Compartments in medulloblastoma with extensive nodularity are connected through differentiation along the granular precursor lineage

Medulloblastomas with extensive nodularity are cerebellar tumors characterized by two distinct compartments and variable disease progression. The mechanisms governing the balance between proliferation and differentiation in MBEN remain poorly understood. Here, we employ a multi-modal single cell transcriptome analysis to dissect this process. In the internodular compartment, we identify proliferating cerebellar granular neuronal precursor-like malignant cells, along with stromal, vascular, and immune cells. In contrast, the nodular compartment comprises postmitotic, neuronally differentiated malignant cells. Both compartments are connected through an intermediate cell stage resembling actively migrating CGNPs. Notably, we also discover astrocytic-like malignant cells, found in proximity to migrating and differentiated cells at the transition zone between the two compartments. Our study sheds light on the spatial tissue organization and its link to the developmental trajectory, resulting in a more benign tumor phenotype. This integrative approach holds promise to explore intercompartmental interactions in other cancers with varying histology.

Severe Dysbiosis and Specific Haemophilus and Neisseria Signatures as Hallmarks of the Oropharyngeal Microbiome in Critically Ill Coronavirus Disease 2019 (COVID-19) Patients

BACKGROUND

At the entry site of respiratory virus infections, the oropharyngeal microbiome has been proposed as a major hub integrating viral and host immune signals. Early studies suggested that infections with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are associated with changes of the upper and lower airway microbiome, and that specific microbial signatures may predict coronavirus disease 2019 (COVID-19) illness. However, the results are not conclusive, as critical illness can drastically alter a patient's microbiome through multiple confounders.

METHODS

To study oropharyngeal microbiome profiles in SARS-CoV-2 infection, clinical confounders, and prediction models in COVID-19, we performed a multicenter, cross-sectional clinical study analyzing oropharyngeal microbial metagenomes in healthy adults, patients with non-SARS-CoV-2 infections, or with mild, moderate, and severe COVID-19 (n = 322 participants).

RESULTS

In contrast to mild infections, patients admitted to a hospital with moderate or severe COVID-19 showed dysbiotic microbial configurations, which were significantly pronounced in patients treated with broad-spectrum antibiotics, receiving invasive mechanical ventilation, or when sampling was performed during prolonged hospitalization. In contrast, specimens collected early after admission allowed us to segregate microbiome features predictive of hospital COVID-19 mortality utilizing machine learning models. Taxonomic signatures were found to perform better than models utilizing clinical variables with Neisseria and Haemophilus species abundances as most important features.

CONCLUSIONS

In addition to the infection per se, several factors shape the oropharyngeal microbiome of severely affected COVID-19 patients and deserve consideration in the interpretation of the role of the microbiome in severe COVID-19. Nevertheless, we were able to extract microbial features that can help to predict clinical outcomes.

Low resting heart rates are associated with new-onset atrial fibrillation in patients with vascular disease: results of the ONTARGET/TRANSCEND studies

BACKGROUND

Elevated systolic blood pressure (SBP) and high resting heart rate (HR) are associated with cardiovascular end-points. Although the association between atrial fibrillation (AF) and SBP is well established, the relation between AF and HR remains unclear.

METHODS

In patients from the ONTARGET and TRANSCEND studies with high cardiovascular disease risk (n = 27 064), new-onset AF was evaluated in relation to mean SBP, visit-to-visit variation in SBP (SBP-CV; i.e. SD/mean × 100%), mean HR and visit-to-visit variation in HR (HR-CV).

RESULTS

Low mean HR (P < 0.0001) and high SBP (P = 0.0021) were associated with incident AF. High SBP-CV (P = 0.031) and HR-CV (P < 0.0001) were also associated with incident AF. After adjustment for confounders, SBP and SBP-CV were no longer significantly associated with AF. The detrimental effect of low HR was particularly evident in subjects who were not receiving treatment with beta-blockers (P = 0.014 for interaction between beta-blocker use and mean HR). In addition to low HR, high HR-CV and high SBP had additive effects on incident AF.

CONCLUSIONS

Low mean HR (<60 beats min(-1) ) is independently associated with incident AF, and low HR-CV and high SBP further increase the incidence of new-onset AF in patients at high risk of cardiovascular disease.

Resting heart rate is associated with renal disease outcomes in patients with vascular disease: results of the ONTARGET and TRANSCEND studies

BACKGROUND

Resting heart rate (RHR) is associated with cardiovascular disease outcomes in high-risk patients. It is not known whether RHR is predictive of renal outcomes such as albuminuria, end-stage renal disease (ESRD) or doubling of creatinine. We evaluated whether RHR could predict renal endpoints in patients at a high risk of cardiovascular disease. We also tested the effects of RHR at different levels of systolic blood pressure (SBP).

METHODS

We analysed data from 28 757 patients in the ONTARGET and TRANSCEND trials. RHR and SBP were available for a mean of 4.9 ± 0.4 visits (range 3-5) within the first 2 years of the studies. Albuminuria was determined at baseline, at 2 years and at study end.

RESULTS

Mean RHR was predictive of incident micro-albuminuria [hazard ratio (HR) for RHR ≥80 vs. <60 beats min(-1) 1.49, 95% confidence interval (CI) 1.29-1.71, P < 0.0001], incident macro-albuminuria (HR 1.84, 95% CI 1.39-2.42, P < 0.0001), doubling of creatinine (HR 1.47, 95% CI 1.00-2.17, P = 0.050) and ESRD (HR 1.78, 95% CI 1.00-3.16, P = 0.050), and the combined renal end-point (HR 1.51, 95% CI 1.32-1.74, P < 0.0001). Associations were robust at SBPs from <120 to ≥150 mmHg, with the lowest risk at a SBP of 130-140 mmHg.

CONCLUSION

Resting heart rate is a potent predictor of these renal outcomes, as well as their combination, in patients with cardiovascular disease. RHR at all SBP levels should be considered as a possible renal disease risk predictor and should be investigated as a treatment target with RHR-reducing agents.

Endovascular repair of acute uncomplicated aortic type B dissection promotes aortic remodelling: 1 year results of the ADSORB trial

OBJECTIVES

Uncomplicated acute type B aortic dissection (AD) treated conservatively has a 10% 30-day mortality and up to 25% need intervention within 4 years. In complicated AD, stent grafts have been encouraging. The aim of the present prospective randomised trial was to compare best medical treatment (BMT) with BMT and Gore TAG stent graft in patients with uncomplicated AD. The primary endpoint was a combination of incomplete/no false lumen thrombosis, aortic dilatation, or aortic rupture at 1 year.

METHODS

The AD history had to be less than 14 days, and exclusion criteria were rupture, impending rupture, malperfusion. Of the 61 patients randomised, 80% were DeBakey type IIIB.

RESULTS

Thirty-one patients were randomised to the BMT group and 30 to the BMT+TAG group. Mean age was 63 years for both groups. The left subclavian artery was completely covered in 47% and in part in 17% of the cases. During the first 30 days, no deaths occurred in either group, but there were three crossovers from the BMT to the BMT+TAG group, all due to progression of disease within 1 week. There were two withdrawals from the BMT+TAG group. At the 1-year follow up there had been another two failures in the BMT group: one malperfusion and one aneurysm formation (p = .056 for all). One death occurred in the BMT+TAG group. For the overall endpoint BMT+TAG was significantly different from BMT only (p < .001). Incomplete false lumen thrombosis, was found in 13 (43%) of the TAG+BMT group and 30 (97%) of the BMT group (p < .001). The false lumen reduced in size in the BMT+TAG group (p < .001) whereas in the BMT group it increased. The true lumen increased in the BMT+TAG (p < .001) whereas in the BMT group it remained unchanged. The overall transverse diameter was the same at the beginning and after 1 year in the BMT group (42.1 mm), but in the BMT+TAG it decreased (38.8 mm; p = .062).

CONCLUSIONS

Uncomplicated AD can be safely treated with the Gore TAG device. Remodelling with thrombosis of the false lumen and reduction of its diameter is induced by the stent graft, but long term results are needed.

Early combination therapy with telmisartan plus amlodipine for rapid achievement of blood pressure goals

BACKGROUND

Rapid and sustained blood pressure (BP) goal attainment is important to reduce cardiovascular risk. Initial use of combination therapy may improve BP goal attainment.

METHODS

The Boehringer Ingelheim trial database was searched for randomised, double-blind studies comparing telmisartan/amlodipine combination therapy with monotherapy. Eight studies were identified. Eight separate analyses were used to compare combination therapy with respective monotherapies at the earliest available time points (weeks 1, 2 and/or 4).

RESULTS

In patients initiated on combination therapy, greater systolic BP (SBP)/diastolic BP (DBP) reductions were seen with combination therapy (p < 0.0001); BP (< 140/90 mmHg), SBP (< 140 mmHg) and DBP (< 90 mmHg) goal attainment rates were significantly higher with combination therapy at all time points. In patients uncontrolled by monotherapy, greater SBP/DBP reductions were seen with combination therapy (p < 0.05 in all but one measure), and all goal attainment rates were significantly higher with combination therapy, except in one measure.

CONCLUSION

Many people can achieve their BP targets when taking a combination of telmisartan and amlodipine after failing to do so with monotherapy. Furthermore, BP targets can be achieved more rapidly using a combination of telmisartan and amlodipine as initial therapy than with either monotherapy.

[Improve your skills!: evaluation of a 2.5-day basic course in vascular surgery for surgical trainees]

BACKGROUND

The traditional surgical training in the operating room (OR) is often complemented by participation in workshops and on simulators. The foundation Vascular International offers basic courses for vascular surgery techniques with training on pulsatile circulation, lifelike anatomical models. The aim of this study was to assess the efficacy of a 2.5-day intensive course on basic skills in vascular surgery.

MATERIAL AND METHODS

A total of 24 participants (67% male with an average age of 35 years) performed a vein patch-plasty before and after the basic vascular surgery instruction course. Endpoints of the study were the time needed for suturing and the technical quality, which were evaluated by two course trainers on a scale of 0-10. Furthermore, the participants were asked to evaluate their own technical competence. The statistical analysis was carried out using MS Excel (t-test and analysis of correlation).

RESULTS

A significantly shortened time for the suturing (19.5 min versus 14.1 min, p < 0.001) and improved quality of the vein patch were found after the workshop (p < 0.05) with a high correlation between the two observers (r = 0.885). The participants also evaluated their own surgical competence better at the end of the training but there was no correlation between the self-assessment and the quality of the patch (r = 0.146 before and r = 0.109 after the workshop).

CONCLUSIONS

A significant improvement in the time needed for suturing and the quality of the vein patch-plasty was shown in this study. Further studies are necessary to demonstrate the long-term success and possible shortening of the learning curve in hospitals with professional training. With regard to the current curriculum of surgical trainees in Germany basic vascular surgery courses should be considered as a potential valuable part of the surgical common trunk.

Pocketcheck: updating the HLA class I peptide specificity roadmap

The structural determination of peptide:HLA (human leucocyte antigen) class I complexes by X-ray crystallography has provided valuable information for understanding how peptides bind to individual HLA class I molecules and how this may influence the immune response. We compared 101 crystal structures of 9-mer peptide:HLA class I complexes available in the protein data bank (PDB) by performing a contact analysis using the Contact Map Analysis webserver http://ligin.weizmann.ac.il/cma. An InterSystems Caché 'post-relational' database containing residue position, amino acid (AA) and buried surface that contact a particular peptide position was then created allowing data comparison for all the structures (Pocketcheck). The analysis illustrates that the HLA class I residues 24, 45, 63 and 67 show high contact frequencies to both the p1 and/or p2 position of bound peptides, indicating that they might influence the nature of a peptide anchor. To determine the influence of these residues we utilized soluble HLA technology and mass spectrometry to analyze peptides derived from HLA-B*44:06 since it differs from the previously described allele B*44:02 by seven AA exchanges located in the alpha 1 domain (residues 24, 32, 41, 45, 63, 67 and 80). HLA-B*44:06 features an anchor motif of P or A at p2 and Y or W at the C-terminal. Additionally B*44:06-derived peptides feature an auxiliary anchor motif at p1, comprising D or E. Our results illustrate that structural analysis can provide valuable information to understand allogenicity and provides a further step towards intelligent HLA mismatching.

Telmisartan in Migraine Prophylaxis: A Randomized, Placebo-Controlled Trial

We evaluated telmisartan 80 mg for migraine prophylaxis. Migraine patients ( n = 95) with three to seven migraine attacks in 3 months were randomized, double-blind to telmisartan or placebo. The primary end-point was the reduction in the number of migraine days (i.e. a day with ≥ 1 h of symptoms) between the 4-week baseline period and the last 4 weeks of the 12-week treatment period. A responder was recorded when there was a symptom reduction of ≥ 50% in these 4-week baseline and treatment periods. The reduction in migraine days was 1.65 with telmisartan and 1.14 with placebo ( P > 0.05). Post hoc analyses adjusting for baseline and centre showed a 38% reduction in migraine days with telmisartan vs. 15% with placebo ( P = 0.03), and a borderline significant difference in responders (40% vs. 25%, P = 0.07). The incidence of adverse events was similar between treatments. This study indicates that telmisartan might be effective in migraine prophylaxis.

Hybrid approach for arch and thoracoabdominal pathologies

The endovascular era began about 20 years ago and subsequently revolutionized vascular surgery as a less invasive treatment option, especially for high risk patients. In the late 1990s, a new hybrid approach for arch and thoracoabdominal pathologies was developed. Debranching and rerouting supra-aortic and visceral aortic branches with extra-anatomic bypass grafting was performed in order to achieve sufficient landing zones demanding for subsequent stent grafting. The initial single-center results of small series up to 20 patients were encouraging with acceptable complication rates. Hybrid arch procedures are feasible but seem to carry risks. However, the latest reports for thoracoabdominal hybrid procedures demand a word of caution due to high morbidity rates. The hybrid approach may be reserved for a selected comorbid patient cohort, which is regarded unfit for open reconstruction.

Impact of angiotensin receptor blockade in combination with hydrochlorothiazide 25 mg in 2121 patients with stage 1-2 hypertension

The antihypertensive effects of telmisartan 80 mg versus valsartan 160 mg, both combined with hydrochlorothiazide (HCTZ) 25 mg, were assessed in a pooled analysis from two large trials with identical study designs in patients with stage 1-2 hypertension. The trials were double-blind with a 4:4:1 randomization scheme to compare once-daily telmisartan 80 mg and HCTZ 25 mg versus once-daily valsartan 160 mg and HCTZ 25 mg versus once-daily placebo on reductions in clinic blood pressure (BP). The primary end point was changes from baseline in BP at the end of 8 weeks. In total, 2121 patients were randomized (telmisartan-HCTZ, 942, valsartan-HCTZ, 952, and placebo, 227) and had baseline seated BPs of 154/102 and 155/102 mm Hg in the two studies, respectively. Changes from baseline in BP after administration of telmisartan-HCTZ (-24.5/-18.0 mm Hg) were significantly greater than for both placebo (-4.1/-6.5 mm Hg) and valsartan-HCTZ (-22.3/-16.8 mm Hg) (versus placebo, P<0.0001 for systolic and diastolic BP; versus valsartan-HCTZ, P=0.0004 for systolic BP and P=0.0019 for diastolic BP). Adverse event rates were higher in the placebo group than in the active treatment groups (placebo, 41%, telmisartan-HCTZ, 30%, and valsartan-HCTZ, 30%, P<0.05). These data confirm that telmisartan-HCTZ at doses of 80/25 mg lowered systolic and diastolic BP to a greater extent than valsartan-HCTZ at doses of 160/25 mg in stage 1-2 hypertension. The magnitude of the BP-lowering effect provides support for the use of angiotensin receptor blockers with higher doses of a thiazide diuretic (25 mg) to improve hypertension control.

Intracranial dissection during carotid endarterectomy treated by carotid stenting

Intracranial dissection of the internal carotid artery after carotid endarterectomy (CEA) is a serious complication with a potentially fatal outcome. We report on a 67 male with a symptomatic high grad stenosis of the internal carotid artery. Intraoperative completion angiography showed a thrombotic occlusion and the internal carotid artery (ICA) was resected with interposition of a Dacron graft. Completion angiography then revealed a dissection of the petreous ICA, which was corrected by insertion of a coronary artery stent.Stenting of the ICA is a useful tool to restore cerebral perfusion without time delay and completion imaging is extremely helpful for early detection of dissection during CEA.

Magnitude of the early morning blood pressure surge in untreated hypertensive patients: a pooled analysis

OBJECTIVES

A post hoc analysis was performed to assess the magnitude of the early morning blood pressure surge (EMBPS), which is associated with peak cardiovascular risk, in untreated hypertensive patients enrolled in two sister studies (Prospective, Randomised Investigation of the Safety and efficacy of MICARDIS vs. ramipril using ambulatory blood pressure monitoring I and II) with identical design.

METHODS

In adults with a mild-to-moderate primary hypertension and no significant comorbidities, 24-h ambulatory blood pressure monitoring was conducted after a 2- to 4-week placebo run-in period and before treatment initiation. Individual blood pressure measurements at 20-min intervals were analysed.

RESULTS

In 1419 hypertensive patients with normal sleeping times, blood pressure displayed a typical circadian rhythm, with a mean EMBPS of 29/24 mmHg. An EMBPS of >or= 25 mmHg was observed in around 60% of patients. The surge was significantly increased with smoking, alcohol consumption, longer sleep, later waking times, and increased blood pressure variability during waking and sleeping. The magnitude of the EMBPS was significantly reduced in Black vs. White patients. The surge was not affected by gender, body mass index or duration of hypertension. Further analysis showed that ethnicity, alcohol consumption and smoking were all found to have a significant impact on surge around waking and age, sleep duration and sleep blood pressure variability were all found to have an effect on the prewake surge.

CONCLUSIONS

In untreated hypertensive patients, the magnitude of the EMBPS is significant when compared with the 24-h mean and is affected by individual patient characteristics. In light of these findings, physicians should understand the importance of 24-h blood pressure control and the modification of certain lifestyle factors as ways of reducing the EMBPS.

Effects of the angiotensin-receptor blocker telmisartan on cardiovascular events in high-risk patients intolerant to angiotensin-converting enzyme inhibitors: a randomised controlled trial

BACKGROUND

Angiotensin-converting enzyme (ACE) inhibitors reduce major cardiovascular events, but are not tolerated by about 20% of patients. We therefore assessed whether the angiotensin-receptor blocker telmisartan would be effective in patients intolerant to ACE inhibitors with cardiovascular disease or diabetes with end-organ damage.

METHODS

After a 3-week run-in period, 5926 patients, many of whom were receiving concomitant proven therapies, were randomised to receive telmisartan 80 mg/day (n=2954) or placebo (n=2972) by use of a central automated randomisation system. Randomisation was stratified by hospital. The primary outcome was the composite of cardiovascular death, myocardial infarction, stroke, or hospitalisation for heart failure. Analyses were done by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00153101.

FINDINGS

The median duration of follow-up was 56 (IQR 51-64) months. All randomised patients were included in the efficacy analyses. Mean blood pressure was lower in the telmisartan group than in the placebo group throughout the study (weighted mean difference between groups 4.0/2.2 [SD 19.6/12.0] mm Hg). 465 (15.7%) patients experienced the primary outcome in the telmisartan group compared with 504 (17.0%) in the placebo group (hazard ratio 0.92, 95% CI 0.81-1.05, p=0.216). One of the secondary outcomes-a composite of cardiovascular death, myocardial infarction, or stroke-occurred in 384 (13.0%) patients on telmisartan compared with 440 (14.8%) on placebo (0.87, 0.76-1.00, p=0.048 unadjusted; p=0.068 after adjustment for multiplicity of comparisons and overlap with primary outcome). 894 (30.3%) patients receiving telmisartan were hospitalised for a cardiovascular reason, compared with 980 (33.0%) on placebo (relative risk 0.92, 95% CI 0.85-0.99; p=0.025). Fewer patients permanently discontinued study medication in the telmisartan group than in the placebo group (639 [21.6%] vs 705 [23.8%]; p=0.055); the most common reason for permanent discontinuation was hypotensive symptoms (29 [0.98%] in the telmisartan group vs 16 [0.54%] in the placebo group).

INTERPRETATION

Telmisartan was well tolerated in patients unable to tolerate ACE inhibitors. Although the drug had no significant effect on the primary outcome of this study, which included hospitalisations for heart failure, it modestly reduced the risk of the composite outcome of cardiovascular death, myocardial infarction, or stroke.

FUNDING

Boehringer Ingelheim.

Imaging modalities for the thoracic aorta

Almost 50 years after its introduction intra-arterial digital subtraction angiography (DSA) has been passed as the gold standard for diagnostic imaging of the aorta. Today's performance of multi-detector-row computed tomography angiography (CTA) as well as magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) offer remarkable improvements in the field of diagnostic cardiovascular imaging. The racy developments not only concerning image acquisition but also image postprocessing offer a multidimensional approach to assess anatomy and pathology of individual patients in a few minutes. Four-dimensional visualization assists us to select the ''adequate'' patient, quantify vascular and adjacent geometries, and select the appropriate device to realize even complex thoracic endovascular aortic reconstructions (TEVAR). There is still a discrepancy between perioperative and intraoperative imaging--but new technologies made also some progress in this field. Lifelong imaging surveillance of TEVAR and bypasses is still a critical component of patient care and requires comparable imaging and postprocessing capabilities as for the preoperative setting. Although is the most commonly used examination for imaging surveillance, MRA, chest x-ray and DSA all have their role in determining complications and their management.

Abdominoplasty as an adjunct to the management of peri-Caesarian section necrotising fasciitis

Necrotising fasciitis is a rare but potentially lethal condition, often requiring extensive soft tissue debridement and complex reconstructive surgery. The disease has been noted to complicate Caesarian section wounds, and our department has recently managed three such patients. They all required extensive abdominal wall debridements which would traditionally be closed initially by split skin grafting. We report on the clinical course of three patients, two of whom had their defects closed successfully by abdominoplasty without recourse to initial skin grafting.

[Leiomyosarcoma of the inferior vena cava]

Leiomyosarcomas of the inferior vena cava are rare and the clinical symptoms unspecific. We report a case of leiomyosarcoma of the inferior vena cava in an 82-year-old woman presenting with weight loss and abdominal pain. Following elaborate preoperative examinations, surgical resection was performed and the inferior vena cava was reconstructed. Clinical signs, diagnosis, therapy, and prognosis are discussed.