A comparative study on immunosuppressive effects of cyclosporin A and FK 506 on peripheral blood lymphocytes in dogs

Immunosuppressive effects of cyclosporin A (CsA) and FK 506 (FK) on peripheral blood lymphocytes were studied in dogs in respect to mixed lymphocyte reaction, proliferative responses to recombinant interleukin-2 (rIL-2), phytohemagglutinin (PHA) and concanavalin-A (Con-A); phenotypes of OKIa1, CD3, CD8 and surface IgM; cytotoxic activity against xenogeneic tumor cells. CsA (2.0 or 5.0 mg/kg, intravenously) or FK (0.16 mg/kg, intramuscularly) was given to mongrel dogs every morning for serial 21 days. The blood concentrations of CsA, measured as trough levels by fluorescence polarization method, ranged from 37 to 350 ng/ml in dogs administered at 2.0 mg/kg and from 170 to 894 ng/ml in dogs administered at 5.0 mg/kg during treatment, respectively. In dogs treated with FK at a dose of 0.16 mg/kg, the drug concentrations in the plasma during treatment ranged from 0.16 to 1.8 ng/ml. Mixed lymphocyte reaction and proliferative responses to rIL-2, PHA and Con-A, which were declined by CsA, were not affected by FK. In contrast, the proportion of OKIa1+ cells was not affected by CsA, whereas FK decreased the proportion of OKIa1+ cells progressively during the course of treatment. Cytotoxic activity was suppressed by both CsA and FK. These results possibly indicate that CsA and FK exert their immunosuppressive effects via different mechanisms.     

A bacteriological survey of an oyster-growing area: The Oualidia Lagoon,Morocco

A 3-year bacteriological survey of an oyster-growing area in Morocco, where the Japanese oyster (Crassostrea gigas) is grown, showed that the contamination of this lagunar ecosystem was not continuous but intermittent and that animal manure and human recreational activities were important sources of pollution. The major source of contamination was of animal origin, except during the summer, when human contamination prevailed.     

Analysis of the Drosophila female sterile mutation fs(1) 1304 by pole cell transplantation experiments

The Drosophila melanogaster mutant fs(1)1304 is an ovary autonomous female sterile mutant that causes abnormal morphology of the egg. Vitellogenesis proceeds at an abnormally slow rate in homozygous females. We have used pole cell transplantation to construct germ line mosaics in order to determine whether the 1304 defect depends upon the genotype of the germ line cells (oocyte or nurse cells) or the somatic line (follicle cells). We have found that the germ line is the primary target tissue where the mutant gene is expressed.     

Failure to Reject an Allografted Tumor after Elimination of Macrophages in Mice

After an i.p. transplantation of an allogeneic tumor (Meth A) to C57BL/6 mice, a macrophage (MΦ)-rich, non-T, non-NK cell population is induced as the major infiltrate and cytotoxic cells. We here evaluated the role of the MΦs in the rejection of allografted Meth A cells and characterized the MΦs in comparison with other well-known MΦs. At all time intervals after transplantation, the highest cytotoxic activities against Meth A tumor were obtained with the MΦ-rich population. In addition, the lymphocyte-rich population had a significant but low cytotoxic activity, whereas two other population types, granulocytes and large granular cells, were inactive. When the MΦ-rich or the T cell-depleted MΦ-rich population was i.p. transplanted simultaneously with Meth A cells into untreated C57BL/6 mice, the tumor cells were rejected without growth. After specific elimination of MΦs by in vivo application of dichloromethylene diphosphonate-containing liposomes, the cytotoxic activity against Meth A cells was hardly induced at the transplantation site of Meth A cells and the allografted Meth A tumor continued to grow, indicating that a type of MΦ is the effector cell essential for the rejection. In contrast to other well-known MΦs, the cytotoxic activity against Meth A cells was cell-to-cell contact dependent and soluble factor (e.g., NO and TNF-α) independent. Moreover, the cytotoxic activity of the MΦs (H-2^b) against ⁵¹Cr-labeled Meth A (H-2^d) cells was inhibited by the addition of unlabeled H-2^d, but not H-2^a, H-2^k or H-2^b, lymphoblasts as well as Meth A cells, implying the specific interaction of the MΦs with H-2^d cells.     

兔核移植胚胎起始发育的超微结构研究

对兔核移植胚胎起始发育的超微结构变化进行电镜观察,并与供体桑椹胚细胞,受体卵母细胞及同期正常受精胚胎的超微结构进行比较,“原核”期兔核移植胚胎的超微结构明显不同于供体桑椹胚细胞及受体卵母细胞的超微结构,而与同期正常受精胚胎相似,但有些核移植胚胎中皮质反应,及核仁和线粒体中出电子致密的网眼结构,与正常受精卵存在差别,分裂至２－细胞期时,与正常２－细胞胚超微结构更相似,结果提示,兔胚胎细胞核移植后,供     

Micropropagation ofDalbergia sissoo from nodal explants of mature trees

A method for micropropagation ofDalbergia sissoo has been developed. Single node segments obtained from coppice shoots of a mature tree (20 – 25 year old) produced 3–4 shoots per explant on Murashige and Skoog (MS) medium containing 4.4 x 10⁻⁶ M benzylaminopurine (BAP) and 4.4 × 10⁻⁷ M of Β-naphthoxy acetic acid (NOA) (shoot multiplication medium) within 4 weeks. Thein vitro regenerated shoots were 3 – 4 cm in length and provided 2 to 3 culturable nodal segments which on shoot multiplication medium again produced 3–4 shoots. Following this procedure 18–24 shoots were produced from single nodal segment within 60 d. 80 % of the shoots directly produced five roots when they were firstly treated with MS medium supplemented with 10⁻⁵ M indole-3-butyric acid (IBA) and subsequently transferred to half strength liquid MS medium containing 1 % activated charcoal followed by half strength liquid MS free hormones, vitamins and activated charcoal. Thein vitro raised plants were hardened for survival after transplantation to soil by exposing them to various humidity conditions, gradually from higher to low, with nearly 100 % transplant success. Acknowledgement: Authors are grateful to CSIR and DST, New Delhi for financial assistance.     

Mini-review: Islet transplantation to create a bioartificial pancreas

Donor scarcity precludes the use of pancreatic transplantation to treat type I diabetes. Xenogeneic islet transplantation offers the possibility of overcoming this problem; however, it entails the use of immunoisolation devices to prevent immune rejection of the transplanted islets. These devices consist of a semipermeable membrane, which surrounds the islets and isolates them from the host's immune system, while allowing the passage of insulin and essential nutrients, including glucose. Problems associated with proposed device designs include diffusion limitations, biocompatibility, device retrieval in the event of failure, and mechanical integrity. Microencapsulation appears to be the most promising system of immunoisolation, however, the design of a device suitable for human clinical use remains a challenge. (c) 1994 John Wiley & Sons, Inc.     

Human T Cell Leukemia Virus Type 1 (HTLV-1) Antibodies in Healthy Populations and Renal Transplanted Patients in the North-East of Brazil

The seroprevalence of human T cell leukemia virus type 1 (HTLV-1) infection was investigated in Brazilians (570): native inhabitants (298) and descendants from Japanese (272) living in Recife and its neighborhoods—North-east of Brazil. Furthermore, polytransfused renal transplanted patients (54) were also examined for the serological status to this virus. The seropositivity to HTLV-1, screened by enzyme-linked immunosorbent assay (ELISA), was low: 1.34% for the local population and 0.73% for the descendants from Japanese. However, the seropositivity for the renal transplanted patients was found to be 11.1%. This higher value suggests that this retrovirus infection seems to be of importance in this clinical condition.     

The Role of Cellular and Extracellular Matrix Adhesion Proteins in Organ Transplantation

The specific adhesion of cells to other cells or to particular tissue microenvirorvments is a basic function of cell migration and recognition, and underlines many biologic processes including embryogenesis, repair and immunity. Leukocytes express an array of surface receptors broadly known as “accessory adhesion molecules.” which mediate most cell -cell interactions, direct lymphocyte traffic between anatomical compartments, and facilitate cellular adhesion to the inflammation or alloantigenic sites (Springer 1990). In addition, adhesion molecules are involved in the process of antigen recognition, and may costimulate cell activation and transformation. These proteins are thought to affect the very early antigen independent events between host leukocytes and vascular endothelium. Because of these activities, the subject of adhesion molecules is gaining interest in the field of organ transplantation, in both conceptualization and development of novel therapeutic strategies (de Sousa et al. 1991, Kupiec-Weglinski et al. 1993a, Heemann et al. 1993).