An FDA-Validated, Self-Cleaning Liquid Chromatography-Mass Spectrometry System for Determining Small-Molecule Drugs and Metabolites in Organoid/Organ-on-Chip Medium.

As organoids and organ-on-chip (OoC) systems move toward preclinical and clinical applications, there is an increased need for method validation. Using a liquid chromatography-mass spectrometry (LC-MS)-based approach, we developed a method for measuring small-molecule drugs and metabolites in the cell medium directly sampled from liver organoids/OoC systems. The LC-MS setup was coupled to an automatic filtration and filter flush system with online solid-phase extraction (SPE), allowing for robust and automated sample cleanup/analysis. For the matrix, rich in, e.g., protein, salts, and amino acids, no preinjection sample preparation steps (protein precipitation, SPE, etc.) were necessary. The approach was demonstrated with tolbutamide and its liver metabolite, 4-hydroxytolbutamide (4HT). The method was validated for analysis of cell media of human stem cell-derived liver organoids cultured in static conditions and on a microfluidic platform according to Food and Drug Administration (FDA) guidelines with regards to selectivity, matrix effects, accuracy, precision, etc. The system allows for hundreds of injections without replacing chromatography hardware. In summary, drug/metabolite analysis of organoids/OoCs can be performed robustly with minimal sample preparation.

Cellulose synthesis in land plants.

All plant cells are surrounded by a cell wall that provides cohesion, protection, and a means of directional growth to plants. Cellulose microfibrils contribute the main biomechanical scaffold for most of these walls. The biosynthesis of cellulose, which typically is the most prominent constituent of the cell wall and therefore Earth's most abundant biopolymer, is finely attuned to developmental and environmental cues. Our understanding of the machinery that catalyzes and regulates cellulose biosynthesis has substantially improved due to recent technological advances in, for example, structural biology and microscopy. Here, we provide a comprehensive overview of the structure, function, and regulation of the cellulose synthesis machinery and its regulatory interactors. We aim to highlight important knowledge gaps in the field, and outline emerging approaches that promise a means to close those gaps.

Biodiscoveries within the Australian plant genus Eremophila based on international and interdisciplinary collaboration: results and perspectives on outstanding ethical dilemmas.

In a cross-continental research initiative, including researchers working in Australia and Denmark, and based on joint external funding by a 3-year grant from the Novo Nordisk Foundation, we have used DNA sequencing, extensive chemical profiling and molecular networking analyses across the entire Eremophila genus to provide new knowledge on the presence of natural products and their bioactivities using polypharmocological screens. Sesquiterpenoids, diterpenoids and dimers of branched-chain fatty acids with previously unknown chemical structures were identified. The collection of plant material from the Eremophila genus was carried out according to a 'bioprospecting agreement' with the Government of Western Australia. We recognize that several Eremophila species hold immense cultural significance to Australia's First Peoples. In spite of our best intentions to ensure that new knowledge gained about the genus Eremophila and any potential future benefits are shared in an equitable manner, in accordance with the Nagoya Protocol, we encounter serious dilemmas and potential conflicts in making benefit sharing with Australia's First Peoples a reality.

Three-dimensional ultrasound volume and conventional ultrasound diameter changes are equally good markers of endoleak in follow-up after endovascular aneurysm repair.

INTRODUCTION: The main disadvantages of computed tomography angiography (CTA) in follow-up after endovascular aneurysm repair are the risks of contrast-induced renal impairment and radiation-induced cancer. Three-dimensional ultrasound is a new technique for volume estimation of the aneurysm sac. Some studies have reported promising results. The aim of this study was to evaluate the accuracy and precision of three-dimensional ultrasound aneurysm sac-volume estimates, and to explore whether volume and/or diameter changes on ultrasound can be used as markers of endoleak. METHODS: A single-center diagnostic accuracy study was performed. A total of 92 patients planned for endovascular aneurysm repair were prospectively and consecutively enrolled (2013-2016). Aneurysm sac diameter and volume were measured using CTA, conventional ultrasound, and three-dimensional ultrasound preoperatively and 1, 6, 12, and 24 months postoperatively. Three-dimensional ultrasound was performed with a commercially available electromechanical transducer. Patients with endoleak were observed 5 years after endovascular aneurysm repair. RESULTS: A total of 79 men and 13 women were included. Mean age was 74 years (57-92 years). Median follow-up was 24 months. Endoleak cases were observed for up to 55 months. Diameter measurements on conventional ultrasound correlated well with CT diameters (r = 0.9, P < .05, n = 347), and Bland-Altman analyses showed an upper limit of agreement of +0.5 cm and a lower limit of agreement of -0.8 cm. The mean difference was -0.13 cm ± 0.36 cm. Three-dimensional ultrasound volumes had a correlation with CTA diameters of r = 0.8 (P < .05, n = 347) and with three-dimensional CT volumes of r = 0.8 (P < .05, n = 155). Receiver operating characteristic analyses showed that the diameter and volume changes that led to reintervention were most accurate at 24-month follow-up, with area-under-the-curve percentage changes of 0.98 (two-dimensional ultrasound), 0.97 (three-dimensional ultrasound), and 0.97 (two-dimensional CT). DISCUSSION: Both diameter and volume changes can be used as markers for endoleak with excellent areas under the curve on receiver operating characteristic analyses. However, three-dimensional ultrasound volumes did not add any further diagnostic information. Conventional 2D diameter measurements were as accurate as volume changes as markers of endoleak. CONCLUSIONS: Type II endoleaks can safely be followed up using a simple diameter measurement on conventional ultrasound.

Contrast-enhanced ultrasound detects type II endoleaks during follow-up for endovascular aneurysm repair.

OBJECTIVE: Repeated computed tomography angiography (CTA) can be used during follow-up visits for endovascular aneurysm repair (EVAR) but leads to accumulated radiation exposure and may cause renal impairment. Therefore, the use of contrast-enhanced ultrasound (CEUS) has increased, and its ability to detect endoleaks has been promising. The aim of this study was to investigate the diagnostic accuracy of CEUS vs CTA for endoleak detection during EVAR follow-up. METHODS: Ninety-two patients with planned EVAR for abdominal aortic aneurysm were prospectively, consecutively enrolled. In total, 233 paired CTA and CEUS procedures were performed within the same day. Follow-up visits occurred 1 month, 6 months, 12 months, and 24 months postoperatively. RESULTS: Of 48 endoleaks discovered by CTA, 39 were also detected on CEUS, giving an overall sensitivity of 81.3% and specificity of 98.9%. All undetected endoleaks were minor, without clinical importance, and occurred in patients with high body mass index. CONCLUSIONS: In this study, CEUS was accurate for detecting type II endoleaks during follow-up visits for EVAR. Sensitivity was lower in obese patients. Doppler ultrasound has low sensitivity and seems to be unsuitable for the detection of endoleaks.

Nerylneryl diphosphate is the precursor of serrulatane, viscidane and cembrane-type diterpenoids in Eremophila species.

BACKGROUND: Eremophila R.Br. (Scrophulariaceae) is a diverse genus of plants with species distributed across semi-arid and arid Australia. It is an ecologically important genus that also holds cultural significance for many Indigenous Australians who traditionally use several species as sources of medicines. Structurally unusual diterpenoids, particularly serrulatane and viscidane-types, feature prominently in the chemical profile of many species and recent studies indicate that these compounds are responsible for much of the reported bioactivity. We have investigated the biosynthesis of diterpenoids in three species: Eremophila lucida, Eremophila drummondii and Eremophila denticulata subsp. trisulcata. RESULTS: In all studied species diterpenoids were localised to the leaf surface and associated with the occurrence of glandular trichomes. Trichome-enriched transcriptome databases were generated and mined for candidate terpene synthases (TPS). Four TPSs with diterpene biosynthesis activity were identified: ElTPS31 and ElTPS3 from E. lucida were found to produce (3Z,7Z,11Z)-cembratrien-15-ol and 5-hydroxyviscidane, respectively, and EdTPS22 and EdtTPS4, from E. drummondii and E. denticulata subsp. trisulcata, respectively, were found to produce 8,9-dihydroserrulat-14-ene which readily aromatized to serrulat-14-ene. In all cases, the identified TPSs used the cisoid substrate, nerylneryl diphosphate (NNPP), to form the observed products. Subsequently, cis-prenyl transferases (CPTs) capable of making NNPP were identified in each species. CONCLUSIONS: We have elucidated two biosynthetic steps towards three of the major diterpene backbones found in this genus. Serrulatane and viscidane-type diterpenoids are promising candidates for new drug leads. The identification of an enzymatic route to their synthesis opens up the possibility of biotechnological production, making accessible a ready source of scaffolds for further modification and bioactivity testing.

Spiral Vein Graft Technique for Popliteal Artery Aneurysms.

INTRODUCTION: In patients with popliteal artery aneurysm lacking a suitable vein for bypass, prosthetic graft, or endovascular stent graft are alternative treatment options. However, durability is limited. Construction of an autologous spiral vein graft has previously been used to replace infected aortic grafts and arteriovenous fistulas. TECHNICAL SUMMARY: Five patients underwent surgery for popliteal arterial aneurysm with the spiral vein graft technique. Technical success was 100%. Operative technique and results are reported. CONCLUSION: The spiral vein graft technique can be used for popliteal artery aneurysm with good short term results, avoiding use of prosthetic grafts.

Non-curative surgery for aortoenteric fistula.

Graft infection with secondary aortic fistula is a rare complication following implantation of aortic prostheses, frequently occurring after emergency procedures and reoperations. The condition is associated with considerable morbidity and mortality. Curative treatment consists of explantation of the infected graft followed by fistula revision and implantation of a new graft in combination with antimicrobial therapy. Non-curative treatment with aortic stentgraft and long-term substitution treatment with antibiotics may be an option in cases where graft explantation is deemed too risky. We present an elderly patient with aortoenteric fistula following surgery for ruptured abdominal aortic aneurysm. Implantation of an aortic stentgraft and fistula revision was performed but the original aortic prosthesis was not explanted. The aortoenteric fistula recurred twice, but the patient has survived more than 12 years following non-curative surgery with good quality of life.

Arteriovenous fistula of the groin in a drug abuser with endocarditis.

Intravenous drug abusers commonly develop endocarditis due to injection of particulate matter that can cause endothelial damage to the valves. The frequent need to access the venous system can result in vascular traumas with potential complications including arteriovenous (AV) fistulas. Here, we present the case of an intravenous drug abuser with endocarditis and an unusually large AV fistula in the groin. The patient was successfully operated for endocarditis. However, the AV fistula was at the time not acknowledged. The combination of ileofemoral vein thrombosis and a large AV fistula led to pulmonary septic embolism and life-threating, right-sided heart failure. Computed tomography scan did not reveal the AV fistula, but suspicion was raised. Ultrasound diagnosed and revealed the magnitude of the AV fistula, and the patient was treated with a minimally invasive percutaneous technique.

Treatment of major vein injury with the hemostatic fleece TachoSil by interposing a peritoneal patch to avoid vein thrombosis: A feasibility study in pigs.

BACKGROUND: Vein lacerations in awkward locations are difficult to repair and carry high mortality. The hemostatic fleece, TachoSil, is effective in preventing intraoperative bleeding in different settings, but has not been recommended for use in large vein injury. TachoSil with a peritoneal patch interposed to avoid vein thrombosis has been reported as a method to obtain hemostasis in vein laceration, but further studies of this method are needed. MATERIALS AND METHODS: A 1.5 × 1 cm defect was created in the vena cava in five pigs. A 26 × 32 mm peritoneal patch was applied on the coagulant side of a 48 × 48 mm TachoSil sheet, and used to cover the defect. Light compression with a wet sponge was applied for 3 min. No vascular suturing was performed. RESULTS: Successful hemostasis was obtained in four out of the five pigs although the minimum TachoSil gluing zone surrounding the peritoneal patch was only 0-2 mm. The fifth pig died of hemorrhage 30 min after surgery due to a 4-mm stretch with no TachoSil gluing zone outside the peritoneal patch. At six days postoperatively the peritoneal patch was well integrated into the vein wall. After 28 days, the peritoneal patch was almost indiscernible from surrounding vein endothelium. CONCLUSIONS: Vein wall defects can be repaired using TachoSil with a peritoneal patch interposed to prevent contact between the thrombogenic TachoSil sheet and the vein lumen. An adequate TachoSil gluing zone all around the patch is essential.

Treatment of a hepatic artery aneurysm by endovascular stent-grafting.

Aneurysms of the visceral arteries are rare. Traditional treatment has been surgical or endovascular with coil embolization. Recently, however, reports on endovascular therapy with stent-grafts have been published. We report the case of a 61-year-old man who was successfully treated with a stent-graft for a symptomatic combined celiac/hepatic artery aneurysm.

[Intermittent claudication--diagnosis and treatment]. / Claudicatio intermittens--diagnostikk og behandling.

BACKGROUND: Intermittent claudication occurs in 5% of the population over 60 years, and may involve reduced walking distance, pain and a reduced quality of life. The mortality rate is 5% per year and the annual amputation rate 1%. This review article gives an update on diagnosis and medical, endovascular and surgical treatment of intermittent claudication. MATERIAL AND METHODS: The article is based on publications found on Pubmed, supplemented by clinical experience. RESULTS AND INTERPRETATION: The aims of medical, endovascular and surgical treatments are to enable the patient to walk further, obtain an improved quality of life and to live longer. Patients should first be treated medically. Endovascular treatment or open surgery, are options for patients with reduced quality of life due to limited walking distance. The treatment choice depends on the location of the arterial lesions and if the patient has any other illness.

Flow measurement before and after papaverine injection in above-knee prosthetic femoropopliteal bypass.

OBJECTIVE: To investigate the value of intraoperative blood flow measurements on early and long-term patency of above-knee prosthetic femoropopliteal bypass. METHODS: Flow was measured with a transit time flowmeter before (basal flow) and after an intragraft injection of papaverine (papaverine flow) in 87 operations (86 patients) between January 1990 and December 2001. Sixty-one grafts were of polyester, and 26 were of polytetrafluoroethylene. The operations were done under epidural anesthesia. The preoperative angiographic run-off score and clinical risk factors were recorded. Patency rates were analyzed with the product limit method and compared with the log-rank test. Variables found to be near significantly related to patency rates (P < .1) were included in a multivariate analysis performed with the Cox proportional hazard model. RESULTS: Basal flow measurements were not related to patency. The 2- and 5-year patency rates for grafts with a papaverine flow < or = 500 mL/min were 48% and 18% compared with 66% and 52% for grafts with a papaverine flow > or = 500 mL/min. These differences were statistically significant (P = .012, hazard ratio, 2.6). Two- and 5-year patency rates for smokers vs nonsmokers were 44% and 18% vs 69% and 54%. The patency rates for patients with poor vs good run-off were 42% and 27% vs 66% and 31%. Smoking (P = .008, hazard ratio, 2.75) and poor run-off score (P = .009, hazard ratio, 2.38) were found to be independent risk factors for reduced patency rates. Poor run-off score did not correlate with low values of measured basal or papaverine flow. CONCLUSIONS: Papaverine flow of < or = 500 mL/min is associated with reduced mid- and long-term patency rates. Additional antithrombotic medication and frequent follow-up for these grafts should be considered. The inferior patency rates of smokers and patients with poor run-off indicate that prosthetic bypass is less suitable for these groups of patients.

Local infections after above-knee prosthetic femoropopliteal bypass for intermittent claudication.

BACKGROUND: The use of prosthetic grafts in the treatment of intermittent claudication is still a controversy. Prosthetic bypass for this usually benign condition may in some cases lead to a graft infection. This potentially disastrous complication is difficult to manage. METHODS: One hundred forty-one consecutive operations done on 129 patients between January, 1990 and December, 2001 in a single university vascular unit have been studied. Lymphatic complications and local infections have been related to preoperative risk factors, complications, secondary procedures, and outcome. RESULTS: During a mean follow-up period of 42 months, lymph complications occurred after 18 operations, surgical site infection after 11 procedures, and graft infection after 17 operations. Eleven infected grafts were treated successfully without graft excision. Six of these grafts healed with antibiotics only. The risk of developing a local infection was significantly correlated with postoperative lymph fistula. Reoperative surgery was associated with graft infection. Graft infection caused by Staphylococcus aureus always warranted surgery, either local revision or graft excision. CONCLUSIONS: The present series had a high frequency of graft infections. Our data suggest that a selective approach should be taken towards excision of infected femoropopliteal prostheses. The need for and extent of surgery should be individualized according to the clinical presentation of the graft infection and the type of bacteria involved. We advocate a conservative attitude towards surgical treatment of intermittent claudication.

[Acute gastrointestinal bleeding caused by a ruptured splenic artery aneurysm]. / Akutt gastrointestinal blødning forårsaket av miltarterieaneurisme.

BACKGROUND: Splenic artery aneurysms are rare. Symptoms vary from none to acute abdominal pain. Gastrointestinal bleeding is a very rare symptom, but may occur in case of rupture. CASE REPORT: A 69-year-old woman was admitted for haematemesis. A ruptured splenic artery aneurysm was found. The aneurysm had ruptured into the pancreatic duct, causing gastrointestinal bleeding via the papilla of Vater. The patient's aneurysm was treated successfully with endovascular embolisation. DISCUSSION: Selective arteriography is diagnostic for splenic artery aneurysms. Endovascular treatment with embolisation of the aneurysm is the treatment of choice. When duodenoscopy is done in the case of rupture to the pancreatic duct it is mandatory to inspect the papilla of Vater for a sufficient period of time in order to see the bleeding from the papilla. Although rare, a splenic artery aneurysm should be considered in the assessment of patients with diffuse abdominal pain or gastrointestinal bleeding of unknown origin.

[Use of stents in abdominal aortic aneurysms]. / Bruk av stentgraft ved abdominale aortaaneurismer.

BACKGROUND: Endovascular treatment of aortic aneurysms has acquired a widespread application. We present the results of endovascular treatment of infrarenal, abdominal aortic aneurysms in our hospital from 1995 through 2002. MATERIAL AND METHOD: Seventy-one stent graft procedures were performed on 69 patients (64 men), mean age 72 years (range 48-96 years). Mean aneurysm diameter was 57 mm (range 35-100 mm). Sixty-nine procedures were elective and two were emergency procedures. All data were registered prospectively. RESULTS: Two procedures failed initially because of technical problems. Both patients underwent a successful procedure later. Immediate conversion to open surgery was done in one case because of a collapse of the graft into the aneurysm sac. There was no 30-day mortality for elective procedures. The conversion rate after a mean observation time of 42 months was 11%. Late complications resulted in 47 re-interventions in 29 patients, of which 96% were done in cases treated with Stentor or Vanguard prostheses. CONCLUSION: Endovascular treatment of aortic aneurysms is an alternative to open surgery. Stent graft failure can be serious and difficult to predict. This treatment should not be recommended to patients younger than 70 years and fit for open surgery.