[The identification of Hippocampus by HPCE]

Hippocampus from various origins were identified by HPCE. And their character spectrums were established.

The acetylcholine release enhancer linopirdine induces Fos in neocortex of aged rats

Centrally acting cholinergic agents induce the immediate early gene c-fos in the rat brain resulting in transient increases of Fos protein, most notably in the cerebral cortex. In this study we have monitored by Fos immunohistochemistry the effect of the acetylcholine release enhancer linopirdine (DUP996) on the immediate early gene c-fos in brains of 3 months and 30 months old rats. In young rats linopirdine had only a marginal effect on Fos expression. In contrast, in aged rats linopirdine caused widespread expression of Fos throughout neocortex. In somatosensory cortex, the induction of the c-fos gene by linopirdine was nearly completely blocked by atropine and scopolamine and strongly attenuated by the NMDA receptor blockers CPP and MK-801. The results suggest that the age-related decline in acetylcholine release in rodents can be partially compensated for by administration of linopirdine.

[Morphological and histological studies of herba sedum aizoon]

The description characters of Herba Sedum aizoon were recounted. And the histological characters of the root, rhizome, stem, leaf and flower of the plant were reported. The characters of the isolated tissue and powder were also involved. These results provided valuable reference information for putting the medicinal resource to rational exploitage and use.

Use of suppression subtractive hybridization for differential gene expression in stroke: discovery of CD44 gene expression and localization in permanent focal stroke in rats

BACKGROUND AND PURPOSE

CD44 is a transmembrane glycoprotein involved in endothelial cell recognition, lymphocyte trafficking, and regulation of cytokine gene expression in inflammatory diseases. The present report describes the discovery of upregulated CD44 gene expression and its spatial and temporal distribution in the brain after focal stroke.

METHODS

Rats were subjected to permanent occlusion of the middle cerebral artery (MCAO). Suppression subtractive hybridization (SSH) strategy was used to identify differentially expressed genes. Northern blotting and real-time polymerase chain reaction were used to evaluate the expression of CD44 and hyaluronan synthase 2 (HAS-2) mRNA. Western blotting and immunohistochemistry were used to examine CD44 expression and cellular distribution.

RESULTS

CD44 upregulation after focal stroke was discovered by the SSH approach and confirmed by DNA sequencing. Northern blot using a pooled poly(A)+ RNA revealed 3 splice variants of CD44 mRNA, and their inducible expression started at 6 hours (5.3-fold increase over sham operation), peaked at 24 hours (28.6-fold increase), and persisted up to 72 hours (17.8-fold increase) after MCAO. A parallel induction profile of HAS-2 mRNA was observed in the ischemic brain tissue. The levels of CD44 were markedly elevated at 6 hours (1.8-fold increase over sham; n=3), 24 hours (2.9-fold, peak induction; P<0.01), and 72 hours (2.4-fold increase; P<0.05) after MCAO by means of Western analysis. Immunohistochemical and confocal microscopy confirmed that constitutive expression of CD44 is limited to microvessels in normal brain but is strongly induced after ischemia, where the immunoreactive signal mainly resided in endothelial cells and monocytes. Double-labeling immunohistochemistry demonstrated that a marked induction of CD44 in the ischemic lesion is dominantly located in microglia and a subset of macrophages.

CONCLUSIONS

The discovery of concomitant induction of CD44 and HAS-2 mRNA expression and the localization of CD44 in the microglia, macrophages, and microvessels of the ischemic brain tissue suggest that an active interaction between CD44 and hyaluronan may occur and play a role in the known inflammatory response and tissue remodeling after stroke.

5-[I-125/123]lodo-3(2(S)-azetidinylmethoxy)pyridine, a radioiodinated analog of A-85380 for in vivo studies of central nicotinic acetylcholine receptors

The in vivo biodistribution profile of the novel nicotinic acetylcholine receptor (nAChR) radioligand 5-[I-125/123]Iodo-3(2(S)-azetidinylmethoxy)pyridine, [I-125/123]-5-IA, in mouse brain was examined. This radiotracer displayed good brain penetration (3.1% of the injected dose (ID) in whole brain at 15 min post-radioligand injection). Radioligand distribution was consistent with the density of high affinity nAChRs with highest uptake observed in the nAChR-rich thalamus (14.9 %ID/g at 60 min), moderate uptake in cortex (8.5 %ID/g at 60 min), and lowest uptake in the cerebellum (2.4 %ID/g at 60 min). Pretreatment with several different nAChR agonists (A-85380, (-)-nicotine, cytisine) significantly inhibited [I-125]-5-IA binding in all brain regions studied (P < 0.01) demonstrating the high specificity of the radioligand for nAChRs. Blocking doses of the muscarinic antagonist scopolamine and the non-competitive nAChR channel blocker mecamylamine had no significant effect on radioactive uptake supporting the in vitro selectivity of [I-125]-5-IA for the nAChR component of the cholinergic system. [I-125]-5-IA binding sites were shown to be saturable with unlabeled 5-IA. With a relatively low acute toxicity (LD50 > 3 mg/kg via intravenous injection in mice) and high in vivo specificity and selectivity, 5-IA labeled with the imaging radionuclide I-123 may prove useful for single photon emission computed tomography (SPECT) studies of nAChRs in human subjects.

Protection of xenografts by a combination of immunoisolation and a single dose of anti-CD4 antibody

Immunoisolation is the separation of transplanted cells from cells of the immune system using a semipermeable membrane. Using one such immunoisolation capsule-the TheraCyte device-we have assessed the survival of encapsulated xenogeneic tissue in vivo as well as the contribution of CD4+ve T cells to encapsulated xenograft rejection. The foreign body reaction to the TheraCyte capsule in vivo was assessed by transplanting empty capsules into normal mice. These capsules elicit a foreign body response by the host animal. Encapsulated CHO, NIT-1, and PK-15 cells were placed in culture and in immunodeficient mice to investigate their growth characteristics in the TheraCyte device. These cell lines survive both in culture and in immunodeficient SCID mice. Xenogeneic PK cells were also transplanted into normal C57BL/6 mice. These cells do not survive in normal mice despite the absence of direct contact between infiltrating and encapsulated cells. In addition, the survival of encapsulated cells in mice treated with a single dose of anti-CD4 antibody was examined. This was assessed using two systems: 1) histological analysis of capsule sections; 2) a quantitative luciferase reporter system using PK cells transfected to express luciferase. In both cases, anti-CD4 antibody contributed to prolonged encapsulated xenogeneic cell survival. Encapsulated xenogeneic cells survive in immunodeficient mice but not normal mice. Treatment of normal mice with anti-CD4 antibody results in prolonged survival of xenogeneic cells that can be measured using a luciferase reporter system. These results highlight the contribution of CD4+ve T cells to encapsulated xenograft rejection.

Effects of combination of ACE inhibitor and angiotensin receptor blocker on cardiac remodeling, cardiac function, and survival in rat heart failure

BACKGROUND

The mechanism and treatment of diastolic heart failure are poorly understood. We compared the effects of an ACE inhibitor, an angiotensin receptor blocker (ARB), and their combination on diastolic heart failure in Dahl salt-sensitive (DS) rats.

METHODS AND RESULTS

DS rats fed an 8% NaCl diet from 7 weeks of age were treated with benazepril 10 mg/kg alone, valsartan 30 mg/kg alone, or combined benazepril and valsartan at 5 and 15 mg/kg, respectively, or at 1 and 3 mg/kg, respectively. At 16 weeks of age, DS rats exhibited prominent concentric left ventricular (LV) hypertrophy and diastolic dysfunction with preserved systolic function, as estimated by echocardiography. Despite comparable hypotensive effects among all drug treatments, the combination of benazepril 5 mg/kg and valsartan 15 mg/kg improved diastolic dysfunction and survival in DS rats more effectively than ACE inhibitor or ARB alone. Furthermore, the increase in LV endothelin-1 levels and hydroxyproline contents in DS rats was significantly suppressed only by combined benazepril and valsartan, and LV atrial natriuretic peptide mRNA upregulation in DS rats was suppressed to a greater extent by the combination therapy than monotherapy.

CONCLUSIONS

The combination of ACE inhibitor and ARB, independently of the hypotensive effect, improved LV phenotypic change and increased LV endothelin-1 production and collagen accumulation, diastolic dysfunction, and survival in a rat heart failure model more effectively than either agent alone, thereby providing solid experimental evidence that the combination of these 2 agents is more beneficial than monotherapy for treatment of heart failure.

The development, maturation, and turnover rate of mouse spleen dendritic cell populations

Three distinct subtypes of dendritic cells (DC) are present in mouse spleen, separable as CD4(-)8alpha(-), CD4(+)8alpha(-), and CD4(-)8alpha(+) DC. We have tested whether these represent stages of development or activation within one DC lineage, or whether they represent separate DC lineages. All three DC subtypes appear relatively mature by many criteria, but all retain a capacity to phagocytose particulate material in vivo. Although further maturation or activation could be induced by bacterially derived stimuli, phagocytic capacity was retained, and no DC subtype was converted to the other. Continuous elimination of CD4(+)8(-) DC by Ab depletion had no effect on the levels of the other DC subtypes. Bromodeoxyuridine labeling experiments indicated that all three DC subtypes have a rapid turnover (half-life, 1.5-2.9 days) in the spleen, with none being the precursor of another. The three DC subtypes showed different kinetics of development from bone marrow precursors. The CD8alpha(+) spleen DC, apparently the most mature, displayed an extremely rapid turnover based on bromodeoxyuridine uptake and the fastest generation from bone marrow precursors. In conclusion, the three splenic DC subtypes behave as rapidly turning over products of three independent developmental streams.

Positive-negative epitope-tagging of beta amyloid precursor protein to identify inhibitors of A beta processing

In this report, a novel positive-negative epitope tagging approach was developed to study the cellular processing of beta amyloid precursor protein (beta APP). Amino acids centered around the alpha-secretase cleavage site within the A beta sequence were replaced with residues comprising an epitope for which high-affinity monoclonal antibodies are commercially available. The resulting mutant beta APP cDNAs were expressed in human embryonic kidney cells (HEK 293). Cleavage of labeled beta APP by beta- and gamma-secretase(s) results in the release of an epitope-tagged A beta peptide, whereas cleavage by alpha-secretase results in destruction of the epitope. Highly sensitive and specific immunoassays were developed to study processing of this labeled beta APP via the amyloidogenic pathway. Secretion of epitope-tagged A beta was prevented by MDL 28170, a previously described gamma-secretase inhibitor. Confocal microscopic studies revealed that processing and cellular trafficking of epitope-tagged beta APP was not different from wild-type beta APP. These results suggest that positive-negative epitope-tagged beta APP is normally processed within the cell and may be used to identify secretase inhibitors as therapeutics for Alzheimer's disease.

In vivo activation of rat aortic platelet-derived growth factor and epidermal growth factor receptors by angiotensin II and hypertension

It is unclear whether the previous in vitro evidence of a link between angiotensin II (Ang II) and growth factor receptors can apply to the in vivo situation. In this study, we examined vascular platelet-derived growth factor (PDGF) and epidermal growth factor (EGF) receptor activation in stroke-prone spontaneously hypertensive rats (SHRSP) and the role of Ang II. Tyrosyl phosphorylation of the growth factor receptors was determined by Western blot analysis coupled with immunoprecipitation. Tyrosyl phosphorylation of the aortic PDGF beta-receptor, but not the EGF receptor, was chronically increased in SHRSP with hypertension, compared with normotensive rats, being accompanied by increased extracellular signal-regulated kinase (ERK) activity. Treatment of SHRSP with ACE inhibitors (perindopril or enalapril) significantly reduced aortic PDGF beta-receptor tyrosyl phosphorylation and ERK activity, whereas treatment with hydralazine failed to reduce these activities. Therefore, these aortic changes in SHRSP were mediated by Ang II in response to vascular ACE. Ang II was infused into rats to examine the effects on aortic growth factor receptors. Chronic Ang II infusion, via the angiotensin type 1 receptor, significantly increased activation of the aortic PDGF beta-receptor but not the EGF receptor. Thus, the aortic PDGF beta-receptor, activated by ACE-mediated Ang II, seems to be responsible for vascular remodeling in hypertensive rats.

Predominant transgene expression in exocrine pancreas directed by the CMV promoter

The enhancer/promoter of the human cytomegalovirus gene encoding the major immediate-early protein (CMVp) is reputed to be one of the strongest and most promiscuous regulatory elements for directing transcription of heterologous genes in vitro. However, transgene expression under the promoter in adult transgenic mice is often more restricted. We selected a CMVp segment from position -350 to +59 to control expression of transgenes for two secretory fusion proteins. Expression was analyzed by immunohistology staining and quantified by Northern blot, Western blot, and ELISA of secretions from explanted tissues. In all six lines of transgenic mice, the highest expression of transgenes at the mRNA and protein level was observed in the exocrine tissue of the pancreas, although the levels of expression varied among the lines. The results indicate not only that CMVp is not a universal promoter in vivo but indeed that it can be relatively specific for the exocrine pancreas, where expression of the gene it controlled was consistently very high.

Transgenic anti-CD4 monoclonal antibody secretion by mouse segmental pancreas allografts promotes long term survival

To compare the effectiveness of transgenic and systemic monoclonal antibody therapy for pancreas transplantation, vascularised segmental pancreas allografts from wild-type or transgenic pancreatic tissue that secreted monoclonal anti-CD4 were placed in CBA recipients in which diabetes had been induced chemically by streptozotocin (STZ, non-autoimmune diabetes). In untreated CBA recipients, wild-type BALB/c or C57BL/6 bml pancreas transplants were rejected in a mean survival time (MST) of 27 and 30 days, respectively. BALB/c and C57BL/6 graft survival improved when recipients were given a short course of T cell depleting monoclonal anti-CD4 antibody, (GK 1.5, 2 mg total on days -1, 0, 1, 2 with grafting on day 0) with MST +/- S.D. of 71 +/- 29 and 44 +/- 36 days, respectively. Thus, transient depletion of CD4 was effective in delaying pancreas allograft rejection in these strain combinations. The use of C57BL/6 bml mice transgenic for a rat anti-CD4 antibody (GK5 mice) as pancreas donors provided allografts that secreted sufficient anti-CD4 antibody to cause CD4 T cell depletion in the recipients (CD4 cells decreased from 30 to < 5% of small lymphocytes). This degree of depletion was not sustained and the CD4 recovery inversely correlated with graft survival. Mice with > 20% CD4 cells in the splenic lymphocyte population 4 weeks post-transplant rejected their grafts (3 of 10 mice). However, in 7 of 10 mice CD4 cells remained low (< 15%) and allografts survived for > 80 days. The GK5 allografts survived significantly longer than those from non-transgenic bml controls (MST 83 +/- 32 days, compared with 30 days, P < 0.0005). This survival time was similar to that of BALB/c allografts in CBA recipients treated with a high dose of anti-CD4 antibody. Thus, transgenic secretion of anti-CD4 antibody by the pancreas allograft was very effective in prolonging its survival.

Murine hematopoietic stem cell characterization and its regulation in BM transplantation

Using 5-color fluorescence-activated cell sorting, we isolated a subset of murine pluripotent hematopoietic stem cells (PHSC) with the phenotype Lin(-) Sca(+) kit(+) CD38(+) CD34(-) that appears to fulfill the criteria for most primitive PHSC. In the presence of whole bone marrow (BM) competitor cells, these cells produced reconstitution in lethally irradiated primary, secondary, and tertiary murine transplant recipients over the long term. However, these cells alone could not produce reconstitution in lethally irradiated recipients. Rapid proliferation of these cells after BM transplantation required the assistance of another BM cell subset, which has the phenotype Lin(-) Sca(+) kit(+) CD38(-) CD34(+).

Delayed rejection of fetal pig pancreas in CD4 cell deficient mice was correlated with residual helper activity

CD4 cells have been shown to play a dominant role in the rejection of xenografts. Depletion of murine CD4 cells by injecting anti-CD4 antibody prolongs the graft survival, but does not prevent its rejection. For a more stable phenotype, we used genetically modified mice. To test whether the delayed rejection is caused by incomplete depletion of CD4 cells, we evaluated the response to fetal pig pancreas (FPP) xenografts in three types of CD4 cell deficient mice. They are MHC class II deficient mice (MHC II(o/o), CD4 deficient mice (CD4(o/o)) and a novel type of CD4 cell deficient mice (designated GK). GK mice were rendered permanently and completely CD4 deficient by transgenic expression of anti-CD4 antibody, whereas both MHC II(o/o) and CD4(o/o) mice have a residual helper cell population. FPP grafts in wild type mice were rejected within a week, whereas FPP grafts survived up to 4 weeks in MHC II(o/o) and CD4(o/o) mice. Survival of grafts in GK mice was even longer (8 weeks). Differences in histology were also noted. Rejecting grafts in MHC II(o/o) and wild-type mice were infiltrated with both eosinophils and mononuclear cells, whereas the infiltrates in CD4(o/o) and GK mice were exclusively mononuclear cells. Immunohistochemistry showed that they were primarily CD8 cells. The immune response to FPP was clearly different in the three types of CD4 cell deficient mice. Splenocytes of MHC II(o/o) 3 weeks post-transplant with FPP produced substantial amounts of IFN-gamma and IL-5, whereas splenocytes of CD4(o/o) mice produced low levels of IFN-gamma but no detectable IL-5. At similar times, these cytokines were not detected in GK mice. Furthermore, CD4(o/o) mice were capable of mounting helper dependent, although reduced, IgG responses to FPP antigens, while GK mice were not. The above results indicate that residual helper activity in some types of CD4 cell deficient mice could still contribute to xenograft rejection. Caution needs to be exercised where such mice are used as models of CD4 cell deficiency. Also, because there is eventual rejection of xenograft FPP in GK mice which lack detectable helper activity, we argue that these mice are a better model to investigate the involvement of CD4-independent rejection mechanisms.

CD4 help-independent induction of cytotoxic CD8 cells to allogeneic P815 tumor cells is absolutely dependent on costimulation

Mice made transgenic (Tg) for a rat anti-mouse CD4 Ab (GK mice) represent a novel CD4-deficient model. They not only lack canonical CD4 cells in the periphery, but also lack the residual aberrant Th cells that are found in CD4-/- mice and MHC class II-/- mice. To analyze the role of CD4 help and costimulation for CTL induction against alloantigens, we have assessed the surface and functional phenotype of CD8 cells in vivo (e.g., clearance of allogeneic P815 cells) and in vitro. In our CD4-deficient GK mice, CTL responses to allogeneic P815 cells were induced, albeit delayed, and were sufficient to eliminate P815 cells. Induction of CTL and elimination of allogeneic P815 cells were inhibited both in the presence and absence of CD4 cells by temporary CD40 ligand blockade. This indicated that direct interaction of CD40/CD40L between APCs and CD8 cells may be an accessory signal in CTL induction (as well as the indirect pathway via APC/CD4 interaction). Furthermore, whereas in CTLA4Ig single Tg mice P815 cells were rejected promptly, in the double Tg GK/CTLA4Ig mice CTL were not induced and allogeneic P815 cells were not rejected. These findings suggest that CD40/CD40L is involved in both CD4-dependent and CD4-independent pathways, and that B7/CD28 is pivotal in the CD4-independent pathway of CTL induction against allogeneic P815 cells.

[Characterization of the Pt/CeO2-ZrO2/Al2O3 catalysts by spectra]

The performance of Pt/Al2O3 catalysts with CeO2-ZrO2 in difference ways was studied by NIR-FT-Raman, BET, H2 chemisorption, XRD. It shows that the dispersion of Pt on Al2O3 is improved with the increasing of dispersion of CeO2-ZrO2 on the surface of Al2O3, owing to the strong interacting between CeO2-ZrO2 and Pt. And adding with salts is priority.

Effects of angiotensin II receptor blockade on hepatic fibrosis in rats

OBJECTIVE

To investigate the effects of angiotensin II type 1 receptor blockade, losartan, on serum levels of components of extracellular matrix in experimental fibrotic rats.

METHODS

Fifty male Spague-Dawley rats were separated into five groups (control, model, and 3 treatment groups). Excepting rats in control group, all rats were given subcutaneous injection of 40% carbon tetrachloride (once every 3 days for 6 weeks). Rats in 3 treatment groups were also given losartan of 10mg/kg, 5mg/kg, 2.5mg/kg daily for 6 weeks via gastrogavage, respectively. At the end of sixth week, all rats were sacrificed. Radioimmunoassay was performed to determine the serum levels of hyaluronic acid (HA), Laminin (LN), procollagen type III (PCIII) and collagen type IV. Van Giesion collagen staining was used to evaluate the extracellular matrix of the liver tissue.

RESULTS

Compared with model group, losartan significantly reduced the serum levels of HA [from (911.66 +/- 345.49)microg/L to (425.05 +/- 115.80)microg/L], LN [from (209.87 +/- 91.57)microg/L to (83.56 +/- 22.12)microg/L, PCIII [from (31.82 +/- 6.90)microg/L to (22.78 +/- 8.38)microg/L] and collagen IV [from (54.09 +/- 19.81)microg/L to (30.51 +/- 12.39)microg/L] (P<0.05) and greatly attenuated the degree of liver fibrosis (P<0.05).

CONCLUSION

Losartan can markedly reduce the serum levels of LN, HA, PCIII and collagen type IV of fibrotic rats induced by CCl(4) and greatly attenuate the degree of liver fibrosis.

Important role of angiotensin II-mediated c-Jun NH(2)-terminal kinase activation in cardiac hypertrophy in hypertensive rats

In vitro studies on the role of the mitogen-activated protein (MAP) kinase family (extracellular signal-regulated kinase [ERK], c-Jun NH(2)-terminal kinase [JNK], and p38) in cardiac hypertrophic response have produced confusing and contradictory results. We examined the in vivo role of the angiotensin II type 1 (AT(1)) receptor in cardiac MAP kinase activities during both the onset and development of cardiac hypertrophy in stroke-prone spontaneously hypertensive rats (SHRSP). In both the acute and chronic phases of cardiac hypertrophy in SHRSP, cardiac JNK activities were significantly increased compared with those in normotensive rats, whereas there was no prominent increase in cardiac ERK or p38 activities in SHRSP. Losartan, an AT(1) receptor antagonist, prevented the onset of cardiac hypertrophy and regressed the progression of cardiac hypertrophy in SHRSP, being accompanied by the reduction of JNK activity and activator protein-1 (AP-1) activity in SHRSP. However, in spite of the normalization of blood pressure, hydralazine did not prevent or regress cardiac hypertrophy and did not decrease JNK or AP-1 activity in SHRSP. Inversely, hydralazine significantly increased the cardiac ERK activity in SHRSP by enhancing its phosphorylation. In conclusion, we have obtained the first evidence that the AT(1) receptor is involved in the enhanced cardiac JNK activity in both the onset and development of cardiac hypertrophy of hypertensive rats. We propose that JNK is involved in AT(1) receptor-mediated cardiac hypertrophy in vivo, in part mediated by the activation of AP-1.

Local production of anti-CD4 antibody by transgenic allogeneic grafts affords partial protection

BACKGROUND

Immunosuppressive drugs and anti-lymphocyte antibody are used clinically to suppress cellular rejection responses. However, these systemic regimens often led to general immunodeficiency and thus increased susceptibility to opportunistic infection and neoplasia. Immunosuppressive molecules delivered locally may be a way of inhibiting rejection responses, whereas systemic immunity is preserved. To achieve protective local immunosuppression, we produced a graft secreting its own immunomodulator, by deriving transgenic mice expressing a chimeric anti-CD4 antibody (GK2c) in the pancreas.

METHODS AND RESULTS

Transgenic mice in bml genetic background expressing a modified anti-mouse CD4 antibody (GK2c) under two promoters have been produced. Tissue expression of GK2c was detected by immunoperoxidase staining. Under the cytomegalovirus promoter, there was abundant GK2c expression in pancreatic exocrine tissue. Under the rat preproinsulin II promoter, there was abundant GK2c expression in pancreatic endocrine tissue only. High-expression transgenic lines had 10-100 microg/ml GK2c in blood plasma. By flow cytometry, these transgenic mice were devoid of CD4+ cells in their peripheral lymphoid organs. To test transgenic mice as donors, fetal pancreata from transgenic mice were grafted into fully allogeneic CBA mice under the kidney capsule, transgenic grafts had prolonged survival compared with control non-transgenic grafts. Furthermore, GK2c transgenic grafts had reduced infiltration with an absence of CD4+ cells at the graft site without any effect on the cell composition in lymphatic tissues.

CONCLUSION

Transgenic grafts that secrete anti-CD4 antibody can afford some protection against graft rejection, while only affecting the CD4 population at the graft site.

T lymphocytes from granulocyte colony-stimulating factor-/- mice produce large quantities of interferon-gamma in a chronic infection model

Little is known about the role of granulocyte colony-stimulating factor (G-CSF) in the response to chronic bacterial infections. To address this we infected G-CSF knock out (G-CSF-/-) mice with Mycobacterium avium. Infection was not exacerbated in G-CSF-/- mice despite a deficiency in the total bone marrow cells, colony-forming haemopoietic cells, granulocytes and monocyte precursors in the bone marrow. Peritoneal cells from G-CSF-/- produced less nitric oxide (NO) upon culture in vitro with antigen than did wild-type (WT) cells. Unexpectedly, T cells from infected G-CSF-/- mice were able to produce significantly more interferon-gamma (IFN-gamma) than the wild type (WT) controls. T cells from G-CSF-/- mice still produced more IFN-gamma even when in vitro NO production was inhibited, while enzyme-linked immunospot assay (ELISPOT) assays showed more IFN-gamma-producing cells in the G-CSF-/- mice. This was confirmed by intracellular cytokine staining (ICCS), which showed that there were more IFN-gamma producing T cells in vivo in the G-CSF-/- than the WT controls following M. avium infection. It is possible that a deficit of NO in vivo allows T cells to develop a higher IFN-gamma-producing phenotype. Thus we show a novel relationship between G-CSF and IFN-gamma production by T cells revealed in this chronic bacterial infection model.

Prolonged allograft survival in anti-CD4 antibody transgenic mice: lack of residual helper T cells compared with other CD4-deficient mice

BACKGROUND

Investigations of the role of CD4 T lymphocytes in allograft rejection and tolerance have relied on the use of mouse models with a deficiency in CD4 cells. However, in mice treated with depleting monoclonal antibody (mAb) and in MHC class II knockout (KO) mice, there are residual populations of CD4 cells. CD4 KO mice had increased CD4- CD8-TCRalphabeta+ helper T cells, and both strains of KO mice could reject skin allografts at the normal rate. In this study, transgenic mice with no peripheral CD4 cells were the recipients of skin and heart allografts. Results were compared with allograft survival in CD4 and MHC class II KO mice.

METHODS

GK5 (C57BL/6 bml mice transgenic for a chimeric anti-CD4 antibody) had no peripheral CD4 cells. These mice, and CD4 and class II KO mice, received BALB/c or CBA skin or cardiac allografts. Some GK5 mice were treated with anti-CD8 mAb to investigate the role of CD8 cells in rejection. CD4 and CD8 cells were assessed by FACS and immunohistochemistry.

RESULTS

BALB/c skin on GK5 mice had a mean survival time +/- SD of 24+/-6 days, compared with 9+/-2 days in wild-type mice. Anti-CD8 mAb prolonged this to 66+/-7 days. BALB/c skin survived 10+/-2 days on class II KO and 14+/-2 days on CD4 KO, both significantly less than the survival seen on GK5 recipients (P<0.001). BALB/c hearts survived >100 days in GK5 recipients and in wild-type recipients treated with anti-CD4 mAb at the time of grafting, in contrast to a mean survival time of 10+/-2 days in untreated wild-type mice. Immunohistochemistry revealed that long-term surviving heart allografts from the GK5 recipients had CD8 but no CD4 cellular infiltrate. These hearts showed evidence of transplant vasculopathy.

CONCLUSIONS

The GK5 mice, with a complete absence of peripheral CD4 cells, provide the cleanest available model for investigating the role of CD4 lymphocytes in allograft rejection. Prolonged skin allograft survival in these mice compared with CD4 and MHC class II KO recipients was clearly the result of improved CD4 depletion. Nevertheless, skin allograft rejection, heart allograft infiltration, and vascular disease, mediated by CD8 cells, developed in the absence of peripheral CD4 T cells.

Emodin on hepatic fibrosis in rats

OBJECTIVE

To investigate effect of emodin on hepatic fibrosis in rats.

METHODS

The rat hepatic fibrosis model was induced by the subcutaneous injection of 40% CCl4 (twice a week for 6 weeks) dissolved in olive oil. The emodin-treated rats were treated with low-dose, mediate-dose and high-dose emodin (20, 40 and 80 mg/kg body weight, once a day for 42 days) dissolved in 0.5% sodium carboxymethylcellulose (CMC), except receiving CCl4. Control group received only olive oil and 0.5% CMC. Liver functions were determined by standard procedure. Serum hyaluronic acid and laminin were determined by radioimmunoassay. Liver hydroxyprolines were determined. Histopathological changes were examined by optical microscopy.

RESULTS

Compared with model group, the emodin-treated rats showed (1) liver functions were improved, alanine transaminase (ALT) and alkaline phosphatase (AKP) were obviously reduced, and total protein (TP) and albumin (ALB) were significantly increased; (2) serum hyaluronic acid and laminin were markedly reduced; (3) liver hydroxyproline was significantly decreased; (4) the degrees of fibrosis were reduced. The changes of parameters mentioned above were significant (P < 0.05 or P < 0.01).

CONCLUSION

Emodin has effect on hepatic fibrosis in rats. The hepatoprotective of emodin may be one of mechanisms for liver fibrosis.

[Total cavo-pulmonary connection for complex congenital heart disease]

Between April 1994 and January 1997, 10 patients with complex congenital heart disease were treated with total cavo-pulmonary connection(TCPC). They included 7 males and 3 females, aged 2-17 years(mean 10.1 years). These cases were single ventricle in 5, tricuspid atresia in 4, severe Ebstein anomaly in 1. For construction of the right atrial lateral tunnel, Gore-Tex patch was used in 9 cases and autologous right atrial wall in another, 4 of the 10 patients underwent TCPC without aortic crossclamping. There were no operative deaths. The follow-up is 2-36 months(mean 12.3 months). All of these patients did well and were in NYHA class I. The advantages, operative indication and technique of TCPC and the experience of improvement of surgical results are briefly discussed in this paper.

Molecular isolation and characterisation of carp transforming growth factor beta 1 from activated leucocytes

The transforming growth factor (TGF beta) family of proteins are a set of pleiotropic secreted signalling molecules with unique and potent immunoregulatory properties. In this study the molecular cloning of carp TGF beta 1 is reported. A partial cDNA of the TGF beta protein was initially identified from a cDNA pool, obtained by subtracting the cDNAs from Con A-induced carp head kidney leucocytes from uninduced carp head kidney leucocyte cDNA. The entire coding sequence was assembled by sequencing both ends of the cDNA clone by using an anchored PCR reaction. Sequence analysis revealed an ORF encoding a protein of 376 amino acids, containing the similar unique pattern of conserved cysteines (seven out of nine) in the cysteine knot structure which exists in all known TGF beta proteins. Compared with other animal TGF beta s, the cDNA clone shows approximately 59-42, 40-38 and 37-36% amino acid identity with TGF beta 1, TGF beta 3 and TGF beta 2 respectively. Carp TGF beta 1 is expressed at low levels in carp head kidney, spleen, egg and liver, whereas its messenger RNA level is increased after activation of the head kidney leucocytes with Con A. Sequence analysis and pattern of expression suggests that this is the carp TGF beta 1.

[Effect of emodin on development of hepatic fibrosis in rats]

OBJECTIVE

To investigate the effect of emodin on the development of hepatic fibrosis in rats.

METHODS

Forty percent of carbon tetrachloride (CCl4) dissolved in olive oil was injected subcutaneously to rats twice a week, for 6 weeks to produce hepatic fibrosis model, the rats of treated group were simultaneously injected with CCl4, treated with emodin in low, medium and high dose (20, 40 and 80 mg/kg body weight respectively) once a day for 42 days, which was dissolved in 0.5% sodium carboxymethylcellulose (CMC), while for rats of the control group, they only received CCl4 and CMC. Changes of serum hyaluronic acid, laminin and liver hydroxyproline were determined and histopathologic changes of liver was examined by optical microscopy and electronmicroscopy.

RESULTS

Compared with the model group, in the emodin treated group: (1) Serum hyaluronic acid and laminin were markedly reduced (P < 0.05 or 0.01); (2) liver hydroxyproline was significantly decreased (P < 0.05 or 0.01); (3) degree of fibrosis was reduced (P < 0.05 or 0.01); (4) hepatocyte injury was ameliorated.

CONCLUSION

Emodin has therapeutic effect on the development of hepatic fibrosis in rats. The effect might be related to slowing hepatocyte injury.