The impact of cell surface PEGylation and short-course immunotherapy on islet graft survival in an allogeneic murine model

Transplantation of islets of Langerhans in patients with type 1 diabetes allows for improved metabolic control and insulin independence. The need for chronic immunosuppression limits this procedure to selected patients with brittle diabetes. Definition of therapeutic strategies allowing permanent engraftment without the need for chronic immunosuppression could overcome such limitations. We tested the effect of the use of protoporphyrins (CoPP and FePP), powerful inducers of the cytoprotective protein hemeoxygenase 1 (HO-1), on allogeneic islet graft survival. Chemically induced diabetic C57BL/6 mice received DBA/2 islets. Treatment consisted in peritransplant administration of CoPP or saline. Islets were either cultured in the presence of FePP or vehicle before implant. Short-course administration of CoPP led to long-term islet allograft survival in a sizable proportion of recipients. Long-term graft-bearing animals rejected third-party islets while accepting a second set donor-specific graft permanently, without additional treatment. Preconditioning of islets with FePP by itself led to improved graft survival in untreated recipients, and provided additional advantage in CoPP-treated recipients, resulting in an increased proportion of long-term surviving grafts. Preconditioning of the graft with protoporphyrins prior to implant resulted in reduction of class II expression. Administration of protoporphyrins to the recipients of allogeneic islets also resulted in transient powerful immunosuppression with reduced lymphocyte proliferative responses, increased proportion of regulatory cells (CD4+CD25+), decreased mononuclear cell infiltrating the graft, paralleled by a systemic upregulation of HO-1 expression. All these mechanisms may have contributed to the induction of donor-specific hyporesponsiveness in a proportion of the protoporphyrintreated animals.

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Mesenchymal Stem Cell Therapy with Co-Stimulation Blockers Prolonged Marginal Mass of Islet Graft Survival in Allogeneic Murine Model

Transplantation Journal ◽

10.1097/00007890-201211271-01436 ◽

2012 ◽

Vol 94 (10S) ◽

pp. 732

Author(s):

T. Takahashi ◽

M. Kumagai-Braesch ◽

J. Holgersson ◽

T. Lundgren ◽

A. Tibell

Keyword(s):

Stem Cell ◽

Mesenchymal Stem Cell ◽

Cell Therapy ◽

Graft Survival ◽

Stem Cell Therapy ◽

Murine Model ◽

Islet Graft ◽

Mesenchymal Stem Cell Therapy

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Mesenchymal Stem Cell Therapy with Co-Stimulation Blockers Prolonged Marginal Mass of Islet Graft Survival in Allogeneic Murine Model

Transplantation Journal ◽

10.1097/00007890-201211271-00383 ◽

2012 ◽

Vol 94 (10S) ◽

pp. 206

Author(s):

T. Takahashi ◽

M. Kumagai-Braesch ◽

J. Holgersson ◽

T. Lundgren ◽

A. Tibell

Keyword(s):

Stem Cell ◽

Mesenchymal Stem Cell ◽

Cell Therapy ◽

Graft Survival ◽

Stem Cell Therapy ◽

Murine Model ◽

Islet Graft ◽

Mesenchymal Stem Cell Therapy

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Absence of CXCL10 prolongs islet graft survival in an autoimmune mouse model for Type 1 Diabetes

Diabetologie und Stoffwechsel ◽

10.1055/s-0035-1556570 ◽

2015 ◽

Vol 10 (04) ◽

Author(s):

C Bender ◽

S Christen ◽

E Hintermann ◽

U Christen

Keyword(s):

Type 1 Diabetes ◽

Mouse Model ◽

Graft Survival ◽

Islet Graft ◽

Autoimmune Mouse

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Development of REDCAHOR—a Vegetable Research and Development Network in Central America

HortScience ◽

10.21273/hortsci.33.3.531b ◽

1998 ◽

Vol 33 (3) ◽

pp. 531b-531

Author(s):

J. Nienhuis

Keyword(s):

Integrated Pest Management ◽

Pest Management ◽

Central America ◽

Organic Production ◽

Vegetable Production ◽

Greenhouse Production ◽

Short Course ◽

Development Network ◽

Breeding And Genetics ◽

The Impact

REDCAHOR is the Spanish acronym for “Central American Vegetable Network.” Vegetables have traditionally been an important source of nutrients and vitamins in the diet in Central America. Vegetable production in this region is now changing as local consumers are demanding increased diversity and quality and international markets are expanding with “non-traditional” vegetable exports. The present restraints to expanded research and production of vegetables in the region include i) need for cultivars with increased insect and disease resistance, ii) poor and excessive use of pesticides, and iii) inadequate postharvest technology. In addition, there are few vegetable researchers in the region and response to their activities have not been coordinated. The goal of REDCAHOR is to develop a regional network of national institutions that can prioritize agendas and cooperate to maximize the impact of available resources. Establishment of a system of regional trials and cooperative regional programs in integrated pest management and plant breeding are currently under development. A series of regional workshops are planned, including integrated pest management, maintenance and use of genetic resources, organic production, and greenhouse production. In addition, REDCAHOR, in collaboration with the Escuela Agricola Panamerica in Honduras, will offer regional short-course training in vegetable breeding and genetics as well as vegetable production and management, including integrated pest management.

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Performance Analysis of Indentation Punch on High Energy Lithium Pouch Cells and Simulated Model Improvement

Polymers ◽

10.3390/polym13121971 ◽

2021 ◽

Vol 13 (12) ◽

pp. 1971

Author(s):

Lihua Ye ◽

Muhammad Muzamal Ashfaq ◽

Aiping Shi ◽

Syyed Adnan Raheel Shah ◽

Yefan Shi

Keyword(s):

Short Circuit ◽

Lithium Ion ◽

Mechanical Deformation ◽

High Energy ◽

State Of Charge ◽

Punch Test ◽

Short Course ◽

Model Cell ◽

The Impact

In this research, the aim relates to the material characterization of high-energy lithium-ion pouch cells. The development of appropriate model cell behavior is intended to simulate two scenarios: the first is mechanical deformation during a crash and the second is an internal short circuit in lithium-ion cells during the actual effect scenarios. The punch test has been used as a benchmark to analyze the effects of different state of charge conditions on high-energy lithium-ion battery cells. This article explores the impact of three separate factors on the outcomes of mechanical punch indentation experiments. The first parameter analyzed was the degree of prediction brought about by experiments on high-energy cells with two different states of charge (greater and lesser), with four different sizes of indentation punch, from the cell’s reaction during the indentation effects on electrolyte. Second, the results of the loading position, middle versus side, are measured at quasi-static speeds. The third parameter was the effect on an electrolyte with a different state of charge. The repeatability of the experiments on punch loading was the last test function analyzed. The test results of a greater than 10% state of charge and less than 10% state of charge were compared to further refine and validate this modeling method. The different loading scenarios analyzed in this study also showed great predictability in the load-displacement reaction and the onset short circuit. A theoretical model of the cell was modified for use in comprehensive mechanical deformation. The overall conclusion found that the loading initiating the cell’s electrical short circuit is not instantaneously instigated and it is subsequently used to process the development of a precise and practical computational model that will reduce the chances of the internal short course during the crash.

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