Cutaneous leukocyte lineages in tolerant large animal and immunosuppressed clinical vascularized composite allograft recipients

Vascularized composite allografts (VCAs) can restore fully functional anatomic units in patients with limb amputations or severe facial tissue loss. However, acute rejection of the skin is frequently observed and underscores the importance of developing tolerance induction protocols. In this study, we have characterized the skin immune system in VCAs. We demonstrate infiltration of recipient leukocytes, regardless of rejection status, and in tolerant mixed hematopoietic chimeras, the co-existence of these cells with donor leukocytes in the absence of rejection. Here we characterize the dermal T cell and epidermal Langerhans cell components of the skin immune system in our porcine model of VCA tolerance, and the kinetics of cutaneous chimerism in both of these populations in VCAs transplanted to tolerant and nontolerant recipients, as well as in host skin. Furthermore, in biopsies from the first patient to receive a hand transplant in our program, we demonstrate the presence of recipient T cells in the skin of the transplanted limb in the absence of clinical or histological evidence of rejection.

Prolonged Survival Following Pig-to-Primate Liver Xenotransplantation Utilizing Exogenous Coagulation Factors and Costimulation Blockade

Since the first attempt of pig-to-primate liver xenotransplantation (LXT) in 1968, survival has been limited. We evaluated a model utilizing α-1,3-galactosyltransferase knockout donors, continuous posttransplant infusion of human prothrombin concentrate complex, and immunosuppression including anti-thymocyte globulin, FK-506, methylprednisone, and costimulation blockade (belatacept, n = 3 or anti-CD40 mAb, n = 1) to extend survival. Baboon 1 remained well until postoperative day (POD) 25, when euthanasia was required because of cholestasis and plantar ulcers. Baboon 2 was euthanized following a seizure on POD 5, despite normal liver function tests (LFTs) and no apparent pathology. Baboon 3 demonstrated initial stable liver function but was euthanized on POD 8 because of worsening LFTs. Pathology revealed C4d positivity, extensive hemorrhagic necrosis, and a focal cytomegalovirus inclusion. Baboon 4 was clinically well with stable LFTs until POD29, when euthanasia was again necessitated by plantar ulcerations and rising LFTs. Final pathology was C4d negative and without evidence of rejection, inflammation, or thrombotic microangiopathy. Thus, nearly 1-mo rejection-free survival has been achieved following LXT in two of four consecutive recipients, demonstrating that the porcine liver can support life in primates for several weeks and has encouraging potential for clinical application as a bridge to allotransplantation for patients with acute-on-chronic or fulminant hepatic failure.

The Effects of Exogenous Administration of Human Coagulation Factors Following Pig-to-Baboon Liver Xenotransplantation

We sought to determine the effects of exogenous administration of human coagulation factors following pig-to-baboon liver xenotransplantation (LXT) using GalT-KO swine donors. After LXT, baboons received no coagulation factors (historical control, n = 1), bolus administration of a human prothrombin concentrate complex (hPCC; 2.5 mL/kg, n = 2), continuous infusion of hPCC (1.0 mL/h, n = 1) or continuous infusion of human recombinant factor VIIa (1 µg/kg per hour, n = 3). The historical control recipient demonstrated persistent thrombocytopenia despite platelet administration after transplant, along with widespread thrombotic microangiopathy (TMA). In contrast, platelet levels were maintained in bolus hPCC recipients; however, these animals quickly developed large-vessel thrombosis and TMA, leading to graft failure with shortened survival. Recipients of continuous coagulation factor administration experienced either stabilization or an increase in their circulating platelets with escalating doses. Furthermore, transfusion requirements were decreased, and hepatic TMA was noticeably absent in recipients of continuous coagulation factor infusions compared with the historical control and bolus hPCC recipients. This effect was most profound with a continuous, escalating dose of factor VIIa. Further studies are warranted because this regimen may allow for prolonged survival following LXT.

Nano and micro reoriented domains and their relation with the crystal structure in the New Fe1.5Zn1.5B7O13Cl boracite

New iron-zinc chlorine single crystals of Fe1.5Zn1.5B7O13Cl boracite were grown by chemical transport reactions in closed quartz ampoules, at a temperature of 1173 K. The crystal structure was characterized by X-ray powder diffraction (XRD) using the Rietveld refinement method and belongs to the trigonal/rombohedral system with space group R3c (No. 161). The cell parameters were a = 8.5726(1) angstroms, c = 21.0116(4) angstroms, V = 1337.26(3) angstroms3 and Z = 6. The refinement successfully proceeded and ended with sound merit figure values chi2 = 2.25, R(B) = 6.12%. Chemical analysis was performed with X-ray energy dispersive spectroscopy (EDS) and X-ray fluorescence (XRF). Ferroelectric nano and micro reoriented domains were found in this material using polarizing optical microscopy (PLM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The examination by TEM showed that in the trigonal/rombohedral system of Fe1.5Zn1.5B7O13Cl nanodomain structures exist. Thin (50-100 nm) mostly planar domains parallel to (100) were frequently observed in Fe1.5Zn1.5B7O13Cl boracite.

The crystal structure of FeInGe2O7

A new iron indium germanate has been prepared as polycrystalline powder material which crystallizes in the monoclinic system (S.G. C2/m, No. 12). The structure was characterized by X-ray powder diffraction and Rietveld refinement of the resulting diffraction pattern. The cell parameters are a = 6.5124(4) Å, b = 8.5914(5) Å, c = 4.8936(3) Å, β = 102.683(2)°, V = 267.12(3) Å3 and Z = 2. The structure contains R+3 cations (R=Fe, In) almost equally distributed in distorted RO6 octahedral sites. These octahedra are joined by edge sharing forming a hexagonal arrangement on the ab planes. The RO6 octahedra layers are held together by sheets of isolated Ge2O7 diorthogroups constituted by a double tetrahedra sharing a common vertex. This compound has the thortveitite structure and keeps a strong relationship with the FeYGe2O7 germanate, which presents two R+3 sites with six-coordinated (R=Fe) and seven-coordinated (R=Y) oxygens, corresponding to the different symmetry given by the monoclinic space group P21/m (No. 11)

Effect of cigarette smoking on periodontal status of healthy young adults

BACKGROUND

It has been shown that tobacco is a significant risk factor for periodontal disease; however, there have been few studies on young populations where problems of general health can be discounted. The purpose of this study was to examine the influence of tobacco consumption on the periodontal condition of a young, healthy population.

METHODS

The study population consisted of 304 young Caucasian males (average age 19.38 +/- 0.72 years) entering the Armed Forces. All the subjects completed a self-administered questionnaire on age, oral hygiene habits, previous dental examinations, and quantity and length of tobacco use. The periodontal examination consisted of the plaque index (PI); periodontal bleeding index (PBI); probing depth (PD); and clinical attachment level (CAL). One- and 2-way ANOVA was used to compare data recorded between smokers and non-smokers.

RESULTS

Forty-six percent of subjects reported that they brushed their teeth at least once a day, but only 13% visited a dentist at least once a year. Over half (53%) were habitual smokers, 43% smoking between 5 and 20 cigarettes per day; 39% of the smokers had been smoking for less than 5 years. Mean PI was 31.24 +/- 14.88 (27.19 +/- 15.93 for smokers and 35.78 +/- 12.17 for non-smokers), with significant differences between non-smokers and those who smoked 5 to 20 cigarettes per day (26.85 +/- 16.11, P<0.0001). Mean PBI was 42.29 +/- 8.43 (non-smokers 44.67 +/- 6.53 and smokers 40.17 +/- 9.46). Significant differences were found between the PBI of the non-smokers and of those who smoked 5 to 20 cigarettes per day (39.90 +/- 9.64, P <0.0001). There were also differences in the PBI between those who brushed their teeth once (40.53 +/- 9.61) and twice (44.86 +/- 5.9) a day (P<0.0001). Mean PD was 1.62 +/- 0.43 mm (non-smokers 1.56 +/- 0.36 and smokers 1.68 +/- 0.49). Deeper probing depths were recorded among smokers than among non-smokers, with statistically significant differences (P<0.049); statistically significant differences were also found between those who attended (1.49 +/- 0.50) and those who did not attend (1.65 +/- 0.42) regular dental check-ups (P<0.031). Mean CAL 1.75 +/- 0.41 (non-smokers 1.64 +/- 0.32 and smokers 1.82 +/- 0.44).

CONCLUSIONS

It may be concluded that, even at such an early age, tobacco consumption affects the periodontal health. It is necessary to inform young smokers of the risk of tobacco use regarding periodontal health.