Successful islet allotransplantation in diabetic rats immunosuppressed with FK506: A functional and immunological study

The effect of a novel immunosuppressive agent, FK506, on fresh islet allografts was evaluated in diabetic rats across major histocompatibility complex (MHC) barriers with respect to the transplantation (TR) site, islet source, treatment regimen, and antidonor antibody (Ab) titers of the recipients after TR. The functional periods of Wistar (Wi) islets transplanted under kidney capsule (KC) or intraportally (IPo) and of a mixture of Wi and Lewis (Le) islets under KC or IPo in nonimmunosuppressed ACI rat recipients were 6.9 ± 0.4 (n = 7), 6.4 ± 0.5 (n = 7), 5.6 ± 0.4 (n = 7), and 6.2 ± 0.4 (n = 5) days, respectively. FK506 treatment at 1 mg/kg/d intramuscularly (IM) for 2 weeks (protocol I) following islet TR under KC and IPo significantly prolonged the allograft function to more than 71.8 ± 11.3 (n = 10) and 161.7 ± 18.6 (n = 11) days, respectively. Additional treatment with FK506 at 1 mg/kg/wk (protocol II) further increased the islet survival under KC to more than 212.6 ± 22.3 (n = 8) days. With this FK506 treatment protocol, the Wi + Le mixed-islet allograft function was extended to more than 106.1 ± 10.5 (n = 7) and 167.9 ± 28.6 (n = 7) days under KC and IPo, respectively. Nephrectomy in 8 8 ACI rats with long-term-functioning Wi (n = 6) and Wi + Le (n = 2) islet allografts resulted in their return to hyperglycemia. Immunohistochemical staining showed abundant insulin-positive cells at the graft site, with small numbers of CD4- and CD8-positive cells present in the vicinity of the normal-appearing islets. Macrophages were not detected. The immunosuppressive effect of FK506 was further tested in ACI rats presensitized by a previous Wi islet TR. When the duration between the first and second TR under KC was 114.3 ± 20.5 days, protocol II treatment significantly prolonged the graft function to more than 152.9 ± 28.7 (n = 8) days. However, with a short duration of about 2 weeks between the two TRs, the same FK506 protocol achieved islet graft function of 14.0 ± 3.8 days (n = 7). Additional immunosuppression with cyclophosphamide did not further improve the survival time. Antidonor Abs detected in ACI recipients of Wi islet allografts were significantly lower in the FK506-treated animals compared with the nontreatment group. Wi and Le skin grafts performed in three ACI rats with long-term-functioning Wi islets IPo caused the rejection of the islet allografts. Skin grafts were also rejected in the first-set fashion. Six ACI recipients with long-term-functioning IPo Wi islet allografts were rendered hyperglycemic by streptozocin (STZ) injection. Long-term normoglycemia without further FK506 immunosuppression was achieved following retransplantation with fresh Wi islets IPo (n = 2), but not under KC (n = 2). The results of the present study indicate that FK506 was an effective immunosuppressant for islet allotransplantation in diabetic ACI rats across MHC barriers with islets from two donor strains, as well as in sensitized recipients whose antidonor activities had subsided. The efficacy of the immunosuppression was influenced by the FK506 treatment protocol and the site of the islet transplant. The results suggest that FK506 could be useful in clinical islet TR. © 1994

Razine kemokina KC i IL-8 u serumu pasa prirodno zaraženih vrstom Babesia canis canis.

Canine babesiosis, caused by Babesia canis canis, is one of the commonest canine diseases in Croatia. It is known that systemic inflammatory response syndrome (SIRS), which is a hallmark of babesiosis, is regulated by the host production of several pro-inflammatory and anti-inflammatory cytokines that have been implicated as playing a critical role in the pathogenesis of the disease. In the course of larger research, serum concentrations of CXC chemokines keratinocyte chemoattractant (KC) and interleukin-8 (IL-8) were determined. The aim of the present study was to determine serum chemokine concentrations and to compare values between healthy and dogs with babesiosis. An additional aim was to determine if KC and IL-8 serum concentrations are an important contributing factor in the development of complicated babesiosis, and whether they affect the outcome of the disease. The results suggest that a higher serum concentration of KC-like is connected with the severity of anemia, leukocytosis and development of a complicated form of babesiosis. The IL-8 concentration positively correlates with granulocyte-lymphocyte ratio. In addition concentration of both chemokines was higher in dogs with complicated babesiosis. Therefore, the concentration of the observed chemokines could be considered as an important factor in the pathogenesis of canine babesiosis.Babezioza pasa uzrokovana vrstom Babesia canis canis jedna je od najčešćih bolesti pasa u Hrvatskoj. Poznato je da je sustavni upalni odgovor (SIRS), koji se smatra osnovom patofiziološkog procesa tijekom babezioze, reguliran međudjelovanjem niza proupalnih i protuupalnih citokina. Cilj ovog istraživanja bio je odrediti koncentraciju CXC kemokina: kemoatraktanta za keratinocite (KC) i interleukina 8 (IL-8) u serumu pasa oboljelih od babezioze te usporediti koncentraciju s koncentracijom ovih citokina u serumu zdravih pasa. Također se željelo ustanoviti je li je aktivnost KC i IL-8 povezana s razvojem kompliciranog oblika babezioze i ishodom bolesti. Koncentracija kemokina u serumu određivana je Luminex xMap tehnologijom komercijalnim multiplex kompletom specifičnim za pse. Dobiveni rezultati pokazali su da je aktivnost KC povezana s razvojem anemije i leukocitoze, dok koncentracija IL-8 pozitivno korelira s omjerom granulocita i limfocita. Viša koncentracija obaju kemokina povezana je s razvojem kompliciranog oblika bolesti. Stoga se koncentracija KC i IL-8 u serumu može smatrati važnim čimbenikom u patogenezi babezioze pasa

Razine kemokina KC i IL-8 u serumu pasa prirodno zaraženih vrstom Babesia canis canis.

Canine babesiosis, caused by Babesia canis canis, is one of the commonest canine diseases in Croatia. It is known that systemic inflammatory response syndrome (SIRS), which is a hallmark of babesiosis, is regulated by the host production of several pro-inflammatory and anti-inflammatory cytokines that have been implicated as playing a critical role in the pathogenesis of the disease. In the course of larger research, serum concentrations of CXC chemokines keratinocyte chemoattractant (KC) and interleukin-8 (IL-8) were determined. The aim of the present study was to determine serum chemokine concentrations and to compare values between healthy and dogs with babesiosis. An additional aim was to determine if KC and IL-8 serum concentrations are an important contributing factor in the development of complicated babesiosis, and whether they affect the outcome of the disease. The results suggest that a higher serum concentration of KC-like is connected with the severity of anemia, leukocytosis and development of a complicated form of babesiosis. The IL-8 concentration positively correlates with granulocyte-lymphocyte ratio. In addition concentration of both chemokines was higher in dogs with complicated babesiosis. Therefore, the concentration of the observed chemokines could be considered as an important factor in the pathogenesis of canine babesiosis.Babezioza pasa uzrokovana vrstom Babesia canis canis jedna je od najčešćih bolesti pasa u Hrvatskoj. Poznato je da je sustavni upalni odgovor (SIRS), koji se smatra osnovom patofiziološkog procesa tijekom babezioze, reguliran međudjelovanjem niza proupalnih i protuupalnih citokina. Cilj ovog istraživanja bio je odrediti koncentraciju CXC kemokina: kemoatraktanta za keratinocite (KC) i interleukina 8 (IL-8) u serumu pasa oboljelih od babezioze te usporediti koncentraciju s koncentracijom ovih citokina u serumu zdravih pasa. Također se željelo ustanoviti je li je aktivnost KC i IL-8 povezana s razvojem kompliciranog oblika babezioze i ishodom bolesti. Koncentracija kemokina u serumu određivana je Luminex xMap tehnologijom komercijalnim multiplex kompletom specifičnim za pse. Dobiveni rezultati pokazali su da je aktivnost KC povezana s razvojem anemije i leukocitoze, dok koncentracija IL-8 pozitivno korelira s omjerom granulocita i limfocita. Viša koncentracija obaju kemokina povezana je s razvojem kompliciranog oblika bolesti. Stoga se koncentracija KC i IL-8 u serumu može smatrati važnim čimbenikom u patogenezi babezioze pasa

Field and current distributions and ac losses in a bifilar stack of superconducting strips

In this paper I first analytically calculate the magnetic-field and sheet-current distributions generated in an infinite stack of thin superconducting strips of thickness d, width 2a >> d, and arbitrary separation D when adjacent strips carry net current of magnitude I in opposite directions. Each strip is assumed to have uniform critical current density Jc, critical sheet-current density Kc = Jc d, and critical current Ic = 2a Kc, and the distribution of the current density within each strip is assumed to obey critical-state theory. I then derive expressions for the ac losses due to magnetic-flux penetration both from the strip edges and from the top and bottom of each strip, and I express the results in terms of integrals involving the perpendicular and parallel components of the magnetic field. After numerically evaluating the ac losses for typical dimensions, I present analytic expressions from which the losses can be estimated.Comment: 8 pages, 9 figure

Expression of HGF and c-met proteins in human keratoconus corneas

© 2015 Jingjing You et al. Keratoconus (KC) is a progressive degenerative inflammatory-related disease of the human cornea leading to decreased visual function. The pathogenesis of KC remains to be understood. Recent genetic studies indicate that gene variants of an inflammation-related molecule, hepatocyte growth factor (HGF), are associated with an increased susceptibility for developing KC. However HGF protein expression in KC has not been explored. In this initial study, we investigated late-stage KC and control corneas for the expression of HGF and its receptor mesenchymal-epithelial transition factor (c-Met/Met). KC buttons (8 mm diameter) (n = 10) and whole control corneas (n = 6) were fixed in 10% formalin or 2% paraformaldehyde, paraffin embedded and sectioned. Sections were immunolabelled with HGF and c-Met antibodies, visualised using immunofluorescence, and examined with scanning laser confocal microscopy. Semiquantitative grading was used to compare HGF and c-Met immunostaining in KC and control corneas. Overall, KC corneas showed increased HGF and c-Met immunostaining compared to controls. KC corneal epithelium displayed heterogeneous moderate-to-strong immunoreactivity for HGF and c-Met, particularly in the basal epithelium adjacent to the cone area. Taken together with the recent genetic studies, our results further support a possible role for HGF/c-Met in the pathogenesis of KC

Tear mediators in corneal ectatic disorders

A cornea ectaticus betegségeinek népegészségügyi jelentőségük van. Ezen kórképeket a cornea szerkezetének progresszív deformációja és elvékonyodása jellemzi. A pellucid marginális degeneráció (PMD) nagyon ritka, a perifériás cornea alsó részének elvékonyodásával járó kórkép, míg a leggyakoribb cornealis ectasia, a keratoconus (KC) esetében a szaruhártya jellegzetesen kúpszerű alakot vesz fel. Nem ismert pontosan, hogy teljesen különböző betegségekről van-e szó, vagy ugyanannak a kórképnek a fenotípusus variációiról. Klasszikusan a coneális ectasiákat nem gyulladásos eredetű betegségekként tartjuk számon, azonban a mostanában megjelent tanulmányok felvetik a gyulladásos faktorok kulcsszerepét. A KC-s betegek könnyében előforduló biomarkereket korábbi tanulmányok már tanulmányozták, azonban PMD-ben még nem történtek ilyen vizsgálatok. Számos mediátor (IL-6, IL-10, CXCL8/IL-8, CXCL10/IP-10, CCL5/RANTES, MMP-9, MMP-13, TIMP-1, NGF, tPA és PAI-1) koncentrációjának meghatározását tűztük ki célul PMD-s, valamint KC-s betegek könnymintáiból, hogy feltárjuk a két betegség között lévő biokémiai különbségeket. Az MMP-9 szignifikánsan eltért a két ectaticus betegcsoport között. Az MMP-9 és a TIMP-1 aránya 2,45 volt a PMD-s, 0,4 a KC-s és 0,23 a kontrollcsoportban. Néhány korábbi tanulmány a könnyben lévő biomarkerek és a KC súlyossága közötti kapcsolatot vizsgálja. Ezen publikációk limitációja a kevés vizsgált beteg, illetve mediátor, valamint a szubklinikai esetek hiánya. Kutatásunk során célul tűztük ki különböző mediátorok (IL-6, IL-10, CXCL8 /IL-8, CCL5/RANTES, MMP-9, MMP-13, TIMP-1, tPA és PAI-1) könnyben lévő koncentrációjának vizsgálatát, valamint a biomarkerek között lévő asszociációk feltérképezését a KC-ban szenvedő páciensek teljes spektrumában, illetve egészségesek esetében. Ráadásul, ezen mediátorok és a KC súlyosságát jellemző Scheimpflug paraméterek közötti korreláció megismerését is elterveztük. Továbbá célunk volt a Scheimpflug képalkotó paraméterek és az asthma bronchiale KC-ban való előfordulása közötti kapcsolat vizsgálata is. Vizsgálatunk feltárja a különböző könnyben lévő mediátorok kooperációját, melyek részt vesznek a KC komplex patomechanizmusában. Tanulmányunk megmutatja a könnyben lévő mediátorok és a Sheimpflug paraméterek közötti asszociációkat, megerősíti a gyulladás szerepét a KC patogenezisében. A mediátorok pontos szerepének meghatározása és a KC progressziójának vizsgálata a későbbiekben alapul szolgálhat a patológiás cornealis elvékonyodás helyi gátlásához, vagy a végleges terápiához.Corneal ectatic disorders have importance in public health. They are characterized by progressive deformation of the corneal architecture. PMD is a very rare peripheral thinning disorder of the inferior cornea, while KC is the most common primary corneal ectatic disease that gives rise to a cone-shaped cornea. It is not known whether PMD and KC are distinct diseases or whether they represent different clinical presentations of the same underlying disease process. Corneal ectatic disorders are generally believed to be non-inflammatory diseases, however, recent studies have suggested that ectatic disorders are inflammatory conditions. Biomarkers in the tear film have been studied in patients with KC but no studies have been reported for PMD. Our aim was to determine and to compare the concentrations of various mediators (IL-6, IL-10, CCL5/RANTES, CXCL8/IL-8, CXCL10/IP-10, MMP-9, MMP-13, TIMP-1, tPA, PAI-1 and NGF) in the tear film of patients with PMD and KC in order to reveal any possible biochemical differences between these two entities. MMP-9 presented relevant variances between the two patient groups. The ratios of MMP-9 and TIMP-1 were 2.45, 0.40 and 0.23 in PMD, KC and the controls, respectively. A few preliminary studies examining the association between biomarkers in the tear fluid and the severity of KC, but the limitations of these reports are the small number of patients, or the few examined mediators, or the lack of subclinical cases. We aimed to determine associations between biomarkers in tear fluid (IL-6, IL-10, CXCL8/IL-8, CCL5/RANTES, MMP-9, MMP-13, TIMP-1, tPA, and PAI-1) in the whole spectrum of keratoconic eyes and normal eyes. An additional goal was to explore associations between these mediators and the Scheimpflug parameters which characterize the severity of KC. Our aim was also to examine the relationship between the Scheimpflug imaging parameters and bronchial asthma in KC. This study reveals the cooperation of the different mediators in tears all taking part in the complex pathomechanism of KC. Our study reveals associations between tear biomarkers and Scheimpflug parameters, confirms that inflammation is involved in the pathogenesis of KC. Determination of the precise role of these mediators, as well as examination of the progression of KC serve then as a platform for local inhibition of pathological corneal thinning, or eventual treatment

Attempted reduction of a carbazolyl-diiodoalane

We report details of our attempts to reduce the bulky carbazolyl diiodoalane [R–AlI$_{2}$]. The reducing agents employed include KC$_{8}$, Cp$^{*}$$_{2}$Co and the Mg(I) compound [($^{Mes}$BDI)Mg]$_{2}$. The use of KC$_{8}$ allowed the spectroscopic observation of the alanediyl [R–Al]. With Cp$^{*}$$_{2}$Co as the reducing agent, the alanediyl [R–Al] was obtained as a crystalline material in low yield, but paramagnetic impurities remained. When diiodoalane [R–AlI$_{2}$] was treated with [($^{Mes}$BDI)Mg]$_{2}$, no reduction but a 2 : 1 addition was observed

Observations of pumping and vortex dynamics due to a cylinder oscillating normal to a plane wall

Understanding the fluid dynamics associated with a circular cylinder oscillating normal to a plane wall is important for safe design of offshore infrastructure, such as power cables and pipeline risers. This paper investigates the fluid dynamics of an oscillating cylinder with no imposed incident current experimentally using flow visualisation and force measurements where the ratio of the cylinder Reynolds number (Re) to Keulegan–Carpenter number (KC) is β = 500 and KC varies between 2 and 12. The minimum distance between the cylinder and wall was between 12.5 % and 50 % of the diameter. Across this parameter space three primary vortex flow regimes were observed: (i) for KC ≤ 5, the flow field is approximately symmetric about the cylinder centreline and the velocity field between the cylinder and the wall resembled a pumping flow in phase with cylinder motion, which is well predicted by potential theory for most of the cycle; (ii) for 5 < KC < 8, the flow field is increasingly asymmetric but with frequent switching of the side associated with vortex shedding; and (iii) for KC ≥ 8, the flow field is consistently asymmetric due to vortex shedding. The in-line force increases when the cylinder is near the wall due to dynamic pressures associated with pumping. This increase can be estimated using potential theory superimposed onto the force time history for an isolated cylinder at the same KC and Re. This study complements recent numerical modelling focused on low Reynolds number conditions and provides important insights into the fluid mechanics associated with trenching beneath cable and pipeline risers

Kempe Classes and Almost Bipartite Graphs

Let $G$ be a graph and $k$ be a positive integer, and let $Kc(G, k)$ denote the number of Kempe equivalence classes for the $k$-colorings of $G$. In 2006, Mohar noted that $Kc(G, k) = 1$ if $G$ is bipartite. As a generalization, we show that $Kc(G, k) = 1$ if $G$ is formed from a bipartite graph by adding any number of edges less than $\binom{\lceil k/2\rceil}2+\binom{\lfloor k/2\rfloor}2$. We show that our result is tight (up to lower order terms) by constructing, for each $k \geq 8$, a graph $G$ formed from a bipartite graph by adding $(k^2+8k-45+1)/4$ edges such that $Kc(G, k) \geq 2$. This refutes a recent conjecture of Higashitani--Matsumoto.Comment: 7 pages, 2 figures; 2nd version incorporates reviewer feedbac