22 MALFORMATIONS FOUND BY AUTOPSY OF CLONED AND TRANSGENIC PIGLETS OF DIFFERENT BREEDS

2012 ◽  
Vol 24 (1) ◽  
pp. 123 ◽  
Author(s):  
M. Schmidt ◽  
K. D. Winter ◽  
J. Li ◽  
P. M. Kragh ◽  
Y. Du ◽  
...  
Keyword(s):  
Human Diseases ◽  
Weaned Piglets ◽  
Large White ◽  
Significance Level ◽  
Exact Test ◽  
Donor Cells ◽  
Transgenic Embryos ◽  
Considerable Loss ◽  
Overall Mortality

Viability of cloned and transgenic piglets is seriously compromised and one obvious reason could be malformations. The aim of the present study was therefore to describe gross pathological conditions in dead pre-weaned piglets born after transfer to Large White (LW) recipients of cloned (LW donor cells) or transgenic (Yucatan or Göttingen donor cells) embryos. Donor cells were fibroblasts and the Göttingen and Yucatan cells were made transgenic with 1 of 5 genes known to dispose for different human diseases. Handmade cloning was used to produce embryos that after 5 to 6 days of in vitro culture were transferred surgically to 108 LW sows 4 days after their natural heat. Of these, 21 sows delivered cloned LW piglets, whereas 17 and 16 sows, respectively, delivered transgenic Göttingen and Yucatan piglets. Stillborn and dead pre-weaned piglets were necropsied and malformations registered. Data were analysed by Fisher's exact test with a significance level of P < 0.05. In the 54 litters, total litter size ranged from 1 to 22 piglets (mean 5.4 ± 0.5) and the overall mortality rate until weaning on day 28 was 59%. Malformations were found in piglets from 38 litters where an average of 35% of the piglets showed malformations (between 8 and 100%). In those litters, 1 to 7 piglets had 1, 2, or several malformations (Table 1). The malformation rate in the autopsied transgenic Göttingen was 58% and in Yucatan 46%; these were significantly higher than in the autopsied cloned LW piglets with 18%. Some of the malformations seemed to be related to breed and/or transgene; for instance, heart malformations were most frequent in Yucatan litters (70%) independent of the transgene, whereas gallbladder and gonad malformations were more frequent in various litters with the same transgene. These results show that the use of cloning in pigs results in a considerable loss of piglets due to malformations and transgenic transformation of the cells used for cloning superimpose on this problem. In combination, these elements could seriously compromise the use of pigs as a model for human diseases and the choice of breeds and also transgenes for this kind of work should be considered carefully. However, further improvements in production of cloned/transgenic embryos may ultimately reduce the incidence of malformations. Table 1.Number of malformations in 54 litters of cloned or transgenic piglets

30 POSTMORTEM FINDINGS IN CLONED AND TRANSGENIC PIGLETS DEAD BEFORE WEANING

2015 ◽  
Vol 27 (1) ◽  
pp. 107 ◽  
Author(s):  
M. Schmidt ◽  
K. D. Winther ◽  
H. Callesen
Keyword(s):  
Human Diseases ◽  
Large White ◽  
Significance Level ◽  
Exact Test ◽  
Donor Cells ◽  
Cloning Technique ◽  
Limb Malformations ◽  
Transgenic Cells ◽  
Transgenic Technologies

Around 50% of cloned and transgenic piglets are lost during the first month after birth (Reprod. Fertil. Develop. 26, 124), and one reason is malformations of vital organs. The aim of the present study was to describe the distribution of malformations in piglets (until weaning, i.e. age <Day 28) born after transfer to Large White (LW) recipients of cloned embryos. Donor cells were fibroblasts either from LW (non-transgenic) or from Yucatan or Göttingen (made transgenic with 1 of 7 genes related to different human diseases). Handmade cloning was used to produce embryos that, after 5–6 days in vitro culture, were transferred to 202 LW sows 4 days after natural heat. Abortion occurred in 29 sows, and 6.5 ± 0.4 piglets per litter (from 1 to 22) were delivered from 116 sows (46 litters with LW piglets, 40 with Göttingen, 30 with Yucatan). In 78 of these litters (67%), autopsies were performed on 55 ± 4% of piglets stillborn or dead before weaning. Data were analysed by Fisher's Exact test with P < 0.05 as significance level. Malformations were found in 1 to 12 piglets per litter, with a higher malformation rate in transgenic Göttingen and Yucatan piglets (35% and 46% of all born, respectively) than in non-transgenic LW (17%). Many piglets showed 2 (24%) or more (6%) malformations. Some malformations seemed to be related to breed and/or transgene (see Table 1 for most frequent malformations); for example, heart malformations were most frequent in Yucatan litters independent of the transgene, whereas gall bladder and limb malformations were more frequent in Göttingen and in various litters with the same transgene. These results show that pig cloning results in a considerable loss of piglets, and that a majority of these can be related to various malformations. Use of transgenic cells for cloning only adds to this problem. Some malformations are related to the specific breed in use, but the general finding is that the problem is related to the cloning technique as such. However, because approximately half of the cloned piglets still survive, perhaps with unknown minor malformations, use of pigs as a model for human diseases is still realistic. But choice of breed and possible improvements of the transgenic technologies for this kind of work should be considered carefully. Table 1.Malformations in transgenic and nontransgenic cloned piglets dead before weaning

scholarly journals 78 ESTABLISHMENT OF PREGNANCIES IN LARGE WHITE SOW RECIPIENTS AFTER TRANSFER OF CLONED EMBRYOS OF DIFFERENT PIG BREEDS

2010 ◽  
Vol 22 (1) ◽  
pp. 197 ◽  
Author(s):  
M. Schmidt ◽  
P. M. Kragh ◽  
J. Li ◽  
L. Lin ◽  
Y. Liu ◽  
...  
Keyword(s):  
Technical Assistance ◽  
Abortion Rate ◽  
Fetal Mortality ◽  
Large White ◽  
Abdominal Incision ◽  
Significance Level ◽  
Exact Test ◽  
Donor Cells ◽  
Significant Difference

Production of cloned piglets, using normal or transgenic donor cells, has been of limited efficiency. One reason could be breed differences between recipient and embryos. The aim of this study was to compare pregnancies after transfer to Large White (LW) sow recipients of cloned LW embryos or cloned, transgenic minipig embryos. Large White donor cells were from LYxD, and minipig cells were transgenic with 1 of 5 genes related to different human diseases and from either Göttingen or Yucatan. The cells were used on Day 0 for handmade cloning (Du et al. 2005 Cloning Stem Cells 7, 199-205). The reconstructed embryos were cultured in vitro until transfer on Day 5 to 6. As recipients, 70 LW sows were weaned and anesthetized 4 days after natural heat. Through an abdominal incision the ovaries were controlled (CL formation, absence of cysts) and the embryos slowly introduced into the uterus via a catheter inserted 5 to 6 cm into the tip of the upper horn. To each of 33 recipients, 40 to 60 LW embryos were transferred, and 37 recipients each received 50 to 100 transgenic minipig embryos. Pregnancies were examined by ultrasound scanning every second week. Abortions were defined as absence of earlier confirmed scanning or delivery of aborted fetuses. Caesarean sections were performed on Day 114 (minipig) or Day 116 (LW) 24 h after injection of a prostaglandin analogue. At delivery, placental gross morphology was recorded with samples taken for later histology. The piglets were fed every 3 h with colostrum for the first 24 h and then by the recipient LW sow. Data were analyzed by Fisher’s Exact test with a significance level of P < 0.05. The overall pregnancy rate was 49% (34/70) with an abortion rate of 29% (8 aborted + 2 resorbed/34) from Day 30 to 45 giving 24/70 deliveries (34% of the transfers). There was no significant difference between minipig (54%, 20/37) and LW pregnancy results (42%, 14/33), although there tended to be more abortions with minipig pregnancies (8/20 v. 2/14; P = 0.14) resulting in 12 minipig and 12 LW litters of which 4 and 9, respectively, have grown up to adulthood. In almost every recipient the placenta and fetal membranes showed abnormal thick and edematous morphology. The total litter sizes ranged from 1 to 10 piglets (mean 4.4 ± 0.6), and in 13 of 24 litters there were 1 to 5 stillborn piglets. Except for one litter of 9 transgenic Yucatan piglets that all died within their first 2 weeks, the postnatal mortality of both LW- and mini-piglets seemed similar to that of farm piglets of the same age, and the piglets appeared normal with respect to weight gain, gross morphology, and behavior. These results demonstrate that, in spite of a rather high abortion rate and some fetal mortality, an acceptable birth rate can be achieved after transfer to LW recipients of cloned LW embryos (36%) as well as cloned, transgenic minipig embryos (32%). Therefore, a breed difference between the embryos and their recipient seems not to influence the pregnancy results. The authors thank B. Synnestvedt, H. Kristiansen, S. Starsig, A. Pedersen, J. Adamsen, R. Kristiansen, and K. Villemoes for invaluable technical assistance.

19 LIFETIME MORTALITY OF CLONED PIGLETS

2014 ◽  
Vol 26 (1) ◽  
pp. 124
Author(s):  
M. Schmidt ◽  
K. D. Winther ◽  
H. Callesen
Keyword(s):  
Perinatal Mortality ◽  
Donor Cell ◽  
Well Being ◽  
Perinatal Period ◽  
Large White ◽  
Significance Level ◽  
Exact Test ◽  
Donor Cells ◽  
Birth Data ◽  
Piglet Mortality

Perinatal mortality of cloned animals is a well-recognised problem, but it is not clear if and how the problems continue throughout the life of cloned animals. Here we report occurrence and causes of lifetime mortality of cloned piglets from their perinatal period and onwards. From 2006 until 2013, 178 Large White (LW) sows received Day 5–6 handmade cloned morulae or blastocysts where donor cells were from LW, Yucatan, or Göttingen, and were either transgenic or not. Pregnancy rate on Day 30 was 73%, but 19% terminated before term, resulting in 104/178 deliveries. For each litter, each piglet was characterised as either alive or stillborn (i.e. dead without signs of autolysis or dying during the first minutes after birth). Data were analysed by Fisher's Exact test with a significance level of P < 0.05. In the 104 litters, stillborn piglets were found in 54 (from 1 to 7 stillborn piglets in a litter), and the highest number of stillborns was found in Göttingen piglets (P < 0.05; see Table 1). Alive piglets were followed and their mortality registered, and they either died spontaneously (arthritis, pericarditis, enteritis, septicemia, lethal malformations) or were killed if they had other malformations, no weight gain, anorexia, bristly hair coat or signs of compromised well-being. Piglet mortality was highest in the perinatal period but remained high until weaning at Day 28 (see Table 1), so almost half of the alive piglets died during the first month; this preweaning mortality was highest in Yucatan piglets (P < 0.05), which also had the highest cumulative mortality. Further analyses are needed to describe differences observed between donor cell breeds. After weaning, where the pigs were kept under standard conditions, the mortality was at the normal level for the farm. Few died of infections with no breed differences, so most were killed over the subsequent months and years for various experimental purposes. The oldest pig lived until 6 years of age. During their life, no differences compared with noncloned pigs were observed in behaviour, growth, occurrence of diseases, or viability. This study confirms the well-known high perinatal mortality of cloned piglets and shows also high mortality until weaning. However, after weaning, mortality was not different from that of noncloned piglets. Table 1.Lifetime mortality rates in cloned piglets of different breeds and at different time periods after birth

23 IMPROVING EFFICIENCY IN WORK WITH TRANSFER OF CLONED PIG EMBRYOS

2014 ◽  
Vol 26 (1) ◽  
pp. 126 ◽  
Author(s):  
H. Callesen ◽  
Y. Liu ◽  
R. Li ◽  
M. Schmidt
Keyword(s):  
Large White ◽  
Mean Values ◽  
Xenopus Egg Extract ◽  
Egg Extract ◽  
Donor Cells ◽  
Chi Squared ◽  
Xenopus Egg ◽  
Working Day ◽  
One Way Anova

Cloning is a quite inefficient procedure with only around 10% of offspring born based on number of cloned embryos transferred. Every step to increase this level is therefore welcomed. Our group has worked with cloning of pig embryos since 2006, with the main purpose to establish a well-functioning cloning system to have transgenic piglets born as animal models for important human diseases. Here we report results from our attempts to improve efficiencies in several steps in the whole cloning procedure. Over 7.5 years, donor cells from 3 breeds were nontransgenic (50%, 4 types) or transgenic with 1 of 6 different types of gene. Oocytes from Large White (LW) sows or gilts were handmade cloned, so the zona-free cloned embryos were in vitro cultured until Day 5 to 6 to select 13 311 embryos (morulae or blastocysts) for transfer to 171 LW recipient sows or gilts. Of these, 126 were pregnant (74%; Day 35), but 20 aborted before term. A total of 704 offspring were delivered; half of the piglets were alive after 4 weeks and developed normally after that. Frequencies were compared using Chi-squared test; mean values by one-way ANOVA (SAS version 9.2; SAS Institute Inc., Cary, NC, USA). Specific improvements were tested in 4 areas: (1) donor cells: stimulating reprogramming using Xenopus egg extract (Liu et al. 2013 Reprod. Fertil. Dev. http://dx.doi.org/10.1071/RD13147); (2) oocytes: preferably from sows, but also using larger gilt oocytes (Li et al. 2013 Zygote http://dx.doi.org/10.1017/S0967199412000676); (3) transfer: using both uterine sides (Theriogenology 74 : 1233); (4) number of embryos transferred: after cloning with same nontransgenic cells, embryo numbers per recipient were reduced from 90 to 30 (see Table 1). As a consequence of these different activities, overall results improved over the 7.5-year period [first 3.5 years v. last 4 years: 48% (32/67) v. 90% (94/104) recipients pregnant after transfer (P < 0.05); 5.6 ± 0.6 (n = 22) v. 6.9 ± 0.5 (n = 84) piglets/litter]. In our system, one good cloning person can now produce all embryos needed for one recipient in one good working day. Transfer of fewer cloned embryos results in fewer piglets, but it reduces the workload to produce cloned embryos and does not reduce efficiency. Further work is still needed to better understand the biological and technical challenges in work with cloning; 2 important areas are quality evaluation of the donor cells used for cloning and the recipient's reaction to transfer of many embryos. In conclusion, a reasonable increase in the overall efficiency in pig cloning work was achieved, which reduces the need for personnel, time, and material when working with this technology. Table 1.Results of improving efficiency of cloning

23 Production of Genetically Modified Founder Pigs as Models for Human Diseases

2018 ◽  
Vol 30 (1) ◽  
pp. 151
Author(s):  
H. Callesen ◽  
Y. Liu ◽  
H. S. Pedersen ◽  
C. B. Sørensen ◽  
J. F. Bentzon
Keyword(s):  
First Generation ◽  
Genetically Modified ◽  
Donor Cell ◽  
Postnatal Period ◽  
Human Diseases ◽  
Large White ◽  
Donor Skin ◽  
Low Efficiency ◽  
Critical Phases

Pigs are increasingly used as genetically modified (GM) animal models for human diseases. Reliable methods to produce GM piglets are needed to produce at least one founder animal that can pass on the transgene to the next generation using conventional reproductive procedures. Somatic cell nuclear transfer (SCNT, “cloning”) is one such method, although it has a low efficiency with up to only 10% of offspring born based on number of cloned embryos transferred (Liu et al. 2014 Reprod. Fertil. Dev. 27, 429-439) and with a high percentage dying in the first days after birth (Schmidt et al. 2015 Theriogenology 84, 1014-1023). Furthermore, there is concern about the normality and viability of offspring in the following generations after cloning. Here, we report our results related to the latter question and describe the reliability of SCNT to produce healthy GM founder pigs for further studies. From 2006 to 2016, we worked with handmade cloning using donor skin cells from 4 breeds (2 minipigs, 2 standard pigs) that were non-GM or GM with 1 out of more than 20 genes. Cells were reconstructed with oocytes from Large White (LW) sows or gilts, and embryos were in vitro cultured for 5 to 6 days before selection for transfer to LW recipient sows or gilts (Callesen et al. 2014 Cell. Reprogram. 16, 407-410). Enough cloned embryos were produced with each type of GM donor cell for transfer to at least 2 recipients. During the first 4 years, the procedure was being established and refined, whereas in the last 7 years, it was used routinely (Table 1). In the latter period, the GM piglets alive after 30 days represented 17 of the 18 transgenes used. The GM piglets alive 30 days after birth were kept and developed as normal pigs. For 4 of the transgenes used, cloned minipigs were bred using standard breeding; in total, 106 piglets from 15 litters were born in the first generation after the cloning, and 138 piglets from 20 litters in the second generation. Both litter sizes and abnormality frequencies were within the expected range of the given breed (Yucatan or Göttingen), also noting that the pigs harbored a transgene and that some inbreeding was unavoidable due to the few founder piglets available. This work demonstrates that use of SCNT is a reliable way to produce GM founder piglets even though cloning does result in great losses during farrowing and the early postnatal period. However, having overcome these critical phases, the piglets seem to show no visible signs of their challenging background. The overall expense is, of course, high for production of each of the GM founder pigs, and this should be taken into consideration when deciding the species to use for creating a given GM animal model for modelling human diseases. Table 1.Results from 2010 to 2016 of using cloning to produce genetically modified (GM) and non-GM piglets

scholarly journals Invasive infections with Purpureocillium lilacinum: clinical characteristics and outcome of 101 cases from FungiScope® and the literature

2021 ◽  
Author(s):  
Rosanne Sprute ◽  
Jon Salmanton-García ◽  
Ertan Sal ◽  
Xhorxha Malaj ◽  
Zdeněk Ráčil ◽  
...  
Keyword(s):  
Amphotericin B ◽  
Organ Transplant ◽  
Solid Organ ◽  
Intrinsic Resistance ◽  
Breakthrough Infection ◽  
Purpureocillium Lilacinum ◽  
Invasive Infections ◽  
Oncological Diseases ◽  
Overall Mortality

Abstract Objectives To provide a basis for clinical management decisions in Purpureocillium lilacinum infection. Methods Unpublished cases of invasive P. lilacinum infection from the FungiScope® registry and all cases reported in the literature were analysed. Results We identified 101 cases with invasive P. lilacinum infection. Main predisposing factors were haematological and oncological diseases in 31 cases (30.7%), steroid treatment in 27 cases (26.7%), solid organ transplant in 26 cases (25.7%), and diabetes mellitus in 19 cases (18.8%). The most prevalent infection sites were skin (n = 37/101, 36.6%) and lungs (n = 26/101, 25.7%). Dissemination occurred in 22 cases (21.8%). Pain and fever were the most frequent symptoms (n = 40/101, 39.6% and n = 34/101, 33.7%, respectively). Diagnosis was established by culture in 98 cases (97.0%). P. lilacinum caused breakthrough infection in 10 patients (9.9%). Clinical isolates were frequently resistant to amphotericin B, whereas posaconazole and voriconazole showed good in vitro activity. Susceptibility to echinocandins varied considerably. Systemic antifungal treatment was administered in 90 patients (89.1%). Frequently employed antifungals were voriconazole in 51 (56.7%) and itraconazole in 26 patients (28.9%). Amphotericin B treatment was significantly associated with high mortality rates (n = 13/33, 39.4%, P = &lt;0.001). Overall mortality was 21.8% (n = 22/101) and death was attributed to P. lilacinum infection in 45.5% (n = 10/22). Conclusions P. lilacinum mainly presents as soft-tissue, pulmonary or disseminated infection in immunocompromised patients. Owing to intrinsic resistance, accurate species identification and susceptibility testing are vital. Outcome is better in patients treated with triazoles compared with amphotericin B formulations.

scholarly journals Artificial Caries Lesion Characteristics after Secondary Demineralization with Theobromine-Containing Protocol

Molecules ◽  
2021 ◽  
Vol 26 (2) ◽  
pp. 300
Author(s):  
Hani M. Nassar ◽  
Frank Lippert
Keyword(s):  
Mineral Content ◽  
Significance Level ◽  
Lesion Depth ◽  
Caries Lesion ◽  
Mineral Profile ◽  
Bonferroni Test ◽  
Bovine Enamel ◽  
Caries Lesions ◽  
Nail Varnish

Developing artificial caries lesions with varying characteristics is needed to adequately study caries process in vitro. The objective of this study was to investigate artificial caries lesion characteristics after secondary demineralization protocol containing theobromine and fluoride. Sixty bovine enamel slabs (4 × 3 mm) were demineralized using a Carbopol-containing protocol for 6 days. A baseline area (2 × 3 mm) was protected with acid-resistant nail varnish, after which specimens were exposed for 24 h to a secondary demineralization protocol containing acetic acid plus one of four fluoride/theobromine combinations (n = 15): theobromine (50 or 200 ppm) and fluoride (0 or 1 ppm). Specimens were sectioned and analyzed using transverse microradiography for changes in mineral content, lesion depth, and surface layer mineralization. Data was analyzed using paired t-test and analysis of variance followed by Bonferroni test at 0.05 significance level. After secondary demineralization, fluoride-containing groups had significantly deeper lesions (p = 0.002 and 0.014) compared to the group with 0 ppm fluoride and 50 ppm theobromine. Mineral content and lesion depth were significantly different compared to baseline for all groups. Theobromine did not show an added effect on mineral uptake. Theobromine-containing groups exhibited particularly deep lesions with a more uniform mineral profile in the presence of fluoride.

scholarly journals Antioxidant Fusion Protein SOD1-Tat Increases the Engraftment Efficiency of Total Bone Marrow Cells in Irradiated Mice

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3395
Author(s):  
Ting Bei ◽  
Xusong Cao ◽  
Yun Liu ◽  
Jinmei Li ◽  
Haihua Luo ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Fusion Protein ◽  
Bone Marrow Cells ◽  
Standard Procedure ◽  
Severe Infection ◽  
Copper Zinc Superoxide Dismutase ◽  
Donor Cells ◽  
Total Bone Marrow ◽  
Marrow Cells

Total body irradiation is a standard procedure of bone marrow transplantation (BMT) which causes a rapid increase in reactive oxygen species (ROS) in the bone marrow microenvironment during BMT. The increase in ROS reduces the engraftment ability of donor cells, thereby affecting the bone marrow recovery of recipients after BMT. In the early weeks following transplantation, recipients are at high risk of severe infection due to weakened hematopoiesis. Thus, it is imperative to improve engraftment capacity and accelerate bone marrow recovery in BMT recipients. In this study, we constructed recombinant copper/zinc superoxide dismutase 1 (SOD1) fused with the cell-penetrating peptide (CPP), the trans-activator of transcription (Tat), and showed that this fusion protein has penetrating ability and antioxidant activity in both RAW264.7 cells and bone marrow cells in vitro. Furthermore, irradiated mice transplanted with SOD1-Tat-treated total bone marrow donor cells showed an increase in total bone marrow engraftment capacity two weeks after transplantation. This study explored an innovative method for enhancing engraftment efficiency and highlights the potential of CPP-SOD1 in ROS manipulation during BMT.

scholarly journals Effects of chitosan on nitric oxide production and inducible nitric oxide synthase activity and mRNA expression in weaned piglets

2018 ◽  
Vol 60 (No. 8) ◽  
pp. 359-366
Author(s):  
J. Li ◽  
B. Shi ◽  
S. Yan ◽  
L. Jin ◽  
Y. Guo ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Mrna Expression ◽  
Inducible Nitric Oxide Synthase ◽  
No Production ◽  
Weaned Piglets ◽  
Inos Activity ◽  
Oxide Synthase ◽  
Inducible Nitric Oxide

The effects of chitosan on nitric oxide (NO) production and inducible nitric oxide synthase (iNOS) activity and gene expression in vivo or vitro were investigated in weaned piglets. In vivo, 180 weaned piglets were assigned to five dietary treatments with six replicates. The piglets were fed on a basal diet supplemented with 0 (control), 100, 500, 1000, and 2000 mg chitosan/kg feed, respectively. In vitro, the peripheral blood mononuclear cells (PBMCs) from a weaned piglet were cultured respectively with 0 (control), 40, 80, 160, and 320 &micro;g chitosan/ml medium. Results showed that serum NO concentrations on days 14 and 28 and iNOS activity on day 28 were quadratically improved with increasing chitosan dose (P &lt; 0.05). The iNOS mRNA expressions were linearly or quadratically enhanced in the duodenum on day 28, and were improved quadratically in the jejunum on days 14 and 28 and in the ileum on day 28 (P &lt; 0.01). In vitro, the NO concentrations, iNOS activity, and mRNA expression in unstimulated PBMCs were quadratically enhanced by chitosan, but the improvement of NO concentrations and iNOS activity by chitosan were markedly inhibited by N-(3-[aminomethyl] benzyl) acetamidine (1400w) (P&nbsp;&lt; 0.05). Moreover, the increase of NO concentrations, iNOS activity, and mRNA expression in PBMCs induced by lipopolysaccharide (LPS) were suppressed significantly by chitosan (P &lt; 0.05). The results indicated that the NO concentrations, iNOS activity, and mRNA expression in piglets were increased by feeding chitosan in a dose-dependent manner. In addition, chitosan improved the NO production in unstimulated PBMCs but inhibited its production in LPS-induced cells, which exerted bidirectional regulatory effects on the NO production via modulated iNOS activity and mRNA expression.

scholarly journals Induction of classical transplantation tolerance in the adult.

1989 ◽  
Vol 169 (3) ◽  
pp. 779-794 ◽  
Author(s):  
S X Qin ◽  
S Cobbold ◽  
R Benjamin ◽  
H Waldmann
Keyword(s):  
Bone Marrow ◽  
Transplantation Tolerance ◽  
Donor Strain ◽  
Skin Grafts ◽  
Donor Cells ◽  
Transplantation Antigens ◽  
Adult Bone ◽  
Tolerant State ◽  
Clonal Anergy

Transplantation tolerance across histoincompatibilities in multiple non-H-2 minors (B10.BR into CBA/Ca) and "minor" plus H-2D (B10.A into CBA/Ca) antigens has been achieved successfully by combined adult bone marrow transplantation and treatment with CD4 and CD8 mAbs. The tolerant state was confirmed by permanent acceptance of donor strain skin grafts, and in vitro unresponsiveness to donor cells. Tolerance was associated with partial donor chimerism to various degrees. Tolerance to minor transplantation antigens induced in this manner was restricted to recipient-type MHC. The possibility was raised that tolerance resulted, at least in part, from clonal anergy rather than deletion.

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