Single-Centre Comparative Study of Laparoscopic Versus Open Right Hepatectomy

Background  

Expansion of laparoscopic major hepatectomy is still limited mainly due to the well-recognised technical difficulties compared to open surgery, and doubts regarding the oncological efficiency when major resections are required.     

Bacterial wound contamination during simple and complex spinal procedures. A prospective clinical study

Background context

Spinal procedures have a potential of intraoperative contamination. C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) have been used to diagnose postoperative infections after spinal surgery. However, it has not been demonstrated if there is an association between surgical site contamination and clinical manifestation of postoperative infection based on inflammatory markers and patients' clinical course.

Purpose

The purpose of this prospective study was to evaluate the association between surgical site contamination and the development of a postoperative infection in simple and complex surgical procedures. C-reactive protein and ESR levels were observed. The correlation between their values, surgical time, type of surgical procedures, and contaminated surgical sites was investigated.

Study design

Prospective clinical study.

Patient sample

The study consisted of 40 patients divided into two groups. Group A included 20 patients (mean age, 46.2 years; 12 women and 8 men) who underwent an open discectomy for a lumbar herniated disc. Group B consisted of 20 patients (mean age, 67.9 years; 11 women and 9 men) who underwent a decompression and instrumented fusion for lumbar spinal stenosis. They were followed up for an average of 26.7 months (range, 11–40 months).

Outcome measures

Samples were obtained for cultures in standard time intervals during surgery. The types of bacteria cultured were evaluated, and CRP and ESR levels were measured.

Methods

Simple lumbar discectomy (Group A, 20 patients) and instrumented lumbar decompression for degenerative lumbar stenosis (Group B, 20 patients) were performed in a prospective consecutive series of patients. All patients were operated by the same surgeon in the same operating room. Surgical site preparation in each patient was done by a standard manner. Samples were obtained for cultures in standard time intervals during surgery. C-reactive protein and ESR levels were measured preoperatively on the 3rd, 7th, and 21st postoperative days, and the clinical course of each patient was recorded.

Results

From 40 patients, three patients in Group A and five patients in Group B, a total of eight patients (20%) had positive cultures for bacteria. There was no statistical significance between contamination and duration of surgery in both groups. None of the patients with positive intraoperative cultures developed any clinical signs of superficial or deep postoperative spinal infection, and no additional antibiotic treatment was administered. Three patients with negative cultures developed a postoperative infection. There were no differences in CRP and ESR values between patients with contamination and noncontamination in both groups. C-reactive protein and ESR levels were significantly elevated in complex procedures (Group B) than in simple procedures (Group A). Statistical analysis of CRP and ESR values in both groups and types of bacteria cultured intraoperatively are presented.

Conclusions

The results of this study demonstrate that intraoperative contamination can occur during simple and complex spinal procedures. In the absence of postoperative signs of infection in patients with intraoperative contamination, there is no need of continuing antibiotic treatment. Postoperative kinetics of CRP and ESR showed to be the same in patients with and without intraoperative contamination. Higher levels of inflammatory markers were noted in complex spinal procedures where instrumentation was applied.     

Inference of seed bank parameters in two wild tomato species using ecological and genetic data

Seed and egg dormancy is a prevalent life-history trait in plants and invertebrates whose storage effect buffers against environmental variability, modulates species extinction in fragmented habitats, and increases genetic variation. Experimental evidence for reliable differences in dormancy over evolutionary scales (e.g., differences in seed banks between sister species) is scarce because complex ecological experiments in the field are needed to measure them. To cope with these difficulties, we developed an approximate Bayesian computation (ABC) framework that integrates ecological information on population census sizes in the priors of the parameters, along with a coalescent model accounting simultaneously for seed banks and spatial genetic structuring of populations. We collected SNP data at seven nuclear loci (over 300 SNPs) using a combination of three spatial sampling schemes: population, pooled, and species-wide samples. We provide evidence for the existence of a seed bank in two wild tomato species (Solanum chilense and Solanum peruvianum) found in western South America. Although accounting for uncertainties in ecological data, we infer for each species (i) the past demography and (ii) ecological parameters, such as the germination rate, migration rates, and minimum number of demes in the metapopulation. The inferred difference in germination rate between the two species may reflect divergent seed dormancy adaptations, in agreement with previous population genetic analyses and the ecology of these two sister species: Seeds spend, on average, a shorter time in the soil in the specialist species (S. chilense) than in the generalist species (S. peruvianum).     

Total occlusion of the common carotid artery: a modified classification and its relation to clinical status

To investigate the hemodynamics and clinical presentation of common carotid artery occlusion (CCAO), we reviewed 6,415 patients with suspected carotid artery disease in whom a color Duplex imaging (CDI) examination was performed. According to distal vessel patency, the following CDI classification of CCAO was adopted: type I (patent both distal vessels); type II (isolated patency of external carotid artery); type III (isolated patency of internal carotid artery); and type IV (both distal vessels occluded). Thirty-five (0.5%) cases met the CDI criteria for CCAO. Twenty-nine of those (83%) had at least one patent distal vessel. Ten patients (29%) presented with stroke, 20 (57%) with transient ischemic attacks (TIAs) and five (14%) were asymptomatic. The incidence of stroke was higher in type IV (50%) vs. type II (30%) and in type II vs. type I (10%) lesions. Similarly, TIAs presented more often in type II (67%) and IV (50%) vs. in type I (40%) lesions (p = 0.002). Retrograde flow in the ophthalmic artery and concomitant severe contralateral carotid artery stenosis were more often related with type II and IV lesions (p = 0.02 and 0.04, respectively). CCAO is usually accompanied by patent distal vessel(s). The proposed CCAO classification correlates well with the patients' clinical status and may help to better clarify the outcome of this rare entity. Among the main arteries of the developed collateral circulation, only the flow direction in the ophthalmic artery may be of clinical value.     

Integrity of liposomes in presence of cyclodextrins: effect of liposome type and lipid composition

Liposome stability during incubation in presence of cyclodextrins (CDs) is studied. Dried-rehydrated vesicle (DRV), multilamellar vesicle (MLV) and small unilamellar vesicle (SUV) calcein-encapsulating liposomes, composed of different lipids are formulated, and retention of calcein is followed during vesicle incubation in hydroxypropyl-beta-CD (HP beta-CD), HP gamma-CD or methyl-beta-CD (Me beta-CD), for 24h. Results demonstrate that liposome integrity in cyclodextrins is affected by lipid composition and type. For the same lipid composition calcein release from vesicles is faster in the order: MLV > DRV > SUV. Me beta-CD influences liposome stability most, compared to the other CD's studied. Vesicles composed of saturated phospholipids were found more stable compared to phosphatidyl-choline (PC) liposomes, suggesting that phospholipid saturation and membrane rigidity influences the interaction between liposomal-lipids and CD molecules. Chol (cholesterol) addition in lipid membrane improves PC-liposome integrity, but has opposite or no effect on liposomes consisting of saturated lipids. Decrease of vesicle dispersion turbidity and size distribution in presence of CD, implies that Me beta-CD induces vesicle disruption and solubilization (to micelles). Turbidity measurements confirm that DRV liposomes are affected more than SUV.     

Luteinising hormone-releasing hormone antagonists in prostate cancer therapy

The introduction of androgen blockade therapy using luteinising hormone-releasing hormone (LHRH)/gonadotropin-releasing hormone analogues alone or in combination with non-steroidal antiandrogens has a major impact in both survival and quality of life of patients with locally advanced and metastatic prostate cancer. The effect of LHRH agonists is based on the continuous binding to the LHRH receptor (LHRH-R) on the gonadotrope cells of the pituitary, which although initially stimulate LH release, consequently downregulates the LHRH-R, thereby suppressing serum LH, testosterone levels and 5alpha-dihydrotestosterone levels. Because this initial surge of LH and testosterone can cause adverse consequences in these patients (the so-called flare-up symptoms), immediate inhibition of LH release and testosterone production is desirable and this can be achieved with the use of the LHRH antagonists. In addition, there exist data to support a direct anticancer effect of LHRH antagonists on prostate cancer cells. This review summarises the potential clinical use of the LHRH antagonists in prostate cancer patients.     

Ruptured hemangioma of the umbilical cord and intrauterine fetal death, with review data

A case of intrauterine fetal death with rupture of a hemangioma in the umbilical cord is presented. Hemangiomas are uncommon tumors of the umbilical cord, and their clinical significance is not entirely clear, but associations with polyhydramnios, fetal disseminated intravascular coagulation, and fetal hydrops have been described. In a high proportion of the umbilical cord hemangiomas reported in the literature (32 cases), the fetus had died in utero as in the present case and only ten cases were vital and completely normal infants. Associated malformations and complications of the umbilical cord hemangioma are reviewed.     

p62 ubiquitin binding-associated domain mediated the receptor activator of nuclear factor-kappaB ligand-induced osteoclast formation: a new insight into the pathogenesis of Paget's disease of bone

Paget's disease of bone (PDB) is a debilitating bone disorder characterized by giant osteoclasts, enhanced bone destruction, and irregular bone formation. Recently, mutations in SQSTM1 (also known as p62) have been detected in PDB sufferers, with all mutations resulting in either loss of function or truncation/deletion of the ubiquitin binding-associated (UBA) domain. We hypothesized that mutation in the p62 gene resulting in either deletion or premature termination of the UBA domain accounts for the elevated osteoclastic formation and bone resorption associated with PDB. Remarkably, overexpression of the p62 UBA domain deletion mutant (p62DeltaUBA) significantly enhanced osteoclastogenesis in vitro compared to cells expressing either wild-type p62 (p62WT) or a control vector in a RAW264.7 osteoclastogenic system. Overexpression of p62DeltaUBA potentiated the formation of abnormally large multinucleated osteoclasts and resorption of bone, reminiscent of PDB. Consistent with the enhancement of osteoclastogenesis, overexpression of p62DeltaUBA potentiated receptor activator of nuclear factor-kappaB ligand-induced activation of nuclear factor-kappaB, NFAT, and ERK phosphorylation. Furthermore, as determined by confocal microscopy, deletion of the p62 UBA domain impaired the association of p62 with TRAF6 in the proteasomal compartment. These results suggest that the UBA domain encodes essential regulatory elements required for receptor activator of nuclear factor-kappaB ligand-induced osteoclast formation and bone resorption that may be directly associated with the progression of PDB.     

Fibrin sealant promotes migration and proliferation of human articular chondrocytes: possible involvement of thrombin and protease-activated receptors

Fibrin sealant (FS), a biological adhesive material, has been recently recommended as an adjunct in autologous chondrocyte implantation (ACI). While FS has been shown to possess osteoinductive potential, little is known about its effects on chondrogenic cells. In this study, we assessed the bioactivity of FS (Tisseel) on the migration and proliferation of human articular chondrocytes in vitro. Using a co-culture assay to mimic matrix-induced ACI (MACI), chondrocytes were found to migrate from collagen membranes towards FS within 12 h of culture, with significant migratory activity evident by 24 h. In addition, 5-bromo-2'-deoxyuridine (BrdU) incorporation experiments revealed that thrombin, the active component of the tissue glue, stimulated chondrocyte proliferation, with maximal efficacy observed at 48 h post-stimulation (1-10 U/ml). In an effort to elucidate the molecular mechanisms underlying these thrombin-induced effects, we examined the expression and activation of protease-activated receptors (PARs), established thrombin receptors. Using a combination of RT-PCR and immunohistochemistry, all four PARs were detected in human chondrocytes, with PAR-1 being the major isoform expressed. Moreover, thrombin and a PAR-1, but not other PAR-isotype-specific peptide agonists, were found to induce rapid intracellular Ca2+ responses in human chondrocytes in calcium mobilization assays. Together, these data demonstrate that FS supports both the migration and proliferation of human chondrocytes. We propose that these effects are mediated, at least in part, via thrombin-induced PAR-1 signalling in human chondrocytes.