The significance of glycocalyx in surgery.

INTRODUCTION: Surgical treatment is associated with an unwanted response of the organism to the so-called surgical trauma. This response is called surgical stress. Ischaemia-reperfusion injury is one of essential causes of tissue damage. It comprises functional and structural changes in tissue that occur after the restoration of circulation, after an episode of ischaemia. Necrosis of irreversibly changed cells and endothelial and mitochondrial-induced tissue swelling occur. METHODS: Physiology, pathophysiology of endothelial glycocalyx: Endothelial glycocalyx is a 0.2 to 5 micrometres thin heteropolysaccharide layer that covers the endothelium on its intraluminal side. Backbone molecules of the glycocalyx include proteoglycans, glycoproteins, and glycosaminoglycans. Damage of the endothelial glycocalyx was described in trauma patients, in patients with septic shock, in ischemia and reperfusion injury, and during extensive surgical procedures. Approaches to prevent endothelial glycocalyx damage: Remote ischemic preconditioning was tested as a method of ischemia and reperfusion injury prevention during and after surgery. Nevertheless, the expected effect was not confirmed in performed meta-analyses. Endothelial glycocalyx damage can be prevented pharmacologically with a broad spectrum of substances, such as antithrombin III, doxycycline, hydrocortisone, etanercept, or nitric oxide donors. Hydrogen inhalation or albumin affects glycocalyx positively. Sulodexide provides a positive effect on the protection and reparation of endothelial glycocalyx. This proteoglycan with antithrombotic, fibrinolytic, hypofibrinogenemic, and lipolytic function is used for the treatment of venous diseases, ischaemic heart disease, and peripheral arterial disease. A positive effect of sulodexide on renal dysfunction was documented in a model of ischaemia and reperfusion injury. Equally, a positive effect of sulodexide was described on endothelium repair after its mechanical damage. CONCLUSION: Further research needs to be performed to evaluate the effect of endothelium-protectives on glycocalyx damage prevention and repair in ischaemia and reperfusion models involving large laboratory animals or in clinical trials in patients undergoing surgical revascularisation procedures.

Tissue-specific fatty acid composition, cellularity, and gene expression in diverse cattle breeds.

The nutritional quality of beef relates to the fatty acid (FA) composition of bovine adipose tissue. Those molecular mechanisms that induce the differing amounts and composition of fat in cattle breeds according to age at maturity and purpose of production remain unclear. Therefore, this study investigated the composition of total FAs, adipocyte size, and expression of some key genes involved in several adipogenesis and lipogenesis pathways measured in distinct adipose tissue depots from bulls of the genetically diverse cattle breeds Aberdeen Angus (n = 9), Gascon (n = 10), Holstein (n = 9), and Fleckvieh (n = 10). The animals were finished under identical housing and feeding conditions until slaughter at a similar age of 17 months. After slaughter, cod adipose tissue (CAT), subcutaneous adipose tissue (SAT), and M. longissimus lumborum (MLL) samples were collected. The saturated FA proportions were higher (P < .01) in CAT than in SAT across all breeds, whereas monounsaturated FA proportions were consistently higher (P < .001) in SAT compared to CAT and MLL. Aberdeen Angus bulls were distinguished from the other breeds in the proportions of mostly de novo synthesized C14:0, C16:0, C14:1n-5, C16:1n-7, and conjugated linoleic acid (P < .05). Adipocyte size decreased in the order CAT > SAT > MLL, and the largest adipocytes were observed in CAT of Holstein bulls (P < .05). Gene expression differences were more pronounced between adipose tissue depots than between breeds. The expression levels of ACACA, FASN, and SCD1 genes were related to tissue-specific, and to a lesser extent also breed-specific, differences in FA composition.

Associations of polymorphisms in bovine DGAT1, FABP4, FASN, and PPARGC1A genes with intramuscular fat content and the fatty acid composition of muscle and subcutaneous fat in Fleckvieh bulls.

Allelic and genotypic distribution of polymorphisms in diacylglycerol acyltransferase 1 (DGAT1), fatty acid binding protein 4 (FABP4), fatty acid synthase (FASN), and peroxisome proliferator-activated receptor-γ coactivator-1α (PPARGC1A) genes were assessed in 679 Fleckvieh bulls. Single-locus genotype effects and the combined effect of the two polymorphisms within the FASN gene were evaluated for association with the intramuscular fat content and fatty acid profile determined in muscle and subcutaneous fat. The FASN (g.16024G>A) and FASN (g.17924A>G) polymorphisms were significantly associated mainly with C14:0, C16:0, and C18:1 n-9 concentrations as well as with the atherogenic index. The proportion of explained phenotypic variation markedly increased when the effect of a combination of the two polymorphisms within the FASN gene was tested, with the highest values of 8.6% and 14.8%, respectively, observed for C14:0 in muscle and subcutaneous fat. With a focus on improving the fatty acid composition of beef, the results of this study provide valuable information about the markers applicable in marker-assisted selection.

Effect of sex and age on bovine muscle and adipose fatty acid composition and stearoyl-CoA desaturase mRNA expression.

The objective of the study was to investigate the effects of sex and slaughter age on the fatty acid (FA) composition and stearoyl-CoA desaturase gene expression in muscle and adipose tissue. Twenty-four Charolais × Simmental crossbred bulls and heifers were raised under similar conditions and slaughtered at 14 or 18 months of age. The total amount of FA in muscle increased markedly in older animals with higher contents of monounsaturated FA (MUFA) in heifers than bulls. The proportions of MUFA and desaturation indices were higher in heifers, whereas polyunsaturated FA were higher in bulls in both muscle and subcutaneous adipose tissue. The results of this study demonstrated sex-dependent differences in the FA composition of muscle and subcutaneous adipose tissue from cattle slaughtered at different ages. The expression of the stearoyl-CoA desaturase gene was higher in the adipose tissue of heifers compared to bulls, and its variation partly contributed to sex- and age-differences in the FA composition of bovine adipose tissue.

The polymorphisms of stearoyl-CoA desaturase (SCD1) and sterol regulatory element binding protein-1 (SREBP-1) genes and their association with the fatty acid profile of muscle and subcutaneous fat in Fleckvieh bulls.

The previously reported genetic polymorphisms of the stearoyl-CoA desaturase (SCD1) and sterol regulatory element binding protein-1 (SREBP-1) genes were investigated in Fleckvieh bulls using the PCR-RFLP and AS-PCR methods, respectively. The genomic DNA was obtained from a total of 370 bulls. The frequencies of alleles A and V of the single nucleotide polymorphism in exon 5 of the SCD1 gene (SNP 878C>T) were 0.555 and 0.445, respectively. In the 84-bp Ins/Del polymorphism in intron 5 of the SREBP-1 gene, the frequency of the L allele (insertion) was markedly higher (0.920) than that of the S allele (deletion; 0.080). Fatty acid profile was determined in a total of 367 samples of muscle fat (MSF) and 150 samples of subcutaneous fat (SCF). The AA genotype of SCD1 polymorphism showed a lower content of C18:0 (P<0.01) and higher contents of C14:1 cis-9 (P<0.001) and C18:1 cis-9 (P<0.05) in MSF compared to the VV genotype. As a result, the bulls with genotypes AA or AV had lower SFA (P<0.01), higher MUFA (P<0.05) and higher MUFA/SFA (P<0.01) than VV animals. The results obtained for SCF were similar. The SREBP-1 polymorphism was associated with a higher content of C14:1 cis-9 (P<0.01) in the LS compared to LL genotype in SCF. The results of this study demonstrated the existence of the polymorphisms in the SCD1 and SREBP-1 genes in the population of Fleckvieh cattle and their associations with the concentrations of several MSF and SCF fatty acids.

Parthenogenetic activation of pig oocytes using pulsatile treatment with a nitric oxide donor.

The nitric oxide donor (+)-S-nitroso-N-acetylpenicillamine (SNAP) is capable of inducing parthenogenetic activation in pig oocytes matured in vitro. However, quite a long exposure to the nitric oxide donor, exceeding 10 h, is necessary for successful oocyte activation. Repeated short-term treatment with 2 mm SNAP significantly increased the activation rates despite the fact that the overall exposure time to the nitric oxide donor did not exceed 4 h. With regard to the activation rate, 12 repeated treatments lasting 10 min each were found to be the most efficient regimen (63.3%). The continuous exposure to the nitric oxide donor for the same overall time induced parthenogenetic activation in 12.5% oocytes (2-h continuous treatment with 2 mm SNAP). The development of parthenogenetic embryos increased after repeated short-term treatment with SNAP. After continuous treatment with 2 mm SNAP for 10 h, only 6.7% of the oocytes cleaved, and none developed beyond the 4-cell stage. Thirty-minute treatment repeated four times with 2 mm SNAP induced cleavage in 37.5% of the oocytes, 18.3% developed to the morula stage, and 6.7% reached the blastocyst stage. Based on the results, it is concluded that pulsatile treatment can significantly improve parthenogenetic activation rate when compared with the continuous treatment using nitric oxide donors.

Ultrastructural localisation of calcium deposits in pig ovarian follicles.

Calcium intracellular signaling regulates many intracellular events including oocyte maturation. This signaling is strongly dependent on the influx of calcium ions from extracellular spaces and on the state of intracellular calcium stores. In this study, intracellular calcium deposits were detected in follicle-enclosed pig oocytes using the combined oxalate-pyroantimonate method. These deposits were observed in the nucleus, the mitochondria, the cytoplasm, and on the surface of lipid droplets. The amount of calcium deposits was expressed as a percentage of the area of the respective cellular compartment, which is covered with calcium deposits on ultrathin sections. The distribution of calcium deposits in oocytes changed during folliculogenesis. The amount of calcium deposits in nuclei (1.11% of the area of oocyte nuclei) and cytoplasm (1.02%) in oocytes from secondary and early antral follicles (0.90% nuclei; 0.99% cytoplasm) is significantly lower (P < 0.05) than the amount of calcium deposits in these compartments in oocytes from primary follicles (2.51% nuclei; 2.34% cytoplasm) or antral follicles with growing oocyte (2.91% nuclei; 2.21% cytoplasm). The amount of calcium deposits in mitochondria of oocytes from primary follicles (1.27%) or antral follicles with growing oocyte (1.14%) is significantly lower (P < 0.05) than in the nucleus (2.51% in oocytes from primary follicles; 2.91% in growing oocytes from antral follicles) or cytoplasm (2.34% in oocytes from primary follicles; 2.21% in growing oocytes from antral follicles). The amount of calcium deposits in the cytoplasm of fully-grown oocytes (1.46%) dropped to levels significantly lower (P < 0.05) than those observed in the oocyte nucleus (2.29%). On the basis of these data, we can conclude that the population of follicles on pig ovaries differs in the distribution and concentration of calcium deposits in oocytes, and these changes may be involved in the regulation of the meiotic competence of oocytes.

Ultrastructural localisation of calcium deposits in the mouse ovary.

Follicle-enclosed mouse oocytes contain numerous calcium deposits. The ultrastructural distribution of calcium deposits in the nuclei, mitochondria and cytoplasm of mouse oocytes and granulosa cells of primary, secondary and antral follicles was examined using the combined oxalate-pyroantimonate method. The mitochondria of oocytes from all types of follicles had the highest levels of calcium deposits of all oocyte compartments, with the exception of primary follicles, in which oocyte nuclei contained the same level of calcium deposits as the mitochondria. Calcium deposits in the cytoplasm of oocytes from primary follicles were significantly lower than those in the cytoplasm of oocytes from secondary and antral follicles. Calcium deposits in the cytoplasm of granulosa cells were significantly lower than calcium deposits in the mitochondria of granulosa cells and this difference persisted throughout all categories of follicles. Calcium deposits in the nuclei of granulosa cells did not differ from levels in the mitochondria in primary and secondary follicles. In contrast, the nuclei of granulosa cells from antral follicles had lower levels of calcium deposits than the mitochondria. The differences observed in calcium deposits in various cellular compartments in oocytes and granulosa cells in the follicles of ovaries of adult mice can be attributed to their acquisition of meiotic competence and follicular development.

Pronator syndrome.

Although pronator syndrome is often misdiagnosed and does not occur as frequently as carpal tunnel syndrome, its clinical features are well described, and the diagnosis should be made if the clinical features are understood and reasonable suspicion exists. The differentiating features between carpal tunnel syndrome and pronator syndrome should be understood, and evaluation for one site of compressive neuropathy of the median nerve always should include the other potential sites. When the correct diagnosis is made, pronator syndrome can be successfully treated nonoperatively or surgically, if necessary.

A comparison of plate and pin fixation for arthrodesis of the rheumatoid wrist.

This retrospective study compared plate fixation versus pin fixation in 57 patients with rheumatoid arthritis who underwent wrist arthrodesis. Fixation was achieved by using plates in 32 patients and longitudinal pins in 25 patients. Clinical follow-up averaged 29 months (range: 12-57 months) and radiographic follow-up averaged 16 months (range 12-39 months). Union occurred in 97% of the wrists fixed with plates and in 96% of the wrists fixed with pins. There were 6 (19%) complications in the plate group and 7 (28%) complications in the pin group. Three (12%) wrists fixed with pins moved from the immediate postoperative position to a position of relative volar flexion, while radiographs showed no changes in wrist position in the plate group. With both methods, successful arthrodesis stabilized the wrist in a high percentage of patients. Plate fixation offers an excellent alternative method for arthrodesis of the rheumatoid wrist.

The Mitek bone anchor: application to the hand, wrist and elbow.

Mitek (Norwood, MA) bone anchors were used to attach soft tissue to the bones of the hand, wrist, and elbow in 66 procedures (166 anchors). The technical difficulties, initial fixation, long-term stability, and postoperative complications were retrospectively reviewed. The technique was easy to learn and to use. Intraoperatively, secure fixation of soft tissue to bone was accomplished in every case, and follow-up x-ray films showed that 65 of the implants remained securely anchored in bone. The far cortex was penetrated six times, resulting in two complications. The Mitek bone anchor is an excellent technique for achieving soft-tissue fixation in the hand and upper extremity, but penetration of the far cortex should be avoided.

A practical method to prevent dark-cutting (DFD) in beef.

A method for the prevention of dark-cutting in beef, based on recognition of social relationships within groups of bulls, was tested on 2234 bulls slaughtered under commercial conditions. When the influence of time between loading the animals and slaughter was eliminated statistically, the bulls of the socially stablized group showed the lowest pH(24) values, whereas those of the socially unstable group showed the highest ones. When the type of social group was eliminated statistically, the earlier slaughtered animals had lower pH(24) values than those slaughtered later. When the two major factors were integrated, there was no statistically significant difference in the pH(24) values in bulls of the socially stabilized group whether they were slaughtered immediately after transport or during the following day. In contrast, in bulls from the socially unstable group, the pH(24) values increased substantially after overnight lairage at the abattoir. In conclusion, for longer transportion, bulls from loose housing with stable social relationships should be used. It is necessary to keep the same social groups from loading to slaughter, strictly avoiding any mixing of strange bulls. Bulls from tethered stalls should be transported and slaughtered within as short a time after regrouping as possible.

Peripheral tears of the meniscus. The effect of open versus arthroscopic repair on intraarticular contact stresses in the human knee.

The mechanical properties of the repaired meniscus may affect its ability to heal and to protect the articular surface against degenerative changes. We compared the immediate biomechanical consequences of open versus arthroscopic repair in the human cadaver knee. Additionally, having measured postoperative stresses at various degrees of knee flexion, we have addressed the effect of tethering of the meniscus, a question relevant to both meniscus repair and replacement. Peak stresses were measured by the Pressensor system. Fresh human cadaver knees were subjected to loading in an Instron unit, on an unconstrained base. Instantaneous loads were applied with the knee in 0 degree, 30 degrees, or 60 degrees of flexion, and stress distributions were measured after repair of a 2 cm peripheral tear, by an open or arthroscopic approach. The results of loading experiments on five knees revealed no statistically significant differences between stresses after the two repairs. Similarly, there was no statistically significant difference between the normal and repaired menisci. In our model, this suggests that the immediate biomechanical consequences of open and arthroscopic repair are equivalent and that the "tethered" meniscus distributes loads as well as the normal meniscus.

Exercise tolerance changes following renal transplantation.

Maximal exercise capacity was measured in 20 nondiabetic patients with end-stage renal disease before and soon after successful renal transplantation. Maximal oxygen consumption increased significantly in all patients posttransplant. Increases in maximal heart rate and heart rates at 70% of maximal levels were also observed. The changes in maximal oxygen consumption were not significantly correlated with changes in hematocrit. The removal of uremia may result in improved functioning of one or more of the systems involved in oxygen transport and utilization that determine exercise capacity.

Exercise capacity in hemodialysis, CAPD, and renal transplant patients.

Eighteen hemodialysis, 12 chronic ambulatory peritoneal dialysis (CAPD), and 20 renal transplant patients performed maximal treadmill exercise tests. Heart rates and blood pressures were determined every minute and maximal oxygen consumption was measured directly. Exercise capacity as measured by VO2 max is low in dialysis patients and similar to sedentary normal individuals in renal transplant patients. Maximal heart rates were significantly lower in hemodialysis patients than transplant recipients. The lower exercise tolerance in end-stage renal disease indicates that most patients regardless of the treatment mode could benefit from attempts through exercise training to increase physical working capacity.