Arterial elasticity measurement in renal transplant recipients

Arterial distensibility is reduced in chronic kidney disease (CKD) and after kidney transplantation. Pulse counter analysis provides an assessment of compliance or elasticity of the large conduit arteries (C1) and small arteries (C2). Decreased compliance has been shown to be predictive of primary coronary events in CKD patients. The aim of the present study was to compare elasticity measurements in hemodialysis (HD) patients, renal transplant recipients (RTR), and healthy subjects whose coronary angiographies were without lesion. Twenty-three RTRs, 18 HD patients, and 20 healthy subjects were included in the study. Pulse wave analysis was used to determine large and small vessel compliances. The C1 and C2 levels were significantly lower in HD patients compared with recipients and healthy subjects. Recipients showed lower C2 level compared with healthy subjects. There was no difference in C1 and C2 measurements between recipients receiving tacrolimus versus cyclosporine. Transplantation improves large and to some extend small artery elasticities in CKD patients.     

End-to-end microvascular anastomosis in the rat carotid artery using continuous horizontal mattress sutures

This paper reports a continuous horizontal mattress suture technique with advantages such as decreased time for anastomosis, minimized anastomotic leakage, eversion around the vessel edges, and other advantages which the continuous anastomosis technique has. This technique was compared with the classical interrupted and classical continuous suture techniques on a total of 59 Sprague-Dawley rat common carotid arteries: Group 1 (n = 19), interrupted suture technique; Group 2 (n = 20), standard continuous technique, and Group 3 (n = 20), continuous horizontal mattress technique. Early (30 min) and late (21 days) patency rates, anastomosis time, leakage on clamp release, oozing duration, additional sutures needed, and total number of sutures placed were statistically compared between groups. Specimens were taken at the 21st day randomly, and light microscopy (LM), scanning electron microscopy (SEM), and angiographic studies were performed. Results revealed that the continuous mattress suture technique has the advantages of providing a water-tight anastomosis with less suture materials in a shorter time, and minimal intraluminal suture material which can incite thrombosis. On the other hand, a tendency to anastomotic stricture was found to be the sole disadvantage of this technique.     

The effect of pentoxifylline on the healing of intestinal anastomosis in rats with experimental obstructive jaundice

The aims of this study were (1) to investigate the effect of experimental obstructive jaundice on the healing of intestinal anastomosis, and (2) to investigate the effect of pentoxifylline on the healing of intestinal anastomosis in rats with obstructive jaundice. Obstructive jaundice was induced in rats by the ligation and division of the common bile duct. Four days after this operation, either pentoxifylline or isotonic saline solution was administered intraperitoneally to these jaundiced rats and controls, and then intestinal anastomosis was performed. The concentrations of serum tumor necrosis factor α (TNF-α) and serum triglyceride of jaundiced and nonjaundiced rats were measured, and the quality of healing was evaluated by measuring the bursting preasure and hydroxyproline content of the anastomoses on the fifth and tenth days of anastomotic healing. Obstructive jaundice resulted in an impaired wound healing of the intestinal anastomosis in the rats. The administration of pentoxifylline to the jaundiced rats resulted in better anastomotic wound healing. The beneficial effects of pentoxifylline on anastomotic healing in rats with obstructive jaundice was attributed to its inhibitor effect on the endotoxin-induced TNF-α release from macrophages and monocytes, and the stabilizing effect on the neutrophils. Received: March 29, 1999 / Accepted: March 24, 2000     

Impairments of Social Interaction in Depressive Disorder

ObjectiveDespite the numerous findings on the altered emotion recognition and dysfunctional social interaction behavior of depressive patients, a lot of the relationships are not clearly clarified.MethodsIn this pilot study, 20 depressive patients (mean±SD, 38.4±14.2) and 20 healthy subjects (mean±SD, 38.9±15.3) (each in dyads) were videographed. We then analyzed their social interaction behavior and emotion processing in terms of emotion recognition, their own emotional experience, and the expression of emotions under the conditions of a semi-structured experimental paradigm. ResultsPatients showed more significant impairment regarding the dimensions of social interaction behavior (i.e., attention, interest, and activity) and their interaction behavior was characterized by neutral affectivity, silence, and avoidance of direct eye contact. This interactive behavioral style was statistically related to depressive psychopathology. There were no differences concerning emotion recognition. ConclusionImpairments of non-verbal and verbal social interaction behavior of depressive patients seem to be less associated with disturbances of basic skills of emotion recognition.     

Self-assembly of the general membrane-remodeling protein PVAP into sevenfold virus-associated pyramids

Viruses have developed a wide range of strategies to escape from the host cells in which they replicate. For egress some archaeal viruses use a pyramidal structure with sevenfold rotational symmetry. Virus-associated pyramids (VAPs) assemble in the host cell membrane from the virus-encoded protein PVAP and open at the end of the infection cycle. We characterize this unusual supramolecular assembly using a combination of genetic, biochemical, and electron microscopic techniques. By whole-cell electron cryotomography, we monitored morphological changes in virus-infected host cells. Subtomogram averaging reveals the VAP structure. By heterologous expression of PVAP in cells from all three domains of life, we demonstrate that the protein integrates indiscriminately into virtually any biological membrane, where it forms sevenfold pyramids. We identify the protein domains essential for VAP formation in PVAP truncation mutants by their ability to remodel the cell membrane. Self-assembly of PVAP into pyramids requires at least two different, in-plane and out-of-plane, protein interactions. Our findings allow us to propose a model describing how PVAP arranges to form sevenfold pyramids and suggest how this small, robust protein may be used as a general membrane-remodeling system.Release of virus particles from infected cells is the last essential step of the viral replication cycle. In the course of this process, virions face the challenging task of crossing the cell envelope. Viruses have developed an arsenal of diverse strategies to overcome this problem. Most bacterial viruses are lytic and induce lysis of the infected cell with help of the holin-endolysin system (1), whereas others disrupt the host cell envelope via inhibition of the murein biosynthesis pathway (2). The morphological and genomic properties of archaeal viruses (3) suggested that their egress from host cells may have unusual traits that are different from those of bacterial viruses. Indeed, although most archaeal viruses exit cells without lysis, some, in particular the Sulfolobus islandicus rod-shaped virus 2 (SIRV2) and Sulfolobus turreted icosahedral virus (STIV), are lytic and exploit a special mechanism of virion egress (4–8). During the infection cycle of these viruses, pyramidal protrusions with sevenfold rotational symmetry form in the host cell membrane. As the final step of the infection cycle the virus-associated pyramids (VAPs) open outwards along the seams of their seven facets, creating ∼100-nm apertures through which the newly formed virions escape from the host cell (4, 7). VAPs consist of multiple copies of an ∼10-kDa virus-encoded protein, which we term “PVAP” (Protein forming Virus-Associated Pyramids/SIRV2_P98) (7–9). Surprisingly, PVAP assembles into membrane pyramids even when expressed heterologously in archaeal and bacterial expression systems, demonstrating that no other viral proteins are required for VAP formation (7). The mechanism by which VAPs self-assembles in the membrane remains unknown.In the present study we used electron cryotomography to investigate morphological features of SIRV2 replication and the formation of VAPs at different time points after infection. By subtomogram averaging, we determined a 3D map of the VAP. This map, in combination with secondary structure predictions of PVAP and the expression of wild-type (WT) PVAP or a variety of truncation mutants in archaeal, bacterial and eukaryotic cells allows us to propose a model showing how PVAP arranges to form the sevenfold pyramids. These insights are fundamental for understanding how this mechanism can be exploited as a universal tool to engineer the formation and controlled opening of large pores in biological or artificial lipid bilayers.     

Clinical outcome of surgically treated low-grade gliomas: A retrospective analysis of a single institute

Objective

Low grade gliomas (LGGs) are slow-growing primary brain tumors with heterogeneous clinical behaviors. The aim of our study is to review the treatment outcome of 63 patients with LGGs focusing on surgical outcome and the current therapeutic strategy.

Methods

We retrospectively enrolled 63 patients surgically treated for LGGs. The gross total resection (GTR) was performed in 35 patients (60.3%), subtotal resection (STR) was performed in 19 patients (31.7%) and partial resection (PR) or biopsy was performed in 9 patients (14.3%). We analyzed their progression-free survival (PFS), overall survival (OS), and malignant transformation with regard to age, gender, Karnofsky performance score (KPS), clinical presentation, tumor location, radiologic pattern, contrast enhancement, extent of removal, pathologic subtype, chemotherapy (CT) and radiotherapy (RT) treatment.

Results

Among all LGGs, the 3-year OS rate was 80% and the 5-year OS was 76%. The 3-year PFS rate was 83.6% and the 5-year PFS was 25%. The non-eloquent area location showed a longer PFS than the eloquent area location (p = 0.05). Oligodendroglial pathology showed a longer PFS compared to oligoastrocytomas and astrocytomas (p = 0.02). Patients older than 60 years had poorer OS than younger patients (p < 0.05). Female gender had a shorter OS than male gender (p < 0.05), and a KPS of 90 or 100 had a longer OS than a KPS of 80 (p < 0.05). Oligodendroglial pathology statistically correlated with a longer OS (p < 0.05).

Conclusion

The findings from our study, which were confirmed by uni- and multivariate analyses, demonstrated that radical tumor resection was associated with better long-term outcomes and tumor progression for patients with LGG.