New trends in head and neck surgery: a prospective evaluation of the Harmonic Scalpel.

BACKGROUND: The use of ultrasonic technology to cut and coagulate tissues with minimal tissue damage has been investigated in general surgery and gynecology. The purpose of this study was to verify the efficacy and applicability of the Harmonic Scalpel in head and neck surgery. MATERIAL/METHODS: A non-randomized study was undertaken on 40 pharyngolaryngectomies, 40 total laryngectomies, 40 radical neck dissections, and 40 superficial parotidectomies performed using the Harmonic Scalpel (80 patients) or "cold knife" dissection (80 patients). The evaluation included operation time, intraoperative blood loss, quantity of neck drainage on the first and second postoperative days, postoperative seroma formation, pattern of wound healing, days of hospitalization, and subjective assessment of postoperative pain. RESULTS: In patients treated with the Harmonic Scalpel, the mean operation time was significantly (p<0.05) shorter (119.1+/-1.35 vs. 156.9+/-1.51), intraoperative blood loss (121.5+/-1.28 vs. 257.5+/-2.32) and the quantity of neck drainage on the first (47+/-0.87 vs. 89+/-1.28) and second (38.7+/-0.86 vs. 75.5+/-1.34) postoperative days were significantly less, and the days of hospitalization (6.67+/-0.48 vs. 8.8+/-0.58) and the pain scores (3.24+/-0.63 vs. 5.91+/-0.83) were significantly lower than in the "cold knife" group. No postoperative complications were noted in the Harmonic Scalpel group. CONCLUSIONS: The use of the Harmonic Scalpel in head and neck surgery is safe and confers some advantages over conventional methods of head and neck dissection.     

Tiratricol neutralizes bacterial endotoxins and reduces lipopolysaccharide-induced TNF-alpha production in the cell

The screening of a commercially available library of compounds has proved a successful strategy for the identification of a lead compound in a drug discovery programme. Here, we analysed 880 off-patent drugs, which initially comprised the Prestwick Chemical library, as sources of bacterial endotoxin neutralizers. We identified 3,3',5-triiodo-thyroacetic acid (tiratricol) as a non-antibacterial compound that neutralizes the toxic lipopolysaccharide.     

Anesthesia (13)

An in vitro study of dural lesions produced by 25‐gauge Quincke and Whitacre needles evaluated by scanning electron microscopy. (Hospital de Mostoles, Madrid Spain) Reg Anesth Pain Med 2000;25:393–402. This study evaluated the dural lesions produced by Whitacre and Quincke spinal needles in the external and internal surface of the dura mater of the lower spine area in an attempt to gain more insight into the pathophysiology of postdural puncture headaches (PDPH). The T11‐L4 dural membranes from 5 fresh (immediately after extraction of organs for transplantation) male patients declared brain dead, ages 23, 46, 48, 55, and 60, were excised by anterior laminectomy. Morphologic orientation of the membrane and normal pH were maintained; 100 punctures at 90‐degree angles were done with a new needle each time, 50 with 25‐gauge Whitacre and 50 with 25‐gauge Quincke needles. Half of the punctures with the Quincke needles were done with the bevel in the parallel direction to the axis of the spinal cord, and the rest with the bevel perpendicular to it. Fixation in solutions of 2.5% glutaraldehyde phosphate buffer, followed by dehydration with acetone, was done 15 min after the punctures. The acetone was removed and the specimens were metallized with carbon followed by gold and inspected under a scanning electron microscope. When the area of the dural lesions found in the external and internal surfaces produced by the 2 types of needles was compared, no significant differences were found. The percentage of lesion closing area with the Quincke needles was 88.3% and 82.7% in the external and internal surfaces, respectively. With the Whitacre needles, the percentage of closing was 86.8% and 84.8% in the epidural and arachnoid surfaces, respectively. There were differences noted in the morphology of the lesions. The Whitacre needles produced coarse lesions with significant destruction in the dura's fibers while the Quincke needles produced a “U”‐shaped lesion (flap) that mimics the opened lid of a tin can, regardless of the tip's direction. Conclude that the needles produced lesions in the dura with different morphology and characteristics. Lesions with the Quincke needles resulted in a clean‐cut opening in the dural membrane while the Whitacre needle produced a more traumatic opening with tearing and severe disruption of the collagen fibers. The lower incidence of PDPH seen in the Whitacre needles may be explained, in part, by the inflammatory reaction produced by the tearing of the collagen fibers after dural penetration. The inflammatory reaction may result in a significant edema, which may act as a plug limiting the leakage of the cerebrospinal fluid. Comment by Andrew D. Rosenberg, MD. This is an interesting article that explains why a patient will develop a postdural puncture headache (PDPH) after receiving a spinal with a Quincke needle and not after a Whitacre‐type needle. The explanation is based more upon an inflammatory reaction than the direction of the needle cut. The Quincke needle appears to make a sharp cut while the Whitacre needle induced an inflammatory response including edema, which could block off the dura from leaking. It is very interesting that the response seen after the Whitacre needle was utilized occurred as quickly as it did. The article introduces the question as to whether a Quincke needle or a Whitacre needle is associated with more trauma to the dura, and which is better for decreasing the incidence of PDPD.     

Catheter-related infection in critically ill patients

Objective To describe the incidence of the catheter-related local infection (CRLI) and catheter-related bloodstream infection (CRBSI) of central venous catheters (CVCs) and arterial catheters (ACs).Design Prospective, observational study.Setting A 24-bed medical-surgical intensive care unit of a 650-bed university hospital.Patients We included 988 consecutive patients admitted to the ICU during 18 months.Measurements The incidence density of CRLI and CRBSI, per 1000 catheter-days, of CVC and AC.Results Central venous catheters had a significantly higher incidence density of CRLI (4.74 vs 0.97/1,000 catheter-days; p<0.001) than ACs. Femoral venous access had a higher incidence density of CRLI than subclavian (13.15 vs 1.81/1,000 catheter-days, p=0.003) and than peripheral access (13.15 vs 2.30/1,000 catheter-days, p<0.001). Jugular venous access had a higher incidence density of CRLI (6.29 vs 1.81/1,000 catheter-days, p<0.001) than subclavian access. We found no significant differences in the incidence density of CRLI and CRBSI between the different AC accesses.Conclusions In the CDC guidelines, catheter insertion at the subclavian site is recommended in preference to femoral and jugular accesses, and there is no recommendation about AC site insertion. Our data support these recommendations about CVCs. Because the AC infection rate was very low, our study suggests that the access site is probably not of major importance for this type of catheter.     

A rapid and sensitive method to detect specific human lymphocyte antigen (HLA) class II alleles associated with celiac disease.

BACKGROUND: Celiac disease (CD) is a complex disorder triggered by gluten affecting genetically predisposed individuals. More than 90% of patients carry human lymphocyte antigen (HLA)-DQ2 (DQA1*05, DQB1*02) and/or HLA-DQ8 (DQA1*03, DQB1*0302). We propose the use of the DQ-CD Typing kit that allows identification of the HLA class II alleles (DQA1*0201,*03,*05, DQB1*02,*0302, DRB1*03,*04,*07) selected to be informative in the CD risk evaluation and of a second kit, namely DQ-CD Zygosis, for DQB1*02 homozygosity determination. METHODS: The study was performed on a cohort of 100 individuals previously HLA typed with commercial kits. Fresh blood or previously extracted DNA was amplified in a unique PCR program using allele-specific primers and visualized on agarose gel. RESULTS: DNA amplification yielded strong and clear products without non specific signals or ghost bands. All the samples showed the expected alleles in accordance with the previous HLA typing. CONCLUSIONS: The DQ-CD Typing and Zygosis kits are fast, simple, economical and accurate tools that can be used to determinate the HLA-DQ2/DQ8 status in laboratory practice addressed for the diagnosis of CD. Molecular HLA testing is considered a valid support in the confirmation/exclusion of CD, especially in high-risk groups, such as CD relatives, or when serological and histological data are ambiguous.     

Quantification in time-domain diffuse optical tomography using Mellin-Laplace transforms

Simulations and phantom measurements are used to evaluate the ability of time-domain diffuse optical tomography using Mellin-Laplace transforms to quantify the absorption perturbation of centimetric objects immersed at depth 1-2 cm in turbid media. We find that the estimated absorption coefficient varies almost linearly with the absorption change in the range of 0-0.15 cm⁻¹ but is underestimated by a factor that depends on the inclusion depth (~2, 3 and 6 for depths of 1.0, 1.5 and 2.0 cm respectively). For larger absorption changes, the variation is sublinear with ~20% decrease for δμ_a = 0.37 cm⁻¹. By contrast, constraining the absorption change to the actual volume of the inclusion may considerably improve the accuracy and linearity of the reconstructed absorption.OCIS codes: (170.6920) Time-resolved imaging, (110.6960) Tomography, (100.3010) Image reconstruction techniques, (110.0113) Imaging through turbid media, (030.5260) Photon counting, (230.5160) Photodetectors     

Estándares de calidad en la cirugía oncológica pancreática en España

Introduction

To establish quality standards in oncologic surgery is a complex but necessary challenge to improve surgical outcomes. Unlike other tumors, there are no well-defined quality standards in pancreatic cancer. The aim of this study is to identify quality indicators in pancreatic oncologic surgery in Spain as well as their acceptable limits of variability.

Predicting the spectrum of TCR repertoire sharing with a data-driven model of recombination

Despite the extreme diversity of T-cell repertoires, many identical T-cell receptor (TCR) sequences are found in a large number of individual mice and humans. These widely shared sequences, often referred to as “public,” have been suggested to be over-represented due to their potential immune functionality or their ease of generation by V(D)J recombination. Here, we show that even for large cohorts, the observed degree of sharing of TCR sequences between individuals is well predicted by a model accounting for the known quantitative statistical biases in the generation process, together with a simple model of thymic selection. Whether a sequence is shared by many individuals is predicted to depend on the number of queried individuals and the sampling depth, as well as on the sequence itself, in agreement with the data. We introduce the degree of publicness conditional on the queried cohort size and the size of the sampled repertoires. Based on these observations, we propose a public/private sequence classifier, “PUBLIC” (Public Universal Binary Likelihood Inference Classifier), based on the generation probability, which performs very well even for small cohort sizes.