Tacrolimus (FK506) and sirolimus (rapamycin) in combination are not antagonistic but produce extended graft survival in cardiac transplantation in the rat

Combined use of tacrolimus (FK506) with sirolimus (rapamycin [RAPA]) was examined in a model of vascularized heart allograft in the rat. For prevention of acute rejection, three different combinations of low doses of FK506 and RAPA from day 1 up to day 14 after transplantation produced significantly longer cardiac allograft survival than each agent alone (P<0.05). Identical results were observed in a model of reversal of ongoing acute rejection, where two combinations of low doses of FK506 and RAPA from day 4 up to day 18 after surgery also demonstrated significantly longer graft survival than each immunosuppressant alone (P<0.05). All the low-dose-treated groups in these two models presented significantly longer heart graft survival than naive controls (P<0.05), confirming that both agents are potent immunosuppressants in the models chosen. These results also indicate that, in contrast with in vitro studies, the combined use of FK506 and RAPA in vivo did not produce antagonism, but rather had synergistic effect in prolonging the allograft survival as compared with each agent alone. It appears likely that the abundance of FKBP-12 available for binding in vivo prevents inhibitive competition of the two agents for their receptor.

[Study on expression of adherent proteins related to regulation of hematopoiesis in long-term cultured human bone marrow stromal cells]

OBJECTIVE

To study the molecular basis of bone marrow stromal cell supporting hematopoiesis.

METHODS

Immunoelectron microscopic localization of adherent protein related to regulation of hematopoiesis was performed by immunocolloidal gold labelling technique in the adherent layer of long-term cultured human bone marrow stromal cells (LTCHBMSC).

RESULTS

Adherent proteins were found to be expressed on LTCHBMSC. Double labelling revealed co-expression of these proteins and some specific markers for endothelial cells (vWF) and fibroblasts (Fb-sp). It was suggested that endothelial cells and fibroblasts in LTCHBMSC could synthesize and secrete adherent proteins, which bound to the surface of stromal cells and extracellular matrix.

CONCLUSION

Adherent proteins and all kinds of hematopoietic growth factors secreted by stromal cells constitute a complex network supporting hematopoiesis.

Major origin of mutagenicity of chlorinated drinking water in China: humic acid or pollutants

Since Loper and Glatz (J. Toxicol. Environ. Health, 4:919-938;1978) discovered the presence of the mutagenicity in drinking water after chlorination in 1978, humic acid (HA) has been considered as an important source. But our research results show that only 1/8 of observed direct frameshift mutagenicity in tap water originated from chlorination of HA isolated from raw water. Contamination from industrial waste and human settlement (night soil) are important potential sources of mutagenicity in chlorinated drinking water. The results show that mutagenicity from night soil after chlorination depended upon pH of sample. Production of mutagenicity at pH 6 is ten times of that at pH 8, and decomposition process is necessary condition for mutagenicity production. Season variation of mutagenicity of tap is also presented in the paper.

[An experiment study of reversed pulmonary hypertension with inhaled nitric oxide on smoke inhalation injury]

We evaluated the effect and mechanisms of reversed pulmonary hypertension with inhaled nitric oxide (NO) on smoke inhalation injury in the dog model, 21 dogs were divided into 3 groups randomly. Following smoke inhalation, the control group (n = 8) inhaled O2 (FiO2, 0.45) and the treated group (n = 9) inhaled O2 and 0.0045% (45 ppm) NO. Hemodynamics was serially measured for 12 hours. In addition, 4 dogs without smoke inhalation were used to study the normal lung histomophologic findings. The data were analyzed by ANOVA. After inhalation of NO, the mean pulmonary artery pressure (mPAP), pulmonary minute vessels pressure (Pmv), and pulmonary vascular resistance (PVR) were decreased significantly (P < 0.05), while the mean aortic pressure (mAP) and total peripheral resistance (TRP) were not remarkably changed (P > 0.05). The levels of cyclic guanosine monophosphate (cGMP) were increased significantly (P < 0.01). Inhaled NO may reverse pulmonary hypertension with smoke inhalation injury in dogs. The mechanism of selective pulmonary circulation was increased cGMP level in smooth cells. Inhaled NO may be recommended for clinical application.

Impaired signaling in alloantigen-specific CD8+ T cells tolerized in vivo: employing a model of Ld-specific TCR transgenic mice transplanted with allogenic hearts under the cover of a short-term rapamycin treatment

Peripheral tolerance of T cells is necessary because thymic deletion is not complete, and tissue-specific Ags exist outside the thymus. We have reported that persistent Ag is required to maintain peripheral tolerance in vivo. We suspect that the TCR signaling pathway in in vivo tolerized cells is compromised due to continuous exposure to the Ags. In this study, the TCR signaling events in these cells were investigated using TCR transgenic mice (2C mice) whose T cells are predominantly Ld alloantigen-specific CD8 cells. The 2C mice were thymectomized and then rendered tolerant to Ld Ag by allogenic heart transplantation plus short-term treatment with rapamycin. We found that 1) the in vivo tolerized CD8 cells have compromised intracellular Ca2+ flux upon mitogen stimulation; and 2) their cellular tyrosine proteins fail to be phosphorylated properly upon TCR cross-linking. These results indicate that the signaling pathway in the in vivo tolerized CD8 cells is indeed defective. We also found that 1) the tolerized CD8 cells have no characteristic surface markers; and 2) the allograft is probably the place where the rejection response is initiated according to the appearance of an early activation marker of T cells on graft-infiltrating cells.

Impaired signaling in alloantigen-specific CD8+ T cells tolerized in vivo: employing a model of Ld-specific TCR transgenic mice transplanted with allogenic hearts under the cover of a short-term rapamycin treatment

Peripheral tolerance of T cells is necessary because thymic deletion is not complete, and tissue-specific Ags exist outside the thymus. We have reported that persistent Ag is required to maintain peripheral tolerance in vivo. We suspect that the TCR signaling pathway in in vivo tolerized cells is compromised due to continuous exposure to the Ags. In this study, the TCR signaling events in these cells were investigated using TCR transgenic mice (2C mice) whose T cells are predominantly Ld alloantigen-specific CD8 cells. The 2C mice were thymectomized and then rendered tolerant to Ld Ag by allogenic heart transplantation plus short-term treatment with rapamycin. We found that 1) the in vivo tolerized CD8 cells have compromised intracellular Ca2+ flux upon mitogen stimulation; and 2) their cellular tyrosine proteins fail to be phosphorylated properly upon TCR cross-linking. These results indicate that the signaling pathway in the in vivo tolerized CD8 cells is indeed defective. We also found that 1) the tolerized CD8 cells have no characteristic surface markers; and 2) the allograft is probably the place where the rejection response is initiated according to the appearance of an early activation marker of T cells on graft-infiltrating cells.

Immunosuppressive effects of the cyclosporin derivative SDZ IMM 125 on kidney allograft in the dog and small bowel and pancreas allografts in the rat

The efficacy of SDZ IMM 125 in preventing allograft rejection was evaluated in kidney transplantation in the dog and orthotopic small bowel and heterotopic pancreas transplantation in the rat. Seven groups (n = 6) were involved in dog kidney transplantation. Untreated recipients rejected kidney allografts with a mean survival time (MST) of 8.0 +/- 1.8 days. There was a graded dose response in SDZ IMM 125-treated groups: 10 mg/kg/day, MST 11.3 +/- 3.5 days, P = 0.065; 15 mg/kg/day, MST 44.8 +/- 10.8 days, P = 0.0001; and 20 mg/kg/day, MST 47.3 +/- 5.6 days, P = 0.0001, same as in cyclosporin A (CsA)-treated groups: 10 mg/kg/day, MST 25.8 +/- 13.7 days, P = 0.001; 15 mg/kg/day, MST 38.3 +/- 18.1 days, P = 0.002; and 20 mg/kg/day, MST 38.7 +/- 17.7 days, P = 0.002. Low dose of SDZ IMM 125 (10 mg/kg/day) was less effective in prolonging the graft survival than low dose of CsA. High dose (20 mg/kg/day) treatment of both SDZ IMM 125 and CsA led to abnormal recipient liver enzymes alanine aminotransferase and aspartate aminotransferase postoperatively. A histopathological study demonstrated fatty degeneration of hepatic cells in both 20 mg/kg/day SDZ IMM 125- and CsA-treated groups. We also tested the effect of SDZ IMM 125 in orthotopic small bowel transplantation with three combinations, namely host-versus-graft (HVG), graft-versus-host (GVH), and combined HVG and GVH immune responses and pancreas transplantation in the rat with different doses. The results indicate that SDZ IMM 125 is a potent immunosuppressant to prolong the kidney allograft survival in the dog, to alleviate HVG and GVH responses in small bowel transplantation, and to delay pancreas allograft rejection in the rat. Low dose of SDZ IMM 125 is less effective than a similar dose of CsA to prevent kidney allograft rejection in the dog.

DNA fingerprint variability within and among parental lines and its correlation with performance of F1 laying hens

Genetic diversity within and among nine pure lines of Beijing White Leghorn chickens was determined by DNA fingerprinting using human ministatellite probes 33.6 and α-globin 3'HVR, as well as bacteriophage M13. Within lines similarity coefficients ranged from 0.497 to 0.628, significantly higher than that within a sample of white chicken from a local market. Relationships among lines were established by clustering analysis based on inter-line coefficients of difference calculated from DNA fingerprints of pooled DNA. A complete diallel crossing among the nine pure lines was conducted. By using linear correlation analysis, it was found that the maximum distance between parental lines was positively correlated with egg number, egg production, survival rate and their corresponding heterosis percentages within a pair of reciprocal crosses. Similar relationships were found where only the higher of the reciprocal crosses were used in the analysis. It was also shown that similarity coefficients within a sire line or dam line were positively correlated with 40-week egg number and its heterosis percentage and the heterosis percentage for 40-week egg production, but negatively correlated with the 40-week survival rate of the cross-bred populations.

The immunosuppressive effect of rapamycin on mouse small bowel transplantation

The efficacy of rapamycin (RAPA) was tested on small bowel transplantation in the mouse and compared with cyclosporine (CsA). Four groups were involved, each one included three combinations (n > or = 6) for evaluation of host-versus-graft (HVG, C57BL/6 X BALB/c F1 (CB6F1)-to-BALB/c), graft-versus-host (GVH, BALB/c-to-CB6F1), and combined HVG and GVH responses (C57BL/6-to-BALB/c). Grafts were transplanted to recipients heterotopically. Groups were as follows: group 1: naive controls; groups 2 and 3: recipient mice treated with RAPA 2 mg/kg/day and 4 mg/kg/day orally for 14 days, respectively; group 4: recipient mouse treated with CsA 4 mg/kg/day orally for 14 days. In the HVG model, the mean survival time (MST) of recipients was significantly longer in group 2 (32.9 +/- 17.7 days, P=0.006), group 3 (32.7 +/- 10.4 days, P=0.0001), and group 4 (37.9 +/- 11.8 days, P=0.0001), compared with naive controls in group 1 (8.5 +/- 1.6 days). In the GHV model, the MST of recipients in group 2 (41.8 +/- 19.9 days, P=0.002), group 3 (48.2 +/- 21.4 days, P=0.001) and group 4 (56.5 +/- 30.6 days, P=0.003) were significantly prolonged compared with control group 1 (8.5 +/- 1.6 days). In combined HVG and GVH responses, MST of recipient in group 2 (20.9 +/- 4.9 days, P=0.0001), group 3 (27.0 +/- 4.3 days, P=0.008), and group 4 (35.2 +/- 23.9 days, P=0.0001) were also significantly longer than that in controls (6.9 +/- 1.4 days), but in all three combinations, there were no statistically significant differences between groups 2 and 3, groups 2 and 4, or groups 3 and 4 (P>0.05). RAPA is a potent immunosuppressant able to significantly prolong small bowel allograft survival in mice using a short-term treatment. There is no statistically significant difference in recipient survival between low and high doses of RAPA treatment and the CsA standard dose used in this study.

Laser Raman spectrometry study on experimental galactose-induced cataract

PURPOSE

To observe the dynamic changes of hydration in galactose induced cataract.

METHODS

Two groups of Wistar rats were used in the experiment. There were 12 rats in the experimental group, which were fed diet of 50% D-Galactose standard feed; while the control group had 8 rats fed standard feed. Their other living conditions were the same. At desired time periods, two Wistar rats fed galactose and one normal control were selected and killed 20 minutes before the instrument examination respectively, then, their lenses were removed from the orbs by a posterior approach. The cleaned fresh lens was placed in a quartz cuvette with Tris buffered balanced salt solution containing 5.5 mmol/L glucose. The quartz cuvette was placed on the stage of the Spectrometer. The laser beam was focused at the lens nuclear from the bottom of the cuvette and the scattered light was collected at 90 degrees to the incident beam.

RESULTS

Raman spectroscopy showed that (1) during the formation of galactose cataract, the water signal (at 3390cm-1) increased obviously, and the ratio of I3390/I2935 increased from 0.31 (3 days) to 2.26 (17 days), which is correlated with the imbibition of water in the lens nuclear; (2) the hydration of lens nuclear could be divided into two phases. The ratio I3390/I2935 was increased slowly and steadily by 11 days after galactose feeding. Then, the ratio turned to increase quite fast till 17 days.

CONCLUSION

The hydration of nuclear is changed simultaneously with the formation of cataract. The hydration of nuclear is mainly due to the imbalance of Na+/K+.

[The significance of high-density lipoprotein subfractions and triglycerides in predicting coronary artery disease]

Serum Lipid profiles, including high-density lipoprotein (HDL) and its subfractions HDL2 and HDL3 were obtained in 78 cases undergoing coronary angiography. Coronary artery disease (CAD) was present in 51 patients and absent in 27. We used a scoring methold of CAD to reflect the extent or narrowing of coronary artery. The largest difference between the two groups was observed in HDL2 Cholesterol with a mean of 0.37 mmol/L in patients with CAD as compared with 0.49 mmol/L in normal subjects (P < 0.001) and in TG (1.85 mmol/L vs 1.16 mmol/L) as well. Smaller difference was found in TC (5.9 mmol/L vs 4.87 mmol/L, P < 0.05). No singnificant difference was found in serum HDL (P > 0.05). Multivariate regression analysis revealed that the most powerful indenpendent variable associated with the extent of CAD was HDL2 cholesterol and triglyceride. The score of CAD was significantly correlated with HDL2-c (r = 0.32 P < 0.01) and TG (r = 0.34 P < 0.01). It is shown that high serum level of TG (> 1.6 mmol/L) and low serum level of HDLC2 (< 0.37 mmol/L) were the strengest predictors of presence and extent of CAD.

Rapamycin graft pretreatment in small bowel and kidney transplantation in the rat

The effect of rapamycin (RAPA) as graft pretreatment was evaluated in orthotopic small bowel and kidney allotransplantation (Tx) in the rat. In the small bowel Tx model, six groups were involved, each including three combinations for evaluation of host-versus-graft (HVG) [Lewis (LEW) x Brown Norway (BN) (LBN)-F1-->Lewis], graft-versus-host (GVH) (LEW-->F1), and combined HVG and GVH immune responses (BN-->LEW). RAPA graft pretreatment alone (16 micrograms/ml x 3 ml) was able to induce a modest but significant prolongation of survival in all three combination models compared with controls (P < 0.05). The same was observed for low dose CsA treatment (2 mg/kg/day x 14 days) of the recipient only (P < 0.05). Combination of graft pretreatment with RAPA and CsA recipient treatment produced a marked prolongation of survival especially in HVG response. Recipients treatment with one 48-microgram bolus of RAPA i.v. immediately after graft revascularization failed to achieve any prolongation of survival for the GVH or combined HVG and GVH responses. This seems to exclude a "carry-over" effect of RAPA from graft to recipient. RAPA efficacy was also clearly confirmed in the kidney graft pretreatment model as compared to recipient treatment with an equivalent RAPA dose. These results demonstrate that graft RAPA pretreatment prolongs SB survival after Tx in the rat for HVG, GVH, and bidirectional immune responses. Intragraft interaction with passenger leukocytes or APC function appears as one of the possible mechanisms. RAPA graft pretreatment potentiates low dose CsA recipient treatment suggesting a possible use in clinical organ Tx.

Purity control of different bee venom melittin preparations by capillary zone electrophoresis

A rapid capillary zone electrophoresis method was developed for the determination of melittin during its purification from bee venom by column chromatography. Low-pH buffer was selected to decrease the adsorption of the analytes on capillary wall. The average relative standard deviations of the migration time of melittin and of the peak area were 1.2 and 2.3%, respectively.

Islet cell DNA is a target of inflammatory attack by nitric oxide

NO has been identified recently as the prime islet-toxic product of inflammatory macrophages. The adverse effects of IL-1 on isolated islets also have been reported to involve NO. We now show that exposure of an islet cell suspension to the NO donor nitroprusside or to activated macrophages leads to DNA strand breaks. Macrophages did not induce DNA damage in the presence of the NO synthase inhibitor NG-methyl-L-arginine. DNA strand breaks were demonstrated at the level of single cells by a modified nick-translation procedure and confirmed by analysis of DNA fragmentation by gel electrophoresis. DNA strand breaks occurred within 1 h and preceded islet cell lysis. DNA damage could not be prevented by inhibitors of endogenous endonucleases. We conclude that islet cell DNA is an early target of NO action.

Genomic dispersal of the ets gene family during metazoan evolution

Evolutionary homologs of the ets proto-oncogene have been discovered in the genomes of widely divergent eucaryote species from Drosophila to sea urchin to vertebrates. The prototype mammalian ets-1 and ets-2 genes are divided into three coding domains that differ in their rate of accumulation of sequence divergence. An analysis of sequence divergence of ets gene homologs in various species has produced a phylogenetic history of the ets gene family in the context of metazoan evolutionary radiation. A minimum of five duplication events of ets primordial genes were evident, namely (1) a duplication that separates primitive ets genes (Drosophila precursor of 74E, mouse PU.1 and human ELK1) from the ets-1, ets-2, erg ancestor; (2) and (3) two duplications that established separate ets, erg and elg/GABP-alpha lineages which occurred prior to invertebrate-vertebrate divergence; (4) divergence of ets-1 and ets-2 gene family also associated with vertebrate-invertebrate divergence; (5) duplication of ets-1 and ets-2 in Xenopus laevis to produce two ets-1 genes and two ets-2 genes during genomic tetraploidation in the recent ancestry of this species.

[Relationship between various stromal cells in long-term bone marrow culture]

In the present studies, the relationship and special junctions between various stromal cells in long term bone marrow culture were reported. The possible significance of these signs vis-a-vis the hemopoietic microenvironment were discussed. Fibronectin and thrombospondin were detected on the substratum and surface of the stromal cells using immunogold techniques. These adhesion proteins on the stromal cells might be important in cell-cell and cell-stroma connection.

Human papillomavirus 16 DNA immortalizes two types of normal human epithelial cells of the uterine cervix

Premalignant cervical lesions occur at the squamo-columnar junction and in endocervical epithelium and squamous ectocervical epithelium, in descending order of frequency. However, previously only ectocervical cells have been clearly shown to be immortalized in vitro by the oncogenic human papillomaviruses (HPVs). This report describes the immortalization of normal human ecto- and endocervical epithelial cells by the intact HPV 16 genome. Ectocervical epithelial cells (HEC) became immortalized (HEC-16) without crisis while endocervical cells (HEN) were immortalized (HEN-16) after undergoing crisis. HEN-16 and HEC-16 contained integrated HPV 16 DNA, expressed E6 and E7 mRNA, and were aneuploid and nontumorigenic. They also expressed cytokeratins in a pattern similar to their distinct normal parental cells. These results suggest that both squamous and simple epithelial cells of uterine cervix are targets for immortalization by HPV 16.

The sea urchin erg homolog defines a highly conserved erg-specific domain

A genomic clone, isolated from a phage library prepared from the DNA of the sea urchin Lytechinus variegatus, was shown by sequence analysis to be a homolog of the ets family genes, ERG and Fli-1. It contains an open reading frame of which the coding region begins at a consensus 3' splice site and extends for 173 amino acid residues. The first 84 amino acids are homologous with all members of the ets gene family, while the remainder of the sequence is only homologous with the human ERG and murine Fli-1 genes. This latter region, designated R, represents a highly conserved erg-specific domain.