Topological and geometrical quantities in active cellular structures.

Topological and geometrical properties and the associated topological defects find a rapidly growing interest in studying the interplay between mechanics and the collective behavior of cells on the tissue level. We here test if well studied equilibrium laws for polydisperse passive systems such as Lewis' and Aboav-Weaire's law are applicable also for active cellular structures. Large scale simulations, which are based on a multiphase field active polar gel model, indicate that these active cellular structures follow these laws. If the system is in a state of collective motion, quantitative agreement with typical values for passive systems is also observed. If this state has not developed, quantitative differences can be found. We further compare the model with discrete modeling approaches for cellular structures and show that essential properties, such as T1 transitions and rosettes, are naturally fulfilled.

Intermittent Hypoxia Impairs Endothelial Function in Early Preatherosclerosis.

Intermittent hypoxia seems to be a major pathomechanism of obstructive sleep apnea-associated progression of atherosclerosis. The goal of the present study was to assess the influence of hypoxia on endothelial function depending on the initial stage of vasculopathy. We used 16 ApoE-/- mice were exposed to a 6-week-intermittent hypoxia either immediately (early preatherosclerosis) or after 5 weeks of high-cholesterol diet (advanced preatherosclerosis). Another 16 ApoE-/- mice under normoxia served as corresponding controls. Endothelial function was measured by an organ bath technique. Blood plasma CD31+/annexin V+ endothelial microparticles as well as sca1/flk1+ endothelial progenitor cells in blood and bone marrow were analyzed by flow cytometry. The findings were that intermittent hypoxia impaired endothelial function (56.6±6.2% of maximal phenylephrine-induced vasoconstriction vs. 35.2±4.1% in control) and integrity (increased percentage of endothelial microparticles: 0.28±0.05% vs. 0.15±0.02% in control) in early preatherosclerosis. Peripheral repair capacity expressed as the number of endothelial progenitor cells in blood was attenuated under hypoxia (2.0±0.5% vs. 5.3±1.9% in control), despite the elevated number of these cells in the bone marrow (2.0±0.4% vs. 1.1±0.2% in control). In contrast, endothelial function, as well as microparticle and endothelial progenitor cell levels were similar under hypoxia vs. control in advanced preatherosclerosis. We conclude that hypoxia aggravates endothelial dysfunction and destruction in early preatherosclerosis.

[Subtle focal diffusion abnormality in the hippocampus]. / Subtile fokale Diffusionsstörung im Hippokampus.

A 53-year-old female patient presented with sudden onset confusion and disorientation. Further neurological examination was unremarkable and the patient showed a complete recovery after several hours. A magnetic resonance imaging (MRI) examination performed 2 days later revealed a tiny focal lesion in the lateral hippocampus in the diffusion weighted images consistent with transient global amnesia.

Impact of contact inhibition on collective cell migration and proliferation.

Contact inhibition limits migration and proliferation of cells in cell colonies. We consider a multiphase field model to investigate the growth dynamics of a cell colony, composed of proliferating cells. The model takes into account the mechanism of contact inhibition of proliferation by local mechanical interactions. We compare nonmigrating and migrating cells, in order to provide a quantitative characterization of the dynamics and analyze the velocity of the colony boundary for both cases. Additionally, we measure single cell velocities, number of neighbor distributions, as well as the influence of stress and age on positions of the cells and with respect to each other.

Multiphase field models for collective cell migration.

Confluent cell monolayers and epithelia tissues show remarkable patterns and correlations in structural arrangements and actively driven collective flows. We simulate these properties using multiphase field models. The models are based on cell deformations and cell-cell interactions and we investigate the influence of microscopic details to incorporate active forces on emerging phenomena. We compare four different approaches, one in which the activity is determined by a random orientation, one where the activity is related to the deformation of the cells, and two models with subcellular details to resolve the mechanochemical interactions underlying cell migration. The models are compared with respect to generic features, such as coordination number distribution, cell shape variability, emerging nematic properties, as well as vorticity correlations and flow patterns in large confluent monolayers and confinements. All results are compared with experimental data for a large variety of cell cultures. The appearing qualitative differences of the models show the importance of microscopic details and provide a route towards predictive simulations of patterns and correlations in cell colonies.

Endostatin, the proteolytic fragment of collagen XVIII, induces vasorelaxation.

Collagen XVIII is an important component of the extracellular matrix and is expressed in basement membranes. Its degradation results in the generation of endostatin claimed to possess antiangiogenic activity. To date, only limited knowledge exists with regard to the cellular signaling of this molecule. We show in single-cell measurements using the Ca2+ indicator fura-2 acetoxy methylester (fura-2 AM) and the nitric oxide (NO) indicator 4,5-diaminofluorescein diacetate that application of endostatin (ES) (5 pmol/L, 100 ng/mL) induced Ca2+ spikes and an increase of NO production in human and murine endothelial cells. The NO response was independent of an increase in cytosolic Ca2+ and blocked by the endothelial NO synthase (eNOS) inhibitor NG-nitro-L-arginine methyl ester and by incubation with pertussis toxin known to inhibit G(i/o) proteins. The physiological relevance of this novel signaling pathway of ES was assessed with isometric force measurements in large and small arteries of mouse. Physiological concentrations of ES were found to decrease vascular tone in an endothelium-dependent manner. This occurred via an Arg-Gly-Asp (RGD) peptide-independent pathway through activation of G(i/o) proteins, phosphatidylinositol 3-kinase, Akt, and eNOS. We conclude that the proteolytic matrix fragment ES is a prominent vasorelaxing agent. Because ES is constantly released into the blood, it is a novel regulator of blood pressure and, therefore, represents an interesting pharmacological target.

[Pathobiology, pathology and genetics of pulmonary hypertension: Recommendations of the Cologne Consensus Conference 2016]. / Pathobiologie, Pathologie und Genetik der pulmonalen Hypertonie: Empfehlungen der Kölner Konsensus-Konferenz 2016.

The 2015 European Guidelines on Diagnosis and Treatment of Pulmonary Hypertension (PH) are also valid for Germany. While the guidelines contain detailed recommendations regarding clinical aspects of pulmonary arterial hypertension (PAH) and other forms of PH, they contain only a relatively short paragraph on novel findings on the pathobiology, pathology, and genetics. However, these are of great importance for our understanding of this complex disease both from a clinical and scientific point of view, and they are essential for the development of novel treatment strategies. To this end, a number of current data are relevant, prompting a detailed commentary to the guidelines, and the consideration of new scientific data. In June 2016, a Consensus Conference organized by the PH working groups of the German Society of Cardiology (DGK), the German Society of Respiratory Medicine (DGP) and the German Society of Pediatric Cardiology (DGPK) was held in Cologne, Germany. This conference aimed to solve practical and controversial issues surrounding the implementation of the European Guidelines in Germany. To this end, a number of working groups was initiated, one of which was specifically dedicated to the pathobiology, pathology and genetics of PH. This article summarizes the results and recommendations of this working group.

Developmentally controlled expression patterns of intermediate filament proteins in the cephalochordate Branchiostoma.

Expression of cytoplasmic intermediate filament (IF) proteins starts in the gastrula with three keratins (k1, Y1, D1) and protein X1. The number of IF proteins expressed increases at the neurula and early larval stages to seven and 11, respectively, and reaches 13 in the adult. Using antibodies specific for a single IF protein the expression patterns of nine of the 13 IF proteins were analyzed at different developmental stages. Keratin k1 of the larval epidermis is replaced in the juvenile by keratin E1. Protein C1 of the larval epidermis persists only weakly and only in the most ventral part of the adult. While down-regulated in the adult epidermis k1 and C1 are major proteins in the atrial epithelium which forms in the later larva. B1 is currently the only IF protein expressed in mesodermally derived tissues such as the muscle tails and some coelomic epithelia. Two-dimensional gels confirm that keratins are the major IF proteins in the nerve cord. Immunogold electronmicroscopy shows that proteins X1 and C2 are present in epidermis and nerve cord in keratin IF.

Ultrasonography and computed tomography in severe urinary tract infection.

A prospective study evaluated the utility of renal computed tomography (CT) and ultrasonography in 35 patients hospitalized for treatment of urinary tract infection. Renal computed tomograms were abnormal in 18 of 28 patients with acute pyelonephritis and three of four patients with urosepsis, showing findings consistent with pyelonephritis in 17 patients and intrarenal abscess or focal bacterial nephritis in four patients. Renal sonograms were abnormal in only eight patients, showing findings compatible with pyelonephritis in four and intrarenal abscess or focal bacterial nephritis in the other four. Flank tenderness was absent in only four patients with CT findings of pyelonephritis, of whom three were diabetic. We therefore found that (1) renal CT is a sensitive test for acute upper urinary tract infection, (2) ultrasonography detects focal bacterial nephritis and abscesses but is insensitive to uncomplicated upper urinary tract infection, and (3) painless pyelonephritis may be more common in patients with diabetes mellitus.

Does growth hormone (GH) enhance growth in GH-deficient children with myelomeningocele?

GH deficiency (GHD) in patients with myelomeningocele leads to the question of whether these disabled patients should be treated with human GH. To date, only a few short-term reports of GH therapy are available in the literature, and long-term data for final height are lacking. We report auxological and laboratory data for seven prepubertal myelomeningocele patients with proven GHD (idiopathic GHD or neurosecretory dysfunction) during GH treatment. All patients (five males and two females; median chronological age, 6.6 yr) had shunted hydrocephalus and were treated with GH (0.5 IU/kg x week; 0.15 mg/kg x week; daily sc injections) over a median period of 38 months (range, 35-49 months). GH secretion was analyzed by measurement of spontaneous overnight GH secretion and two standard stimulation tests. Auxological parameters, bone age, serum levels of insulin-like growth factor I and insulin-like growth factor-binding protein-3, and neurological and orthopedic status were documented regularly. Median growth velocity of supine length improved during treatment (at start, 3.7 cm/yr; after 36 months, 5.7 cm/yr; P < 0.05), with highest levels 6 months after the start of therapy (8.1 cm/yr). The growth velocity of arm span was greater than these values. Supine length SD score for chronological age increased from -4.71 (at start) to -3.35 (after 36 months; P = NS), length SD score for bone age increased from -2.70 to -2.23 (P = NS), and arm span SD score increased from -2.98 to -1.75 (P < 0.05). The growth velocities of length and arm span remained significantly above the pretreatment values (P < 0.05). Symptomatic tethered cord associated with progression of scoliosis developed in two of seven children. GH treatment significantly improved the growth velocities of body length and arm span. However, the increase in length SD score was not significant, whereas arm span SD scores significantly improved over the study period.

Intranasal sumatriptan for the acute treatment of migraine in children.

Sumatriptan is a highly effective treatment for migraine in adults but its efficacy in children has not been determined. Fourteen children with migraine (6.4 to 9.8 years of age; seven girls, six with aura) participated in a randomized double-blind placebo-controlled crossover study to evaluate the efficacy of sumatriptan nasal spray. After sumatriptan, 12 of 14 (versus 6 of 14 after placebo) reported a decrease in pain intensity (p = 0.031); complete headache relief was obtained in 9 of 14 after sumatriptan versus 2 of 14 after placebo (p = 0.016). Migraine-associated symptoms were also significantly reduced by sumatriptan.

Radiation therapy of optico-hypothalamic gliomas (OHG)--radiographic response, vision and late toxicity.

BACKGROUND: Management strategies for optic pathway gliomas include observation, surgery, irradiation, chemotherapy and a combination of these modalities. It has been the policy of our University Hospital to consider radiation as the standard treatment for progressive optic pathway gliomas. This report describes the clinical presentation, treatment patterns and outcome with special emphasis on the long term functional status of patients with optico-hypothalamic gliomas (OHG). PATIENTS AND METHODS: Between 1975 and 1997, 25 patients with OHG were treated by radiation therapy (RT) following surgery or biopsy. All patients received a local RT with a 0.5-1 cm margin around the lesions as depicted on CT or MRI scans. Age adjusted radiation doses ranged from 45 to 60 Gy with a single fraction size of 1.6-2 Gy. Endpoints of the study were: radiographic response, survival, progression-free survival and time to endocrinologic toxicity as well as the visual function during follow-up. The median follow-up time was 9 years (range, 1.5-23 years). RESULTS: A partial response was noted in six (24%) of the patients, 13 (52%) patients had a stable tumour throughout the observation period and six (24%) patients had a tumour progression. Overall survival and progression-free survival rates were 94 and 69% at 10 years, respectively. A significant influence on progression-free survival was noted for age at diagnosis (P=0.04) and total dose (P=0.05). Nine out of 13 (69%) patients aged below 10 years compared with 3/12 (25%) patients aged above 10 years experienced hypothalamic-pituitary deficiency (P=0.008) during follow-up. As for visual acuity, nine patients had an improvement, another 13 patients a stable situation and three patients a measurable deterioration. Visual field deficits improved in three, remained unchanged in 16 patients and worsened in only one patient. CONCLUSION: Postoperative RT with a total dose above 45 Gy should be considered as standard treatment in OHG with documented progression. Close radiographic monitoring and lifelong yearly evaluation for the need of possible hormone replacement are strongly recommended.

Adrenomedullin gene expression in human placental tIssue and leukocytes: a potential marker of severe tIssue hypoxia in neonates with birth asphyxia.

OBJECTIVE: The aim of the present study was to investigate the role of adrenomedullin (ADM) as a hypoxia-inducible marker of clinically relevant tIssue hypoxia in acute birth asphyxia of term newborn infants. METHODS: For this purpose, ADM mRNA was determined in human placental tIssue of 20 term pregnancies complicated by birth asphyxia (pH and base deficit values, clinical score). In addition, ADM mRNA was measured in leukocytes of the asphyxiated newborn infants during the first 12 h of life (n=12). Controls were available from ten healthy term pregnancies. In vitro, hypoxia-inducible expression of ADM mRNA was evaluated in human choriocarcinoma cells (BeWo) and human leukocytes exposed to hypoxia (1% O(2)) for 1-24 h. mRNA levels were measured by TaqMan real-time PCR. RESULTS: In vitro, ADM mRNA related to porphobilinogen deaminase (PBGD) mRNA levels significantly increased in response to hypoxia within a period of 4 h in leukocytes and 12 h in BeWo cells. In human placental tIssue, significantly higher levels of ADM/PBGD mRNA were present in asphyxiated newborn infants with severe hypoxic-ischemic encephalopathy (HIE) (n=5) compared with patients with mild or no HIE (n=15). Increased levels of ADM/PBGD mRNA levels were found during the first hours of life in leukocytes of neonates with severe HIE compared with controls. CONCLUSIONS: Our results indicate an upregulation of ADM gene expression in human placenta and leukocytes in clinically relevant hypoxic-ischemic birth complications and suggest ADM gene expression as a promising marker for severe complications due to perinatal asphyxia such as HIE.

Localization analysis of neuronal activities in benign rolandic epilepsy using magnetoencephalography.

Benign epilepsy of childhood with rolandic spikes (BECRS) is an electroclinical syndrome characterized by partial sensorimotor seizures with centrotemporal spikes. We report a detailed localization analysis of spontaneous magnetic brain activities in seven BECRS patients using magnetoencephalography (MEG). All patients had BECRS diagnosis with typical seizures and electroencephalographic findings and five patients had minor psychomotor deficits. MEG was recorded over both parieto-temporal regions using a 2x37-channel biomagnetic system. The collected data were digitally bandpass-filtered (2-6, 14-30, or 1-70 Hz) to analyze slow- and fast-wave magnetic activities and rolandic spikes. Slow-wave activity was increased in four hemispheres of three patients. Increased fast-wave activity was found in all five patients with minor neuropsychological deficits. The presence of increased fast-wave magnetic brain activity appeared to cause functional anomalies in the higher brain function processes. In the spike analysis, the dipoles of rolandic spikes which constantly manifested anterior positivity in direction were concentrated in the superior rolandic region in four cases and the inferior rolandic region in three cases. The localizations of increased slow- and fast-wave activities were identical with those of the spikes. The seizure profiles were frequently characterized by the spike locations. Source localizations of the focal brain activities and rolandic spikes by MEG will contribute to the different diagnosis and pathophysiological elucidation of BECRS.

Incorporation of saturated and cis- and trans-unsaturated long chain fatty acids in rat myocytes and increased susceptibility to arrhythmias.

Neonatal rat heart myocytes cultured for 3 days in fatty acid-enriched (5 X 10(5) M stearate, oleate, elaidate, linoleate, linoelaidate or arachidonate at a 3 : 1, fatty acid (FA/albumin ratio) were analyzed by high-pressure liquid chromatography (HPLC) for the FA content of their neutral lipid, glyco-cardiolipid and phospholipid fractions and were tested for their susceptibility to arrhythmias produced by hypoxic/normoxic medium changes. Increases in the relative amount of FA in the above lipid fractions were generally in the order: elaidate = linoelaidate greater than linoleate = arachidonate greater than stearate = oleate. Cell morphology was unaffected by such treatment, but the cultures were more susceptible to induced arrhythmias. Cultures enriched with trans-FA, elaidate or linoelaidate, became markedly arrhythmic; arrhythmias in stearate-enriched cultures were of short duration; whereas the other FA produced intermediate increases. Susceptibility to arrhythmias could not be correlated with polyunsaturated fatty acid (PUFA/saturated fatty acid (SATFA) ratios of FA in the phospholipid fraction.

Free radical species mediating the toxicity of ozone for cultured rat lung fibroblasts.

We have reported a model system with which to study factors influencing the toxicity of O3 for cultured rat lung cells. This continuing investigation was to determine the relative contributions of free radical species to the toxicity of O3 as measured by 51Cr release and the use of free radical scavengers. Toxicity from modes of O3 exposure favoring stable free radicals (stationary cultures or added O3-exposed medium) was prevented by the H2O2 scavenger, catalase. Toxicity produced by exposing cells to O3 through only a thin film of medium (rotated cultures) was partially prevented by either catalase or superoxide dismutase. Their combination completely prevented toxicity, suggesting that both H2O2 and O2 were major toxic species. Mannitol, an OH scavenger formed from H2O2 and O2, was partially protective with all models while the 1O2 scavengers histidine, tryptophan and xanthine were ineffective.

A quantitative metabolic inhibition test for screening toxic compounds with cultured cells.

The toxicity of substances for monolayer cultures of rat lung fibroblasts with phenol red as a pH indicator in the medium was measured by comparing the changes produced in medium color against 10 stable color standards. The toxicities of 6 concentrations each of actinomycin D, amphotericin B, chloroquine, 2-deoxyglucose, oligomycin, puromycin, and silicon dioxide were measured at 12 h and daily for 7 days on the same cultures throughout. Morphologic changes were monitored at the same times. The method, which simultaneously measures both concentration and time effects, was rapid, simple-to-perform, reproducible, low-in-cost, and quite sensitive. Its reproducibility depended on details of the cell culture methodology. The method is unsuitable for acidic or basic substances, or substances poorly-soluble in culture medium. Unless combined with morphologic evaluation, substances producing delayed toxicity may give misleading results.

Toxicity of free fatty acids for cultured rat heart muscle and endothelioid cells. I. Saturated long-chain fatty acids.

Capric (C10:0), lauric (C12:0), myristic (C14:0), palmitic (C16:0), stearic (C18:0) and arachidic (C20:0) acids were compared for their toxic effects upon cultured rat heart muscle and endothelioid cells. The free fatty acids (FFA) were found to albumin (6:1) and tested at 5 x 10(-5)M. Reduction of cell viability (51Cr release) and in situ mitochondrial and lysosomal labilization were used as indices of injury. Reduction in viability of both cell types was produced by palmitic, stearic or arachidic acids, but only after exposures of from 12 to 36 h. These FFA also produced needle-like cytoplasmic inclusions. Mitochondria and lysosomes were labilized after shorter exposures. Capric, lauric and myristic acids, were relatively non-toxic, and protected endothelioid cell lysosomes from labilization.

Toxicity of free fatty acids for cultured rat heart muscle and endothelioid cells. II. Unsaturated long-chain fatty acids.

Oleic (C18:1), linoleic (C18:2), linolenic (C18:3) and arachidonic (C20:4) acids were compared for their toxic effects upon cultured rat heart muscle and endothelioid cells. The free fatty acids (FFA) were bound to albumin (6:1) and tested at concentrations from 5 x 10(-5)M to 5 x 10(-4)M. Reduction of cell viability (51Cr release) and in situ mitochondrial and lysosomal labilization were used as indices of injury. Oleic acids was non-toxic at all times and concentrations tested while linoleic acid increased cell death only in muscle cells after 32 h. Arachidonic acid, by contrast, demonstrated significant toxicity as early as 2 h while both linolenic and arachidonic acids produced major injury at longer durations. A detergent effect was excluded as the injury mechanism because of marked differences in the toxicities of the individual FFA. The similarity in the effects of linolenic and arachidonic acids would appear to exclude prostaglandins as responsible toxic products.