Residual neuromuscular block as a risk factor for critical respiratory events in the post anesthesia care unit

OBJECTIVE

Residual neuromuscular block is an important postoperative complication associated to the use of neuromuscular blocking drugs. The purpose of this study was to access the incidence of residual neuromuscular block in a post-anesthesia care unit and to evaluate its association with critical respiratory events.

MATERIAL AND METHODS

Prospective cohort study was conducted in a Post Anesthetic Care Unit (PACU) for a period of 3 weeks. Two hundred two adult patients who submitted to scheduled non-cardiac and non-intracranial surgery were eligible to the study. The primary outcome variable was residual neuromuscular block after arrival to PACU that was defined as train-of-four ratio <0.9 and objectively quantified using acceleromyography. Demographic data, perioperative variables, lengths of hospital and recovery room stay and critical respiratory events were recorded. Inadequate emergence was classified in its different forms according to the Richmond agitation and sedation scale 10 min after admission to the recovery room.

RESULTS

Residual neuromuscular block incidence in the post-anesthesia care unit was 29.7% (95% confidence interval: 23.4, 36.1). Patients with residual neuromuscular block had more frequently overall critical respiratory events (51% versus 16%, P<0.001), airway obstruction (10% versus 2%, P=0.029), mild-moderate hypoxemia (23% versus 4%, P<0.001), severe hypoxemia (7% versus 1%, P=0.033), respiratory failure (8% versus 1%, P=0.031), inability to breathe deeply (38% versus 12%, P<0.001) and muscular weakness (16% versus 1%, P<0.001). Residual neuromuscular block was more common after high-risk surgery (53% versus 33%, P=0.011) and was more often associated with post-operative hypoactive emergence as defined by the Richmond Agitation and Sedation Scale (21% versus 6%, P=0.001).

CONCLUSIONS

This study suggests that residual neuromuscular block is common in the PACU and is associated with more frequent critical respiratory events.

PET/CT in the management of metastatic cervical lymphadenopathy from unknown primary site: a seven years retrospective study

OBJECTIVES

To evaluate the accuracy of PET/CT for the diagnostic evaluation of patients presenting cervical node metastasis of suspected unknown primary; furthermore to understand its relative clinical utility and relevance when compared to classic endoscopic investigation approach.

MATERIALS & METHODS

A retrospective study was pursued, collecting information from clinical files of all patients who presented to the Portuguese Institute of Oncology - Oporto, from January 2005 to December 2011, with cervical node metastases whose primary hadn't been found, despite clinical examination and standard imaging (CT scan or MRI) and therefore were submitted to a PET/CT. Among those presenting with non-supraclavicular metastasis patients were subsequently analyzed according to: histopathology; those who performed examination under anaesthesia (EUA) for biopsies either before of after PET/CT.

RESULTS

Eighty nine patients were included in the study. Detection rate was 32.6% with no statistically difference between those with supraclavicular metastases and those with metastases in higher cervical levels (p = 0.24). In this last group (n = 76), 43% patients had had PET/CT and an endoscopy associated with biopsies of the upper aerodigestive tract in different orders, to complete diagnostic workup in cases where the first performed was inconclusive. No statistically difference was found between these two methods (p = 0.25). Most of noticed false negatives were microscopic lesions located deep in the palatine tonsils.

CONCLUSIONS

PET/CT showed to be an useful tool when searching for primary tumours whether metastasis were supraclavicular or located in higher levels of the neck. Despite its good accuracy and detection of tumours previously undetected by EUA with biopsies (missed mainly due to sampling error), up-front negative scan shouldn't preclude performing endoscopies. Being evident that both tools are helpful. It was not possible in this study to find any evidence that could show which one of these two exams should be performed first.

p53 levels in human mammary epithelial cells expressing wild-type and mutant human papillomavirus type 16 (HPV-16) E6 proteins

Human fibroblast cells must overcome both the M1 and the M2 stages of cellular senescence to immortalize, at which point cells almost always express telomerase activity. The human papillomavirus (HPV) oncoproteins, HPV-16 E6 and E7, can block the progression to senescence in fibroblasts by associations with p53 and pRb, respectively. Human mammary epithelial (HME) cells require only HPV-16 E6 to bypass M1, suggesting that pRb may not have a direct role in HME cells senescence. In the present report, we show that only wild-type HPV-16 E6 allows complete degradation of p53, immortalization and reactivation of telomerase activity in HME cells. These results suggest that the ability of HPV-16 wild-type and mutant E6 proteins to degrade p53 in intact HME cells and keratinocytes does not completely correlate with their ability to degrade p53 in a cell-free system. This discrepancy between in vitro and in vivo p53 degradation may be biologically significant and may provide insight into the susceptibility of certain human cells and tissues for reactivation of telomerase and immortalization.

In-vivo analysis of hpv e7 protein association with prb, p107 and p130

The two-hybrid system was used to detect interactions in vivo between HPV E7 and three 'Rb-like proteins', pRb, p107 and p130. The association between pE7 and pRb parallel the oncogenic potential of the specific HPV types. In contrast, the interaction between pE7 and p107 or p130 differ. While the HPV 16 E7 protein associates with the 'Rb-like' proteins strongly, both HPV 18 and 6b E7 proteins bind more weakly. We tested several HPV 6 E7 mutants carrying single amino acid mutations. Substitution of the glycine at position 22 with an aspartate was the only mutation capable of increasing the ability of HPV 6 E7 protein to bind pRb. However, association with p107 and p130 by the HPV 6 E7 protein was also increased by mutation of the arginine at position 4 with an aspartate. These data suggest that pRb, p107 and p130 interact with similar but non-identical domains of pE7. In addition, we used amphotropic retroviruses encoding the HPV 18 E6 and the different E7 genes to analyze their immortalizing activity. The wild-type HPV Is and 16 E7 genes complemented the HPV 18 E6 gene to immortalize human keratinocytes. In comparison, none of the cells infected with HPV 6 E7, wildtype or mutant- encoding retroviruses, became immortal. Thus, our data suggest that HPV 6 E7 lacks a property independent of pRb-association which is required for immortalization of human keratinocytes.

The mechanically adaptive connective tissue of echinoderms: its potential for bio-innovation in applied technology and ecology

Echinoderms possess unique connective tissues, called mutable collagenous tissues (MCTs), which undergo nervously mediated, drastic and reversible or irreversible changes in their mechanical properties. Connective tissue mutability influences all aspects of echinoderm biology and is a key-factor in the ecological success of the phylum. Due to their sensitivity to endogenous or exogenous agents, MCTs may be targets for a number of common pollutants, with potentially drastic effects on vital functions. Besides its ecological relevance, MCT represents a topic with relevance to several applied fields. A promising research route looks at MCTs as a source of inspiration for the development of novel biomaterials. This contribution presents a review of MCT biology, which incorporates recent ultrastructural, biomolecular and biochemical analyses carried out in a biotechnological context.

[Silent sinus syndrome--two cases report]

INTRODUCTION

Silent Sinus Syndrome (SSS) is a rare pathology, characterized by retraction of the maxillary sinus walls, leading to enophthalmos, sometimes diplopia and midfacial depression. It is usually not associated with sinonasal symptoms. Sinus ventilation and drainage stops its progression, but usually cannot reverse the process. This empiric treatment supports the Hypoventilation Theory that would explain the pathogenesis of this disorder.

MATERIALS & METHODS

We describe two cases of SSS. A 65 year-old-man complaining of enophthalmos with an insidious onset whose CT-Scan confirmed SSS. After he was submitted to drainage surgery, the ocular asymmetry showed slight improvement. The second case describes a 34 year-old-woman with a sudden onset enophthalmos associated with diplopia, in only 5 days. She didn't have nasal or sinus related symptoms. CT-scan revealed SSS due to maxillary and ethmoidal sinus. Early endoscopic surgery enabled reversal of enophthalmos and correction of diplopia.

Clinical and molecular characterization of Diastrophic Dysplasia in the Portuguese population

SLC26A2-related dysplasias encompass a spectrum of diseases: from lethal achondrogenesis type 1B (ACG1B; MIM #600972) and atelosteogenesis type 2 (AO2; MIM #256050) to classical diastrophic dysplasia (cDTD; MIM #222600) and recessive multiple epiphyseal dysplasia (rMED; MIM #226900). This study aimed at characterizing clinically, radiologically and molecularly 14 patients affected by non-lethal SLC26A2-related dysplasias and at evaluating genotype-phenotype correlation. Phenotypically, eight patients were classified as cDTD, four patients as rMED and two patients had an intermediate phenotype (mild DTD - mDTD, previously 'DTD variant'). The Arg279Trp mutation was present in all patients, either in homozygosity (resulting in rMED) or in compound heterozygosity with the known severe alleles Arg178Ter or Asn425Asp (resulting in DTD) or with the mutation c.727-1G>C (causing mDTD). The 'Finnish mutation', c.-26+2T>C, and the p.Cys653Ser, both frequent mutations in non-Portuguese populations, were not identified in any of the patients of our cohort and are probably very rare in the Portuguese population. A targeted mutation analysis for p.Arg279Trp and p.Arg178Ter in the Portuguese population allows the identification of approximately 90% of the pathogenic alleles.

Effects of polyandry on male phenotypic diversity

Polyandry has the potential to affect the distribution of phenotypes and to shape the direction of sexual selection. Here, we explore this potential using Trinidadian guppies as a model system and ask whether polyandry leads to directional and/or diversifying selection of male phenotypic traits. In this study, we compare the phenotypic diversity of offspring from multiply and singly sired broods. To quantify phenotypic diversity, we first combine phenotypic traits using multivariate methods, and then take the dispersion of individuals in multivariate space as our measure of diversity. We show that, when each trait is examined separately, polyandry generates offspring with a higher proportion of bright coloration, indicating directional selection. However, our multivariate approach reveals that this directionality is accompanied by an increase in phenotypic diversity. These results suggest that polyandry (i) selects for the production of sons with the preferred brighter colour phenotypes whereas (ii) enhancing the diversity of male sexual traits. Promoting phenotypic diversity may be advantageous in coping with environmental and reproductive variability by increasing long-term fitness.