory syndrome coronavirus (SARS-CoV) in cell culture, indicating that NiRAN is essential for nidoviruses. Potential functions supported by NiRAN may include nucleic acid ligation, mRNA capping and protein-primed RNA synthesis, possibilities that remain to be explored in future studies.

Interspecific adaptation by binary choice at de novo polyomavirus T antigen site through accelerated codon-constrained Val-Ala toggling within an intrinsically disordered region

It is common knowledge that conserved residues evolve slowly. We challenge generality of this central tenet of molecular biology by describing the fast evolution of a conserved nucleotide position that is located in the overlap of two open reading frames (ORFs) of polyomaviruses. The de novo ORF is expressed through either the ALTO protein or the Middle T antigen (MT/ALTO), while the ancestral ORF encodes the N-terminal domain of helicase-containing Large T (LT) antigen. In the latter domain the conserved Cys codon of the LXCXE pRB-binding motif constrains codon evolution in the overlapping MT/ALTO ORF to a binary choice between Val and Ala codons, termed here as codon-constrained Val-Ala (COCO-VA) toggling. We found the rate of COCO-VA toggling to approach the speciation rate and to be significantly accelerated compared to the baseline rate of chance substitution in a large monophyletic lineage including all viruses encoding MT/ALTO and three others. Importantly, the COCO-VA site is located in a short linear motif (SLiM) of an intrinsically disordered region, a typical characteristic of adaptive responders. These findings provide evidence that the COCO-VA toggling is under positive selection in many polyomaviruses, implying its critical role in interspecific adaptation, which is unprecedented for conserved residues.

[Outcomes of carotid endarterectomy and stenting in patients with carotid artery stenosis]

Analysed in the article are the outcomes of treating a total of 156 patients diagnosed with carotid artery stenosis. Of these, carotid endarterectomy was performed in 82 patients and stenting of carotid arteries was carried out in the remaining 74 patients. The incidence rate of perioperative stroke in the carotid endarterectomy group amounted to 3.6%, being in the stenting group 4.8%, P = 0.57. Multifactorial analysis was used to reveal risk factors for each method. Thus, in the carotid endarterectomy group, the risk factors for cerebrovascular complications appeared to be contralateral occlusion in patients with a history of stroke endured within less than six previous months (P<0.05), as well as the age over 75 years amongst the patients requiring placement of a temporary intraluminal bypass graft (P<0.05). For carotid stenting, risk factors of cerebrovascular complications included a hypoechogenic heterogeneous type of an atherosclerotic plaque (P<0.05) and ulceration of its surface (P<0.05). The presence of the patient's baseline functional class III angina of effort appeared to be a risk factor for the development of cardiovascular complications for carotid endarterectomy (P<0.05). No cardiovascular risk factors for carotid stenting were revealed. Based on the assessment of the risk factors thus detected, the authors worked out an algorithm of choosing an optimal treatment policy for patients presenting with carotid artery stenosis.

Design and validation of consensus-degenerate hybrid oligonucleotide primers for broad and sensitive detection of corona- and toroviruses

The ssRNA+ family Coronaviridae includes two subfamilies prototyped by coronaviruses and toroviruses that cause respiratory and enteric infections. To facilitate the identification of new distantly related members of the family Coronaviridae, we have developed a molecular assay with broad specificity. The consensus-degenerated hybrid oligonucleotide primer (CODEHOP) strategy was modified to design primers targeting the most conserved motifs in the RNA-dependent RNA polymerase locus. They were evaluated initially on RNA templates from virus-infected cells using a two-step RT-PCR protocol that was further advanced to a one-step assay. The sensitivity of the assay ranged from 10² to 10⁶ and from 10⁵ to 10⁹ RNA copy numbers for individual corona-/torovirus templates when tested, respectively, with and without an excess of RNA from human cells. This primer set compared to that designed according to the original CODEHOP rules showed 10–10³ folds greater sensitivity for 5 of the 6 evaluated corona-/torovirus templates. It detected 57% (32 of 56) of the respiratory specimens positive for 4 human coronaviruses, as well as stool specimens positive for a bovine torovirus. The high sensitivity and broad virus range of this assay makes it suitable for screening biological specimens in search for new viruses of the family Coronaviridae.

Practical application of bioinformatics by the multidisciplinary VIZIER consortium

This review focuses on bioinformatics technologies employed by the EU-sponsored multidisciplinary VIZIER consortium (Comparative Structural Genomics of Viral Enzymes Involved in Replication, FP6 PROJECT: 2004-511960, active from 1 November 2004 to 30 April 2009), to achieve its goals. From the management of the information flow of the project, to bioinformatics-mediated selection of RNA viruses and prediction of protein targets, to the analysis of 3D protein structures and antiviral compounds, these technologies provided a communication framework and integrated solutions for steady and timely advancement of the project. RNA viruses form a large class of major pathogens that affect humans and domestic animals. Such RNA viruses as HIV, Influenza virus and Hepatitis C virus are of prime medical concern today, but the identities of viruses that will threaten human population tomorrow are far from certain. To contain outbreaks of common or newly emerging infections, prototype drugs against viruses representing the Virus Universe must be developed. This concept was championed by the VIZIER project which brought together experts in diverse fields to produce a concerted and sustained effort for identifying and validating targets for antivirus therapy in dozens of RNA virus lineages.

[Neurological status and quality of life in patients with degree IV chronic cerebral ischaemia after endured carotid endarterectomy]

The study was aimed at evaluating the dynamics of the neurological status and quality of life (QOL) in patients after endured carotid endarterectomy (CEA) with previously sustained ischaemic stroke (IS).

MATERIALS AND METHODS

At the Department of Vascular Surgery of the B. V. Petrovsky Russian Research Centre of Surgery under the Russian Academy of Medical Sciences, from 2001 to 2009 we treated a total of ninety-six patients after endured IS. CEA was performed in fifty-one patients (Group I), and the control group patients underwent conservative treatment (Group II). QOL was assessed by means of the Medical Outcomes Study Short Form - 36 (SF-36) questionnaire and the Bartel scale (predominantly in order to determine life activity). Initially, patients from the both groups had had equally low baseline QOL scores. After one year we carried out a repeat survey using the same SF-36, Bartel scale, and examination by the neurologist. Relapses of cerebral circulatory impairments were registered in two (3.9%) Group I patients and in three (6.6%) Group II subjects (p>0.05). Total mortality rate in Group I amounted to 1 (1.9%) case and in Group II - 2 (4.4%) lethal cases (p>0.05). According to the findings of the SF-36 questionnaire, restoration of the lostfunctions was observed in eleven (22%) Group I patients and in five (11.6%) Group II patients. Partial restoration was seen in seventeen (34%) Group I patients and in twelve (27.9%) Group H subjects. The neurological status was noted to have preserved in twenty- three (46%) Group I patients and in twenty-six (60.5%) Group II patients (p>0.05). Both in Group I and Group II patients, positive dynamics of the neurological status was observed among those being in the early restoration period (p<0.05).

CONCLUSION

CEA performed in the early restoration period in patients with endured IS appeared to promote improved neurological status, extending physical activity, improving QOL, and is thus an efficient means of preventing relapses of cerebrovascular circulatory impairments.

[Surgical treatment of an aneurysm of the superficial femoral artery 40 years after an injury: a case report]

Presented herein is a case report of a male patient with a posttraumatic aneurysm revealed 40 years after an injury. The presence of a foreign body in the lumen of the artery for such a long time had had no manifestations and was detected by ultrasonographic duplex scanning. The patient was subjected to resection of the aneurysm of the superficial femoral artery on the right lower limb with prosthetic repair performed by a reversed autovein.

[Preventive maintenance of repeated ischemic insults]

In the review we offer analysis of the effectiveness of carotid endarterectomy in treatment of post-functional apoplexy or stroke patients. Published results of the researches specify possible efficiency of carotid endarterectomy in preventive maintenance against repeated apoplectic attack or strokes. Yet the criteria of usage and execution of the carotid endarterectomy are still to be discussed.