Molecular signatures of cortical expansion in the human fetal brain.

The third trimester of human gestation is characterised by rapid increases in brain volume and cortical surface area. A growing catalogue of cells in the prenatal brain has revealed remarkable molecular diversity across cortical areas.1,2 Despite this, little is known about how this translates into the patterns of differential cortical expansion observed in humans during the latter stages of gestation. Here we present a new resource, µBrain, to facilitate knowledge translation between molecular and anatomical descriptions of the prenatal developing brain. Built using generative artificial intelligence, µBrain is a three-dimensional cellular-resolution digital atlas combining publicly-available serial sections of the postmortem human brain at 21 weeks gestation3 with bulk tissue microarray data, sampled across 29 cortical regions and 5 transient tissue zones.4 Using µBrain, we evaluate the molecular signatures of preferentially-expanded cortical regions during human gestation, quantified in utero using magnetic resonance imaging (MRI). We find that differences in the rates of expansion across cortical areas during gestation respect anatomical and evolutionary boundaries between cortical types5 and are founded upon extended periods of upper-layer cortical neuron migration that continue beyond mid-gestation. We identify a set of genes that are upregulated from mid-gestation and highly expressed in rapidly expanding neocortex, which are implicated in genetic disorders with cognitive sequelae. Our findings demonstrate a spatial coupling between areal differences in the timing of neurogenesis and rates of expansion across the neocortical sheet during the prenatal epoch. The µBrain atlas is available from: https://garedaba.github.io/micro-brain/ and provides a new tool to comprehensively map early brain development across domains, model systems and resolution scales.

αvß8 integrin-expression by BATF3-dependent dendritic cells facilitates early IgA responses to Rotavirus.

Secretory intestinal IgA can protect from re-infection with rotavirus (RV), but very little is known about the mechanisms that induce IgA production during intestinal virus infections. Classical dendritic cells (cDCs) in the intestine can facilitate both T cell-dependent and -independent secretory IgA. Here, we show that BATF3-dependent cDC1, but not cDC2, are critical for the optimal induction of RV-specific IgA responses in the mesenteric lymph nodes. This depends on the selective expression of the TGFß-activating integrin αvß8 by cDC1. In contrast, αvß8 on cDC1 is dispensible for steady state immune homeostasis. Given that cDC2 are crucial in driving IgA during steady state but are dispensable for RV-specific IgA responses, we propose that the capacity of DC subsets to induce intestinal IgA responses reflects the context, as opposed to an intrinsic property of individual DC subsets.

Respiration resolved imaging with continuous stable state 2D acquisition using linear frequency SWEEP.

PURPOSE: To investigate the potential of continuous radiofrequency (RF) shifting (SWEEP) as a technique for creating densely sampled data while maintaining a stable signal state for dynamic imaging. METHODS: We present a method where a continuous stable state of magnetization is swept smoothly across the anatomy of interest, creating an efficient approach to dense multiple 2D slice imaging. This is achieved by introducing a linear frequency offset to successive RF pulses shifting the excited slice by a fraction of the slice thickness with each successive repeat times (TR). Simulations and in vivo imaging were performed to assess how this affects the measured signal. Free breathing, respiration resolved 4D volumes in fetal/placental imaging is explored as potential application of this method. RESULTS: The SWEEP method maintained a stable signal state over a full acquisition reducing artifacts from unstable magnetization. Simulations demonstrated that the effects of SWEEP on slice profiles was of the same order as that produced by physiological motion observed with conventional methods. Respiration resolved 4D data acquired with this method shows reduced respiration artifacts and resilience to non-rigid and non-cyclic motion. CONCLUSIONS: The SWEEP method is presented as a technique for improved acquisition efficiency of densely sampled short-TR 2D sequences. Using conventional slice excitation the number of RF pulses required to enter a true steady state is excessively high when using short-TR 2D acquisitions, SWEEP circumvents this limitation by creating a stable signal state that is preserved between slices.

The use of antenatal fetal magnetic resonance imaging in the assessment of patients at high risk of preterm birth.

Preterm birth, defined as birth occurring prior to 37 weeks gestation is a common obstetric complication affecting 8% of pregnancies and is associated with significant morbidity and mortality. Infection/inflammation has been implicated in both the aetiology of preterm birth itself and associated neonatal pulmonary and neurological morbidity. Treatment options are currently limited to prolongation of the pregnancy using cervical cerclage, pessaries or progesterone or administration of drugs including steroids to promote lung maturity and neuroprotective agents such as magnesium sulphate, the timing of which are highly critical. Although delivery is expedited in cases of overt infection, decisions regarding timing and mode of delivery in subclinical infection are not clear-cut. This review aims to explore the use of magnetic resonance imaging (MRI) in the antenatal assessment of pregnancies at high risk of preterm birth and its potential to guide management decisions in the future.

Nanoscale adhesion forces between enamel pellicle proteins and hydroxyapatite.

The acquired enamel pellicle (AEP) is important for minimizing the abrasion caused by parafunctional conditions as they occur, for instance, during bruxism. It is a remarkable feature of the AEP that a protein/peptide film can provide enough protection in normofunction to prevent teeth from abrasion and wear. Despite its obvious critical role in the protection of tooth surfaces, the essential adhesion features of AEP proteins on the enamel surface are poorly characterized. The objective of this study was to measure the adhesion force between histatin 5, a primary AEP component, and hydroxyapatite (HA) surfaces. Both biotinylated histatin 5 and biotinylated human serum albumin were allowed to adsorb to streptavidin-coated silica microspheres attached to atomic force microscope (AFM) cantilevers. A multimode AFM with a Nanoscope IIIa controller was used to measure the adhesion force between protein-functionalized silica microspheres attached to cantilever tips and the HA surface. The imaging was performed in tapping mode with a Si3N4 AFM cantilever, while the adhesion forces were measured in AFM contact mode. A collection of force-distance curves (~3,000/replicate) was obtained to generate histograms from which the adhesion forces between histatin 5 or albumin and the HA surface were measured. We found that histatin 5 exhibited stronger adhesion forces (90% >1.830 nN) to the HA surface than did albumin (90% > 0.282 nN). This study presents an objective approach to adhesion force measurements between histatin 5 and HA, and provides the experimental basis for measuring the same parameters for other AEP constituents. Such knowledge will help in the design of synthetic proteins and peptides with preventive and therapeutic benefits for tooth enamel.

[Oesophageal GIST at the left tracheobronchial angle: resection with right-sided VATS]. / GIST des Ösophagus im linken tracheobronchialen Winkel: Resektion mittels rechtsthorakaler VATS.

OBJECTIVE: The vast majority of submucosal oesophageal tumours are leiomyomas. Gastrointestinal stromal tumours (GIST) account for only one percent of all gastrointestinal malignancies, whereby an oesophageal location represents a medical rarity. Although surgical resection is the gold standard, the optimal procedure remains a matter of debate. Conventional oesophageal resection is the most common therapeutic choice to ensure complete removal with an appropriate safety margin and avoid dissemination of neoplastic cells. Anyhow, occasional case reports about enucleation of oesophageal GIST have been published. This video paper for the first time describes the use of right-sided video-assisted thoracoscopic surgery (VATS) as a technique to enucleate an oesophageal GIST within the left tracheobronchial angle. INDICATION: A 68-year-old male patient was evaluated for recurrent haemoptysis and dysphagia and diagnosed with a 1.4 cm sized oesophageal tumour at the left tracheobronchial angle. CT scan showed a submucosal location without signs of invasive growth. After conducting endosonography we suspected a leiomyoma and performed minimally invasive enucleation with right-sided VATS. METHOD: Employing independent lung ventilation the patient was put into a left lateral position. Four trocars were applied. After incision of the mediastinal pleura the tumour was localised with intraoperative gastroscopy and diaphanoscopy. By mobilisation of the oesophagus and transection of the azygous vein it was possible to bluntly dissect the mass from surrounding oesophageal muscular fibres and safely extract it with a specimen bag. After removal of the thoracic drainage on the first postoperative day the patient was discharged the day after. The further course was uneventful. Histological work-up showed a GIST pT1cN0M0 R0 with a Ki-67 index less than 1 % (UICC I). After 10 months of follow-up the patient is recurrence-free and shows no symptoms. CONCLUSION: Enucleation of a locally limited oesophageal GIST by right-sided VATS is a feasible and safe surgical procedure with dramatically reduced invasiveness compared to conventional open oesophageal resections.

Pharmacological characterization of the first potent and selective antagonist at the cysteinyl leukotriene 2 (CysLT(2)) receptor.

BACKGROUND AND PURPOSE: Cysteinyl leukotrienes (CysLTs) have been implicated in the pathophysiology of inflammatory and cardiovascular disorders. Their actions are mediated by CysLT(1) and CysLT(2) receptors. Here we report the discovery of 3-({[(1S,3S)-3-carboxycyclohexyl]amino}carbonyl)-4-(3-{4-[4-(cyclo-hexyloxy)butoxy]phenyl}propoxy) benzoic acid (HAMI3379), the first potent and selective CysLT(2) receptor antagonist. EXPERIMENTAL APPROACH: Pharmacological characterization of HAMI3379 was performed using stably transfected CysLT(1) and CysLT(2) receptor cell lines, and isolated, Langendorff-perfused, guinea pig hearts. KEY RESULTS: In a CysLT(2) receptor reporter cell line, HAMI3379 antagonized leukotriene D(4)- (LTD(4)-) and leukotriene C(4)- (LTC(4)-) induced intracellular calcium mobilization with IC(50) values of 3.8 nM and 4.4 nM respectively. In contrast, HAMI3379 exhibited very low potency on a recombinant CysLT(1) receptor cell line (IC(50) > 10 000 nM). In addition, HAMI3379 did not exhibit any agonistic activity on both CysLT receptor cell lines. In binding studies using membranes from the CysLT(2) and CysLT(1) receptor cell lines, HAMI3379 inhibited [(3)H]-LTD(4) binding with IC(50) values of 38 nM and >10 000 nM respectively. In isolated Langendorff-perfused guinea pig hearts HAMI3379 concentration-dependently inhibited and reversed the LTC(4)-induced perfusion pressure increase and contractility decrease. The selective CysLT(1) receptor antagonist zafirlukast was found to be inactive in this experimental setting. CONCLUSIONS AND IMPLICATIONS: HAMI3379 was identified as a potent and selective CysLT(2) receptor antagonist, which was devoid of CysLT receptor agonism. Using this compound, we showed that the cardiac effects of CysLTs are predominantly mediated by the CysLT(2) receptor.

Reduced frontal white matter volume in long-term childhood leukemia survivors: a voxel-based morphometry study.

BACKGROUND AND PURPOSE: To our knowledge, no published studies have examined whole-brain regional differences to identify more discrete volumetric changes in the brains of childhood leukemia survivors. We used voxel-based morphometry (VBM) to examine regional gray and white matter differences in a group of long-term survivors of acute lymphoblastic leukemia (ALL) compared with a group of healthy controls. Differences in regional white matter volume were expected, given previous reports of white matter changes during treatment for ALL and reduced brain white matter volumes in long-term survivors. Follow-up analyses examined the relationship of regional brain volumes to cognitive function. MATERIALS AND METHODS: We compared 9 long-term survivors of ALL with 14 healthy controls. Survivors of ALL were treated with systemic and intrathecal chemotherapy only. T1-weighted axial 3D spoiled gradient high-resolution images collected on a 1.5T MR imaging scanner were used for the VBM analysis. Neuropsychological evaluations were conducted within 2 months of the MR imaging to assess cognitive function. RESULTS: VBM analysis revealed 2 specific regions of reduced white matter in the right frontal lobes of survivors of ALL compared with healthy controls. Survivors of ALL had lower performances on tests of attention, visual-constructional skills, mental flexibility, and math achievement compared with healthy individuals. Decreased performance on neuropsychological measures was associated with decreased regional white matter volumes. No differences were found between the groups with respect to gray matter regions. CONCLUSION: These findings are consistent with previous literature describing the long-term cognitive, academic, and imaging findings of survivors of ALL and suggest that right frontal white matter is particularly vulnerable to disruption following intensive chemotherapy for ALL. Future studies should focus on further clarifying the white matter changes observed.

Cardiovascular effects of a novel potent and highly selective azaindole-based inhibitor of Rho-kinase.

BACKGROUND AND PURPOSE: Rho-kinase (ROCK) has been implicated in the pathophysiology of altered vasoregulation leading to hypertension. Here we describe the pharmacological characterization of a potent, highly selective and orally active ROCK inhibitor, the derivative of a class of azaindoles, azaindole 1 (6-chloro-N4-{3,5-difluoro-4-[(3-methyl-1H-pyrrolo[2,3-b]pyridin-4-yl)oxy]-phenyl}pyrimidine-2,4-diamine). EXPERIMENTAL APPROACH: Pharmacological characterization of azaindole 1 was performed with human recombinant ROCK in vitro. Vasodilator activity was determined using isolated vessels in vitro and different animal models in vivo. KEY RESULTS: This compound inhibited the ROCK-1 and ROCK-2 isoenzymes with IC50 s of 0.6 and 1.1 nM in an ATP-competitive manner. Although ATP-competitive, azaindole 1 was inactive against 89 kinases (IC50>10 microM) and showed only weak activity against an additional 21 different kinases (IC50=1-10 microM). Only the kinases TRK und FLT3 were inhibited by azaindole 1 in the sub-micromolar range, albeit with IC50 values of 252 and 303 nM, respectively. In vivo, azaindole 1 lowered blood pressure dose-dependently after i.v. administration in anaesthetized normotensive rats. In conscious normotensive and spontaneously hypertensive rats azaindole 1 induced a dose-dependent decrease in blood pressure after oral administration without inducing a significant reflex increase in heart rate. In anaesthetized dogs, azaindole 1 induced vasodilatation with a moderately elevated heart rate. CONCLUSIONS AND IMPLICATIONS: Azaindole 1 is representative of a new class of selective and potent ROCK inhibitors and is a valuable tool for the elucidation of the role of ROCK in the cardiovascular system.

PDE5 inhibitors beyond erectile dysfunction.

The phosphodiesterase type-5 (PDE5) inhibitors sildenafil, vardenafil and tadalafil are widely used first-line therapy for erectile dysfunction (ED). Since the advent of sildenafil in 1998, more than 40 million men worldwide have been successfully treated with these compounds. The safety and high tolerability of PDE5 inhibitors make them an attractive tool to investigate further physiological functions of PDE5, for example the modulation of intracellular cyclic GMP (cGMP) pools. As cGMP is a key component of intracellular signaling this may provide novel therapeutic opportunities beyond ED even for indications in which chronic administration is necessary. The approval of sildenafil for the treatment of pulmonary hypertension in 2005 was a notable success in this area of research. A number of other potential new indications are currently in various phases of preclinical research and development. In recent years, extensive but very heterogeneous information has been published in this field. The aim of this review is to summarize existing preclinical and clinical knowledge and critically discuss the evidence to support potential future indications for PDE5 inhibitors.

Flexible versus rigid endoscopy for treatment of foreign body impaction in the esophagus.

BACKGROUND: The use of either flexible endoscopy (FE) or rigid endoscopy (RE) for removal of ingested foreign bodies (FBs) impacted in the esophagus is still discussed controversially. METHODS: We report a consecutive series of 139 patients with FB impaction in the esophagus. During a 6-year period, 69 men and 70 women (median age, 64 [0.7-97] years) requiring removal of an impacted FB underwent either RE (n = 63) in the Otolaryngology Department of our hospital or FE (n = 76) in the Surgical Endoscopy Unit. RESULTS: Foreign body removal was equally effective with FE (success rate 93.4%) and RE (95.2%, p = n.s.). The cases in which foreign body removal failed (5 FE cases [6.6%] and 3 RE cases [4.8%]) were all subsequently successfully managed with "conversion" and use of the other technique. No severe complications occurred when FB removal was attempted with FE (0 of 76 cases; 0.0%), whereas RE was associated with esophageal rupture requiring immediate surgical intervention in 2 of 63 cases (3.2%; p < 0.002). Patient comfort differed significantly between the two procedures (p < 0.0001); RE was always performed under general anesthesia (100.0%), whereas only a minority of patients undergoing FE required general anesthesia (13.0%; p < 0.0001) or mild analgosedation (20.0%). The better patient comfort with FE was also reflected in a significantly lower rate of dysphagia (15%) compared to RE (48%; p < 0.0001). Rigid endoscopy was more frequently used in removal of FBs of the upper esophagus (p < 0.0001), whereas FE was the predominate approach to FBs in the lower esophagus (p < 0.0001). CONCLUSIONS: A tailored approach to treatment of FB impaction is recommended. Because of the lower rate of severe complications, better patient comfort with a lower rate of dysphagia, and lack of requirement for general anesthesia, FE should be the "first line" approach to FBs, although RE has its place as the "second line" therapy.

The management of life-threatening haemorrhage following blunt facial trauma.

Life-threatening bleeding is uncommon following blunt facial trauma. There have been few reports in the literature describing its optimal management and a clear approach to treatment is yet to be defined. Reported strategies for control of facial haemorrhage include oro-nasal packing, external carotid artery ligation, transantral ligation of the internal maxillary artery, maxillary reduction and angiographic embolisation. Advances in angiography and selective vessel embolisation have made this the treatment of choice in cases of bleeding following penetrating facial injury. Its use in the management of bleeding following blunt facial trauma is unclear. The combined experience of the facial trauma teams at Harborview Hospital, Seattle, USA and Liverpool Hospital, Sydney, Australia yielded four cases of severe life-threatening haemorrhage following blunt trauma that underwent angiography. The roles of various management strategies were evaluated to generate a preferred management pathway in treating severe bleeding following blunt facial trauma.

Application of current knowledge to the management of bleeding events during immune tolerance induction.

The development of inhibitors to factor VIII is the most serious adverse event associated with the treatment of haemophilia A, predisposing patients to uncontrollable haemorrhage, disability and premature death. Eradication of inhibitors via immune tolerance induction (ITI) is effective in the majority of patients, but may require months to years to achieve success. In the interim, the treatment and prevention of acute bleeding episodes are primary foci of care. Regrettably, there is a paucity of information regarding management of bleeding episodes in inhibitor patients undergoing tolerization. Until specific data from ongoing clinical trials are available to provide more guidance in this patient group, it is reasonable and useful to rely on the broader base of medical literature pertaining to patients not being tolerized to deduce strategies for controlling acute and perioperative bleeding episodes in inhibitor patients during ITI.

Car-parrinello molecular dynamics simulation of liquid formic acid.

First-principles molecular dynamics has been used to investigate the structural, vibrational, and energetic properties of formic acid, formic acid-formate anion dimers, and liquid formic acid in a periodically repeated box with 32 formic acid molecules. We found that in liquid formic acid the hydrogen-bonded clusters mainly consist of linear branching chains. From our simulation, we got good agreement with the available structural and dynamical data. We also studied the proton transfer in the cis-formic acid-formate anion dimer, and we showed that this proton transfer does not have any potential barrier. The hydrogen bonding statistics as well as the mean lifetime of the hydrogen bonds are analyzed.

Characterization of the structure and properties of authentic and counterfeit polypropylene surgical meshes.

A counterfeit version of the Ethicon Prolene polypropylene mesh was distributed to hospitals and clinics and unintentionally implanted into patients undergoing tension-free hernia repair. On December 19, 2003, the Food and Drug Administration (FDA) issued a public health web notification indicating that the counterfeit mesh was not sterile or safe to use. To develop safety recommendations for patients with the counterfeit mesh implant, we compared the counterfeit's structural, physical, chemical and mechanical properties with polypropylene meshes previously cleared by FDA. The mesh fibers for all the products tested were found to have similar chemical and physical properties. The mechanical properties were directly related to the knitted structure (loop size, repeat distance, fabric tightness) and the porosity. Extracts from the counterfeit mesh passed cytotoxicity screening tests. The FDA further recommended that if the mesh had been inadvertently implanted, then those patients should be monitored as would be the practice for any patient with an implanted surgical mesh.

Atomic force microscopy investigation of the dependence of cellular elastic moduli on glutaraldehyde fixation.

Summary The atomic force microscope (AFM) has provided nanoscale analyses of surfaces of cells that exhibit strong adhesive and cell spreading properties. However, it is frequently reported that prior fixation is required for reliable imaging of cells with lower adhesive properties. In the present study, the AFM is used to assess the effects of fixation by glutaraldehyde on the elastic modulus of a human rhabdomyosarcoma transfectant cell line RDX2C2. Our results show a sharp increase in the elastic modulus for even mild fixation (0.5% glutaraldehyde for 60 s), accompanied by a dramatic improvement in imaging reproducibility. An even larger increase is seen in NIH-3T3 mouse fibroblasts, although in that case fixation is not typically necessary for successful imaging. In addition, our results suggest that treatment with glutaraldehyde restricts the content of the resulting images to features nearer to the cell surface.

Distribution of bisphenol A in the neuroendocrine organs of female rats.

The distribution of 14C-bisphenol A (BPA) in plasma and neuroendocrine organs was determined in Fischer 344 female rats following three oral doses (0.1, 10 or 100mg/kg). Plasma and tissue maximum concentrations (Cmax) were reached within 15-30 min of dosing. Plasma areas-under-the-curve (AUC) ranged from 0.06 to 53.9 microg-h/mL. The AUCs of the pituitary gland and uterus/gonads were 16-21% higher than that of plasma. The AUCs of hypothalamus and the rest of the brain were 43.7% and 77% of the plasma AUCs, respectively. In the brain tissue, the exposure increased linearly with the oral dose, as the dose was increased from 0.1 to 10 and 100 mg/kg; the exposure in the brain relative to the plasma increased by factors of 1, 1.19 and 1.24. This indicates that the brain barrier systems do not limit the access of the lipophilic BPA to the brain. The increases of the uterus/gonads relative to the plasma were 1, 1.07 and 1.04. Tissue partitioning was also examined in vitro by the uptake of 14C-BPA. The BPA tissue/blood partition coefficients were as follows: heart, 7.5; liver, 6.1; kidney, 6.4; fat, 3.6; muscle, 2.6; breast, 3.6; ovaries, 9.1; uterus, 5.9; stomach, 5.1; and small intestine, 6.7. The tissue/cerebrospinal fluid partition coefficients were as follows: pituitary gland, 12.8; brain stem, 6.1; cerebellum, 6.4; hippocampus, 7.1; hypothalamus, 6.1; frontal cortex, 4.9; and caudate nucleus, 6.8.