Real-time visualization of ultrasound-guided retrobulbar blockade: an imaging study

Background Retrobulbar anaesthesia allows eye surgery in awake patients. Severe complications of the blind techniques are reported. Ultrasound-guided needle introduction and direct visualization of the spread of local anaesthetic may improve quality and safety of retrobulbar anaesthesia. Therefore, we developed a new ultrasound-guided technique using human cadavers. Methods In total, 20 blocks on both sides in 10 embalmed human cadavers were performed. Using a small curved array transducer and a long-axis approach, a 22 G short bevel needle was introduced under ultrasound guidance lateral and caudal of the eyeball until the needle tip was seen 2 mm away from the optic nerve. At this point, 2 ml of contrast dye as a substitute for local anaesthetic was injected. Immediately after the injection, the spread of the contrast dye was documented by means of CT scans performed in each cadaver. Results The CT scans showed the distribution of the contrast dye in the muscle cone and behind the posterior sclera in all but one case. No contrast dye was found inside the optic nerve or inside the eyeball. In one case, there could be an additional trace of contrast dye behind the orbita. Conclusions Our new ultrasound-guided technique has the potential to improve safety and efficacy of the procedure by direct visualization of the needle placement and the distribution of the injected fluid. Furthermore, the precise injection near the optic nerve could lead to a reduction of the amount of the local anaesthetic needed with fewer related complication

Ultrasound-guided paravertebral puncture and placement of catheters in human cadavers: an imaging study

Background During paravertebral block, the anterolateral limit of the paravertebral space, which consists of the pleura, should preferably not be perforated. Also it is possible that, during the block, the constant superior costotransverse ligament can be missed in the loss-of-resistance technique. We therefore aimed to develop a new technique for an ultrasound-guided puncture of the paravertebral space. Methods We performed 20 punctures and catheter placements in 10 human cadavers. A sonographic view showing the pleura and the superior costotransverse ligament was obtained with a slightly oblique scan using a curved array transducer. After inline approach, injection of 10 ml normal saline confirmed the correct position of the needle tip, distended the space, and enabled catheter insertion. The spread of contrast dye injected through the catheters was assessed by CT scans. Results The superior costotransverse ligament and the paravertebral space were easy to identify. The needle tip reached the paravertebral space without problems under visualization. In contrast, the introduction of the catheter was difficult. The CT scan revealed a correct paravertebral spread of contrast in 11 cases. Out of the remaining, one catheter was found in the pleural space, in six cases there was an epidural, and in two cases there was a prevertebral spread of contrast dye. Conclusions We successfully developed a technique for an accurate ultrasound-guided puncture of the paravertebral space. We also showed that when a catheter is introduced through the needle with the tip lying in the paravertebral space, there is a high probability of catheter misplacement into the epidural, mediastinal, or pleural space

Ultrasound-guided thoracic paravertebral puncture and placement of catheters in human cadavers: where do catheters go?†

Background Paravertebral regional anaesthesia is used to treat pain after several surgical procedures. This study aimed to improve on our first published ultrasound-guided approach to the paravertebral space (PVS) and to investigate a possible discrepancy between the needle, catheter, and contrast dye position. Methods In 10 cadavers, we conducted 26 ultrasound-guided paravertebral approaches combined with loss of resistance (LOR) and after an interim analysis performed 36 novel, pure ultrasound-guided (PUSG) paravertebral approaches. Needle-tip position was controlled by a first computed tomography (CT) scan. After placement of the catheters, the tips were assessed by a second CT and the spread of injected contrast dye was assessed by further CT scans. The part of the PVS near the intervertebral foramen was defined as the primary target to reach. Results The first CT scans assessing 62 needle tips revealed that: 13 (50%) of LOR and 34 (94%) of PUSG approaches were at the target; and two (8%) LOR and no PUSG approaches were outside the PVS. With the second CT scans 60 catheter-tip positions were analysed: three (12%) of LOR and five (14%) of PUSG approaches were at the target, three (12%) of LOR and two (6%) of PUSG approaches were outside the PVS. No catheters were detected in the epidural space. In two cases, insertion of the catheter was not possible. In cases with major epidural contrast, the widest contrast dye spread was 7.7 (3.5) [mean (sd)] vertebral segments. Conclusions Our new PUSG technique has a high success rate for paravertebral needle placement. Although needles were correctly positioned, catheters were usually found distant from the needle-tip positio

Ultrasound-guided percutaneous tracheal puncture: a computer-tomographic controlled study in cadavers

Background Ultrasound-guided techniques are increasingly used in anaesthetic practice to identify tissues beneath the skin and to increase the accuracy of placement of needles close to targeted structures. To examine ultrasound's usefulness for dilatational tracheostomy, we performed ultrasound-guided tracheal punctures in human cadavers followed by computer-tomographic (CT) control. Methods The trachea of nine cadavers was punctured using an in-plane approach with a longitudinal ultrasound visualization of the trachea. As soon as a loss of resistance was felt, or air/fluid could be aspirated into the attached syringe, the syringe was disconnected and the ultrasound transducer set aside. Thereafter, a cricothyroidotomy guidewire was inserted through the needle into the trachea. The needle was then removed, leaving the wire in place and a control CT imaging of the neck and the chest was performed. Primary outcome was successful wire insertion into the trachea. Results Tracheal puncture and wire insertion was successful in eight of nine cadavers at the first attempt and in one at the second attempt (total of 10 puncture attempts, nine successful). In eight of nine successfully inserted wires, the wire was placed on the defined midline. Conclusions Ultrasound guidance can facilitate successful tracheal puncture. However, combining an in-plane approach with a longitudinal ultrasound visualization of the trachea neither guarantees an exact midline puncture nor allows detection of a misplaced guidewir

USE OF DIMETHYL SULPHOXIDE FOR PRESERVING CORNEAL TISSUE*t

SINCE it was discovered by We have been concerned with retaining the viability of corneal tissue after freezing and in the past Our need to maintain a supply of stored corneae for keratoplasty prompted us to set up an experiment to evaluate the usefulness of dimethyl sulphoxide in preserving the viability of cornea during freezing. Experiment.-Our purpose was to compare the preserving qualities of dimethyl sulphoxide with those of glycerol during the storage of corneal tissue at -64°C. Concentrations of 15 per cent./V glycerol and 15 per cent./V dimethyl sulphoxide, both in Hank's balanced salt solution, were used. Corneal material from rabbits, cats, and dogs was obtained from eyes removed as soon as possible after death, usually within 30 minutes. Pig and ox corneae were obtained from eyes removed approximately 4 hours after death. Method.-The eyes were soaked for 10 minutes in a balanced salt solution containing 200 units penicillin and 75 mg. streptomycin per ml. Then the corneae were removed and washed again in balanced salt solution and antibiotics. Each

Ultrasound-guided paravertebral puncture and placement of catheters in human cadavers: an imaging study

BACKGROUND: During paravertebral block, the anterolateral limit of the paravertebral space, which consists of the pleura, should preferably not be perforated. Also it is possible that, during the block, the constant superior costotransverse ligament can be missed in the loss-of-resistance technique. We therefore aimed to develop a new technique for an ultrasound-guided puncture of the paravertebral space. METHODS: We performed 20 punctures and catheter placements in 10 human cadavers. A sonographic view showing the pleura and the superior costotransverse ligament was obtained with a slightly oblique scan using a curved array transducer. After inline approach, injection of 10 ml normal saline confirmed the correct position of the needle tip, distended the space, and enabled catheter insertion. The spread of contrast dye injected through the catheters was assessed by CT scans. RESULTS: The superior costotransverse ligament and the paravertebral space were easy to identify. The needle tip reached the paravertebral space without problems under visualization. In contrast, the introduction of the catheter was difficult. The CT scan revealed a correct paravertebral spread of contrast in 11 cases. Out of the remaining, one catheter was found in the pleural space, in six cases there was an epidural, and in two cases there was a prevertebral spread of contrast dye. CONCLUSIONS: We successfully developed a technique for an accurate ultrasound-guided puncture of the paravertebral space. We also showed that when a catheter is introduced through the needle with the tip lying in the paravertebral space, there is a high probability of catheter misplacement into the epidural, mediastinal, or pleural spaces

Family practitioners' top medical priorities when managing patients with multimorbidity: a cross-sectional study.

Managing multiple chronic and acute conditions in patients with multimorbidity requires setting medical priorities. How family practitioners (FPs) rank medical priorities between highly, moderately, or rarely prevalent chronic conditions (CCs) has never been described. The authors hypothesised that there was no relationship between the prevalence of CCs and their medical priority ranking in individual patients with multimorbidity. To describe FPs' medical priority ranking of conditions relative to their prevalence in patients with multimorbidity. This cross-sectional study of 100 FPs in Switzerland included patients with ≥3 CCs on a predefined list of 75 items from the International Classification of Primary Care 2 (ICPC-2); other conditions could be added. FPs ranked all conditions by their medical priority. Priority ranking and distribution were calculated for each condition separately and for the top three priorities together. The sample contained 888 patients aged 28-98 years (mean 73), of which 48.2% were male. Included patients had 3-19 conditions (median 7; interquantile range [IQR] 6-9). FPs used 74/75 CCs from the predefined list, of which 27 were highly prevalent (>5%). In total, 336 different conditions were recorded. Highly prevalent CCs were only the top medical priority in 66%, and the first three priorities in 33%, of cases. No correlation was found between prevalence and the ranking of medical priorities. FPs faced a great diversity of different conditions in their patients with multimorbidity, with nearly every condition being found at nearly every rank of medical priority, depending on the patient. Medical priority ranking was independent of the prevalence of CCs

SNX12 Role in Endosome Membrane Transport

In this paper, we investigated the role of sorting nexin 12 (SNX12) in the endocytic pathway. SNX12 is a member of the PX domain-containing sorting nexin family and shares high homology with SNX3, which plays a central role in the formation of intralumenal vesicles within multivesicular endosomes. We found that SNX12 is expressed at very low levels compared to SNX3. SNX12 is primarily associated with early endosomes and this endosomal localization depends on the binding to 3-phosphoinositides. We find that overexpression of SNX12 prevents the detachment (or maturation) of multivesicular endosomes from early endosomes. This in turn inhibits the degradative pathway from early to late endosomes/lysosomes, much like SNX3 overexpression, without affecting endocytosis, recycling and retrograde transport. In addition, while previous studies showed that Hrs knockdown prevents EGF receptor sorting into multivesicular endosomes, we find that overexpression of SNX12 restores the sorting process in an Hrs knockdown background. Altogether, our data show that despite lower expression level, SNX12 shares redundant functions with SNX3 in the biogenesis of multivesicular endosomes

The desmosomal cadherin desmoglein-3 acts as a keratinocyte anti-stress protein via suppression of p53

Desmoglein-3 (Dsg3), the Pemphigus Vulgaris (PV) antigen (PVA), plays an essential role in keratinocyte cell–cell adhesion and regulates various signaling pathways involved in the progression and metastasis of cancer where it is upregulated. We show here that expression of Dsg3 impacts on the expression and function of p53, a key transcription factor governing the responses to cellular stress. Dsg3 depletion increased p53 expression and activity, an effect enhanced by treating cells with UVB, mechanical stress and genotoxic drugs, whilst increased Dsg3 expression resulted in the opposite effects. Such a pathway in the negative regulation of p53 by Dsg3 was Dsg3 specific since neither E-cadherin nor desmoplakin knockdown caused similar effects. Analysis of Dsg3−/− mouse skin also indicated an increase of p53/p21WAF1/CIP1 and cleaved caspase-3 relative to Dsg3+/− controls. Finally, we evaluated whether this pathway was operational in the autoimmune disease PV in which Dsg3 serves as a major antigen involved in blistering pathogenesis. We uncovered increased p53 with diffuse cytoplasmic and/or nuclear staining in the oral mucosa of patients, including cells surrounding blisters and the pre-lesional regions. This finding was verified by in vitro studies where treatment of keratinocytes with PV sera, as well as a characterized pathogenic antibody specifically targeting Dsg3, evoked pronounced p53 expression and activity accompanied by disruption of cell–cell adhesion. Collectively, our findings suggThe study was supported by the Barts and The London School of Medicine and Dentistry and Guizhou Medical University, China. The animal work was supported by Deutsche Forschungsgemeinschaft (TR-SFB 156). Jutamas Uttagomol was supported by a scholarship from Naresuan University, Thailand