Modeling Stem/Progenitor Cell-Induced Neovascularization and\ud Oxygenation around Solid Implants

Tissue engineering constructs and other solid implants with biomedical applications, such as drug delivery devices or bioartificial organs, need oxygen (O2) to function properly. To understand better the vascular integration of such devices, we recently developed a novel model sensor containing O2-sensitive crystals, consisting of a polymeric capsule limited by a nano-porous filter. The sensor was implanted in mice with hydrogel alone (control) or hydrogel embedded with mouse CD117/c-kit+ bone marrow progenitor cells (BMPC) in order to stimulate peri-implant neovascularization. The sensor provided local partial O2 pressure (pO2) using non-invasive electron paramagnetic resonance (EPR) signal measurements. A consistently higher level of per-implant oxygenation was observed in the cell-treatment case as compared to the control over a 10-week period. In order to provide a mechanistic explanation of these experimental observations, we present in this paper a mathematical model, formulated as a system of coupled partial differential equations, that simulates peri-implant vascularization. In the control case, vascularization is considered to be the result of a Foreign Body Reaction (FBR) while in the cell-treatment case, adipogenesis in response to paracrine stimuli produced by the stem cells is assumed to induce neovascularization. The model is validated by fitting numerical predictions of local pO2 to measurements from the implanted sensor. The model is then used to investigate further the potential for using stem cell treatment to enhance the vascular integration of biomedical implants. We thus demonstrate how mathematical modeling combined with experimentation can be used to infer how vasculature develops around biomedical implants in control and stem celltreated cases

Some aspects of the wind in the northern area of the depression of Transsylvania

Összefoglalás - A jelen tanulmány az Erdélyi Medence északi részén előforduló talajmenti és magaslati szél egyes vonásait mutatja be. A szél paramétereinek az elemzése 5 meteorológiai állomás (Torda, Kolozsvár, Dézs, Beszterce és Marosvásárhely) és a Kolozsvári Aerológiai Állomás által szolgáltatott, 1961 és 1980 között feljegyzett adatok alapján történt. A szél irányának és sebességének az évi, évszaki és havi középértékeit a talajszinten és az 5 standard izobár szinten számítottuk ki. A felszín morfológiai sajátosságai és ennek a Kárpátok vonulatához viszonyított elhelyezkedése meghatározza a talajmenti szél paramétereinek regionális jellemzőit. A Kárpátok vonulatának a légmozgásra gyakorolt hatása körülbelül 3000 m magasságig érződik, fölötte a nyugati széljárás jellemző. Summary - The study presents some aspects of the ground level and altitudinal wind in the northern area of the Depression of Transsylvania. The analysis of the wind parameters is based on the data provided by 5 meteorological stations (Turda, Cluj-Napoca, Dej, Bistrija and Tárgu-Mure$) and the Cluj-Napoca Aerological Observatory, covering the interval between 1961-1980. The annual, seasonal and monthly average values of the direction and speed of the wind at ground level and at the five standard isobaric levels have been calculated. The regional differences of the wind parameters at ground level are affected by the morphologic peculiarities of the area and by its position in the vicinity of the Carpathian bow. In the altitude the influence of the Carpathians upon the circulation of the air is felt as high as 3000 m. Above this level the western circulation is predominant

Euler Characteristic of Polyhedral Graphs

Euler characteristic is a topological invariant, a number that describes the shape or structure of a topological space, irrespective of the way it is bent. Many operations on topological spaces may be expressed by means of Euler characteristic. Counting polyhedral graph figures is directly related to Euler characteristic. This paper illustrates the Euler characteristic involvement in figure counting of polyhedral graphs designed by operations on maps. This number is also calculated in truncated cubic network and hypercube. Spongy hypercubes are built up by embedding the hypercube in polyhedral graphs, of which figures are calculated combinatorially by a formula that accounts for their spongy character. Euler formula can be useful in chemistry and crystallography to check the consistency of an assumed structure. This work is licensed under a Creative Commons Attribution 4.0 International License

Persistent Borna Disease Virus (BDV) infection activates microglia prior to a detectable loss of granule cells in the hippocampus

Neonatal Borna Disease Virus (BDV) infection in rats leads to a neuronal loss in the cortex, hippocampus and cerebellum. Since BDV is a non-lytic infection in vitro, it has been suggested that activated microglia could contribute to neuronal damage. It is also conceivable that BDV-induced cell death triggers activation of microglia to remove cell debris. Although an overall temporal association between neuronal loss and microgliosis has been demonstrated in BDV-infected rats, it remains unclear if microgliosis precedes or results from neuronal damage. We investigated the timing of microglia activation and neuronal elimination in the dentate gyrus (DG) of the hippocampus. We found a significant increase in the number of ED1+ microglia cells as early as 10 days post infection (dpi) while a detectable loss of granule cells of the DG was not seen until 30 dpi. The data demonstrate for the first time that a non-lytic persistent virus infection of neurons activates microglia long before any measurable neuronal loss

Surgical options for treating achalasia: case series report

Scopul lucrării. Acalazia cardiei (AC) este o afecțiune de etiologie neuro-musculară rară, caracterizată de afectarea motilității esofagiene și acompaniată de disfuncția sfincterului esofagian inferior. Actualmente există metodele concurente de tratament chirurgical al AC, deși utilizarea acestora pe etape nu este standardizată. Scopul studiului este analiza seriei de cazuri clinice ale AC și raportarea rezultatelor tratamentului chirurgical acesteia. Materiale şi metode. În clinică au fost supuşi tratamentului chirurgical 7 pacienţi cu AC (aa. 2016-2022). La internare toți pacienții au prezentat acuze la disfagie moderată și dureri retrosternale postprandiale. Radioscopia cu suspensie baritată a conchis dilatarea excesivă a esofagului distal (≥4 cm la 5 pacienți, ≥6 cm la 2 pacienți), diminuarea motilității acestuia și îngustarea porțiunii distale „cioc de pasăre” la nivelul IGA. La examenul endoscopic s-a constatat dilatarea lumenului esofagian cu reținere salivei în lipsa obstacolelor rigide la nivelul joncțiunii gastro-esofagiene (JGE). Tehnica chirurgicală utilizată: esofagocardiomiotomia extramucoasă laparoscopică (EEL) Heller, acompaniată de procedeu antireflux (n=5) și dilatarea pneumatică cu balon în 2 cazuri (3 ședințe succesive cu balondilatator 3.0 și 4,0 cm, presiunea 15 psi, durata 30-45 sec). Rezultate. Durata medie a intervenţiei 70±50 min (interval 55-120 min). Mediana spitalizării 5 zile (interval 4- 7zile). Radioscopia cu substanță radioopacă a 5-a zi postoperator a confirmat și restabilirea tranzitului prin JGE. Un pacient cu semne de acalazie recurentă peste 3 ani după EEL a fost supus dilatării pneumatice cu ameliorarea semnelor de disfagie. Concluzii. EEL reprezintă o soluție efectivă în tratamentul AC. Dilatarea pneumatică ar putea fi o opțiune alternativă în tratamentul acestei maladii.Aim of study. Achalasia Cardia ( AC) is an esophageal motility disorder characterised by absence of peristalsis and insufficient lower esophageal sphincter relaxation. Currently there are competing methods of surgical therapy of AC, although their tailored use is not standardized. The aim of the study is to analyse clinical case series analysis of AC and to report the outcome of its surgical therapy Materials and methods. During the period from 2016 to 2022 we treated 7 patients with AC. All patients presented moderate dysphagia and food intake intolerance due to retrosternal pain. A barium esophagram demonstrated a dilated esophagus (≥4 cm in 5 cases, ≥6 cm in 2 cases), diminished peristalsis and a “rat tail” sign consistent with achalasia. An endoscopy revealed distal esophageal dilation and retained saliva in absence of any obstacles and rigidity of the tissues. The surgical treatment options included: laparoscopic Heller myotomy plus Dor fundoplication (n=5) and pneumatic dilation in 2 cases (3 successive procedures using 3.0 și 4,0 cm balloon dilators, 15 psi air held for 30-45 sec). Results. The mean operating time was 70±50 min (range 55-120 min). The average length of hospital stay was 5 days (range 4-7 days). Postoperative barium swallow demonstrated the improvement of contrast passage through gastroesophageal junction. We observed one case of AC recurrency 3 years after laparoscopic Heller procedure, the patient underwent the balloon dilation procedure with good relief of dysphagia.Conclusions. Laparoscopic Heller myotomy accompanied by postmyotomy anterior fundoplication is an effective option for treating AC. The pneumatic dilation procedure could be a viable alternative for some patients with achalasia

Astrocytes play a key role in activation of microglia by persistent Borna disease virus infection

Neonatal Borna disease virus (BDV) infection of the rat brain is associated with microglial activation and damage to certain neuronal populations. Since persistent BDV infection of neurons is nonlytic in vitro, activated microglia have been suggested to be responsible for neuronal cell death in vivo. However, the mechanisms of activation of microglia in neonatally BDV-infected rat brains remain unclear. Our previous studies have shown that activation of microglia by BDV in culture requires the presence of astrocytes as neither the virus nor BDV-infected neurons alone activate microglia. Here, we evaluated the mechanisms whereby astrocytes can contribute to activation of microglia in neuron-glia-microglia mixed cultures. We found that persistent infection of neuronal cells leads to activation of uninfected astrocytes as measured by elevated expression of RANTES. Activation of astrocytes then produces activation of microglia as evidenced by increased formation of round-shaped, MHCI-, MHCII- and IL-6-positive microglia cells. Our analysis of possible molecular mechanisms of activation of astrocytes and/or microglia in culture indicates that the mediators of activation may be soluble heat-resistant, low molecular weight factors. The findings indicate that astrocytes may mediate activation of microglia by BDV-infected neurons. The data are consistent with the hypothesis that microglia activation in the absence of neuronal damage may represent initial steps in the gradual neurodegeneration observed in brains of neonatally BDV-infected rats

Crystallographic Structure, Intermolecular Packing Energetics, Crystal Morphology and Surface Chemistry of Salmeterol Xinafoate (Form I).

Single crystals of salmeterol xinafoate (form I), prepared from slow cooled supersaturated propan-2-ol solutions, crystallise in a triclinic P‾1 symmetry with two closely related independent salt pairs within the asymmetric unit, with an approximately double unit cell volume compared to the previously published crystal structure(1). Synthonic analysis of the bulk intermolecular packing confirms the similarity in packing energetics between the two salt pairs. The strongest synthons, as expected, are dominated by coulombic interactions. Morphological prediction reveals a plate-like morphology, dominated by the {001}, {010} and {100} surfaces, consistent with experimentally grown crystals. Though surface chemistry of the slow growing {001} face comprises of large sterically hindering phenyl groups, weaker coulombic interactions still prevail from the alcohol group present on the phenyl and hydroxymethyl groups. The surface chemistry of the faster growing {010} and {100} faces are dominated by the significantly stronger cation/anion interactions occurring between the carboxylate and protonated secondary ammonium ion groups. The importance of understanding the cohesive/adhesive nature of the crystal surfaces of an API, with respect to their interaction with other API crystals and excipients and how that may impact formulation design is highlighted