Regulation of apoptosis in mature alphabeta+CD4-CD8- antigen-specific suppressor T cell clones

The regulation of apoptosis in mature CD4+ or CD8+ alphabeta+ T cells has been well studied. How the survival and death is regulated in peripheral CD4-CD8- (double negative, DN) alphabeta+ T cells remains unknown. Recent studies suggest that peripheral DN T cells may play an important role in the regulation of the immune responses mediated by CD4+ or CD8+ T cells. Here, we used immunosuppressive DN T cell clones to elucidate the mechanisms involved in the regulation of death and survival of alphabeta+ DN T cells. The DN T cell clones were generated from the spleen cells of 2C transgenic mice, which express the transgenic TCR specific for Ld and permanently accepted Ld+ skin allografts after pretransplant infusion of Ld+ lymphocytes. We report that 1) the mature DN T cells are highly resistant to TCR cross-linking-induced apoptosis in the presence of exogenous IL-4; 2) Fas/Fas-ligand and TNF-alpha/TNFR pathways do not play an apparent role in regulating apoptosis in DN T cells; 3) the DN T cells constitutively express a high level of Bcl-xL, but not Bcl-2; 4) both Bcl-xL and Bcl-2 are up-regulated following TCR-cross-linking; and 5) IL-4 stimulation significantly up-regulates Bcl-xL and c-Jun expression and leads to mitogen-activated protein kinase phosphorylation in DN T cells, which may contribute to the resistance to apoptosis in these T cells. Taken together, these results provide us with an insight into how mature DN T cells resist activation-induced apoptosis to provide a long-term suppressor function in vivo.

[The relationship between chromatographic retention value and grey model parameters]

The relationship between development parameter a, grey action variable u in the grey model GM(1,1) and parameters A,B which express the relation of k' and phi, that is, 1nk' = A + B phi have been studied. The functions of these two kinds of parameters which are a = -B lambda and u = B lambda eA[(1 - e-B lambda)(-1) - 1] are given. Therefore, it can predict the position of peaks and the possibility of separating the components in different mixtures. It verifies the experimental data, and gives out a proper method to amend equations. The results show that the function is fit for not only the research of chromatographic parameters of explosives but also the prediction of A,B values of other compounds.

[Evaluation of tumor necrosis factor-alpha and interleukin-6 levels in serum and peritoneal fluid of patients with endometriosis]

OBJECTIVES

To evaluate the levels of tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) before and after conservative laparoscopic surgery in patients with endometriosis.

METHODS

The TNF-alpha and IL-6 levels in serum and peritoneal fluid of 20 endometriotic patients and 10 control patients were determined by radioimmunoassay.

RESULTS

Significant parallel relationship existed between the stage of endometriosis and the TNF-alpha and IL-6 levels in serum and peritoneal fluid in endometriosis patients (r values: serum: 0.80, 0.52; peritoneal fluid: 0.79, 0.49, P < 0.05). After clearance of endometriosis foci with laparoscopic conservative surgery, the TNF-alpha and IL-6 levels decreased significantly.

CONCLUSION

Measuring TNF-alpha and IL-6 level may have important value in postoperative follow-up, surveillance and evaluation of the effectiveness of surgery.

[Changes of the expression of integrin alpha6beta1 and the activity of focal adhesion kinase in the liver sinusoidal endothelial cell in experimental fibrotic rats]

OBJECTIVE

To investigate the expression of integrin alpha(6)beta(1) and the activity of focal adhesion kinase (FAK) in liver sinusoidal endothelial cells (SECs) from experimental fibrotic rats induced by CCl(4).

METHODS

By in situ collagenase perfusion and two-step Percoll gradient centrifugation, SECs were isolated and cultured from normal and CCl(4) -treated Wistar rats. The expression of integrin alpha(6)beta(1) was determined by cell-ELISA, and the activity of FAK was assessed by immunoprecipitation-tyrosine kinase assay.

RESULTS

The integrin alpha(6)beta(1) was almost absent in the normal SECs and was up-regulated during the fibrotic process; SECs from experimental fibrotic rats possessed higher expression level of integrin alpha(6)beta(1) than normal SECs (P<0.05). The FAK activity in SECs from experimental fibrotic rats increased significantly as compared with the normal controls (P<0.05).

CONCLUSIONS

The expression of integrin alpha(6)beta(1) on SECs and the increase of FAK in SECs may be important in the phenotype and function changes of SECs during hepatic fibrogenesis.

[A study of genetic heterogeneity in Pfeiffer syndrome]

OBJECTIVE

To understand the molecular pathology of Pfeiffer syndrome.

METHODS

DNA from peripheral blood was examined in 4 families with Pfeiffer syndrome by SSCP-sequence analyses and PCR-restriction enzyme digestion.

RESULTS

The authors found the mutations of FGFR2 gene in two families, an A to G transition in the 3' acceptor splice site of intron 8 in a family, and Asp321 Ala substitution in exon 9 in another family. In addition, the mutation in exon 5 of FGFR1 gene (Pro252Arg) was found in a family.

CONCLUSION

These findings reveal the genetic heterogeneity of Pfeiffer syndrome and can help one understand the molecular mechanism of the disease.

Mechanisms for ganciclovir resistance in gastrointestinal tumor cells transduced with a retroviral vector containing the herpes simplex virus thymidine kinase gene

Transfer of the herpes simplex thymidine kinase (HSV-TK) gene into tumor cells confers sensitivity to the cells to the viral drug ganciclovir (GCV). Although the efficacy of the HSV-TK/GCV approach is well studied, the mechanisms for the resistance of HSV-TK-transduced tumor cells to GCV are poorly understood. Here, we examined the mechanisms for GCV resistance in HSV-TK-transduced gastrointestinal (GI) cell lines. Our results show that GCV sensitivities vary in vitro and in vivo among the different HSV-TK-transduced GI tumor cell lines. GCV-resistant colonies were isolated from several different HSV-TK-transduced GI tumor cell lines after 14 days of GCV treatment. Characterization of GCV-resistant colonies demonstrated that the HSV-TK gene was either partially or completely deleted from the resistant HSV-TK-transduced cells. In the HT-29 RM and MIAPACA-2 RM cells, a 220-bp deletion of the gene was found, whereas in the HT-29 R1-R5-resistant cells, the whole TK gene was found to be absent. Immunocytochemical studies using a polyclonal antibody to the TK protein demonstrated that the HSV-TK protein was absent in the GCV-resistant, HSV-TK-transduced cells. Transfection of the resistant cells with an adenoviral vector containing a HSV-TK gene restored sensitivity to GCV. The presence of GCV-resistant cells was only demonstrable in GI tumor cell lines that also demonstrated a poor bystander effect. Our results suggest that GCV resistance found in tumor cells transduced with a retroviral HSV-TK gene is due to the lack of a functional TK protein in the tumor cells rather than any intrinsic resistance of the cells to GCV. In tumor cells with a good bystander effect, the small percentage of TK-transduced cells that do not express the TK protein are probably killed by the bystander effect because GCV-resistant tumor cells were not found in these cell lines. GCV-resistant tumor cells were found only in tumor cell lines with a poor bystander effect, by which, presumably, the transduced tumor cells lacking a functional TK gene were not killed by the bystander killing effect.

A new technique of coronary artery ligation: experimental myocardial infarction in rats in vivo with reduced mortality

In vivo models of myocardial infarction following coronary artery ligation in the rat still suffer from high early mortality and a low rate of success of myocardial infarction. This study investigated the possibility of reducing early mortality and increasing the rate of myocardial infarction by modifications of surgical techniques. Eighteen rats were divided into two groups: normal control (3 rats) and ligation (15 rats). The major modifications of surgical techniques used in this study include: (1) no exteriorization of the heart, (2) ligation of the origins of the branches rather than the main trunk of the left coronary artery, (3) removal of air from the chest after closure, (4) supplying oxygen immediately after extubation. Following surgery, the rats recovered uneventfully and 11 rats were alive after 16 weeks. One rat, with a large myocardial infarction, died 2 h after surgery. Early mortality (during surgery and 1 week after surgery) was 6.7% with a success rate of myocardial infarction of 85%. The left ventricle in the ligation group showed significant dilation relative to normal and sham-operated control hearts (317% of control hearts, p < 0.001). However, myocardial mass did not increase. The average infarct size was 33%. These results demonstrate that a reduction in early mortality and an increased success rate of myocardial infarction can be achieved by modifications of surgical techniques.

A study of Helicobacterium pylori and prevention and treatment of chronic atrophic gastritis

The rate of detection of helicobacterium pylori (HP) in chronic atrophic gastritis (CAG) is 67%, HP being a slightly aerobic Gram-negative bacterium. Some drugs of traditional Chinese medicine (TCM) for clearing away heat and for removing blood stasis have significant effect on inhibition of HP. The drugs in both the recipe for nourishing yin, clearing away heat and invigorating blood circulation and the recipe for clearing away heat and invigorating blood circulation have inhibitory action on HP in vitro. All patients with CAG have symptoms of damp-heat and blood stasis. Radix et Rhizoma Rhei and Rhizoma Coptidis Decoction for Purging Stomach-Fire ([symbol: see text]) as the basic recipe and "Huo Wei" ([symbol: see text]) No. 2 recipe as the supplementary have good inhibitory effect on HP in inhibition tests. The results show several forms of the medicine all resulted in significant good therapeutic effect.

GABAergic inhibition in nucleus magnocellularis: implications for phase locking in the avian auditory brainstem

In the avian auditory brainstem, nucleus magnocellularis (NM) functions to relay phase-locked signals to nucleus laminaris for binaural coincidence detection. Although many studies have revealed that NM neurons exhibit intrinsic physiological and anatomical specializations for this purpose, the role of inhibition has not been fully explored. The present study characterizes the organization of GABAergic feedback to NM. Anterograde and retrograde labeling methods showed that NM receives a prominent projection from the ipsilateral superior olivary nucleus (SON). The functional features of this projection were explored in a brain slice preparation. Stimulating fibers from the SON evoked long-lasting, depolarizing responses in NM neurons that were blockable by bicuculline, a GABA(A) receptor antagonist. The slow time course of these responses allowed them to undergo temporal summation during repetitive stimulation. The summed GABAergic response was capable of blocking spikes generated in NM neurons by suprathreshold current injection. This inhibitory effect was attributable to a large reduction in input resistance caused by a combination of the opening of a GABAergic Cl(-) conductance and the recruitment of a low-voltage activated K(+) conductance. This large reduction of input resistance increased the amount of current necessary to drive NM neurons to threshold. The results lead us to propose that GABAergic inhibition enhances phase-locking fidelity of NM neurons, which is essential to binaural coincidence detection in nucleus laminaris.

[Relationships of angiotensinogen gene M235T variant with diabetic nephropathy in Chinese type 2 diabetes mellitus]

OBJECTIVE

To investigate whether angiotensinogen(AGT) gene M235T variant is associated with type 2 diabetes mellitus without nephropathy (DM) and/or diabetic nephropathy (DN) in Chinese type 2 diabetes.

METHODS

AGT genotypes of 84 cases with DM, 96 with DN and 98 controls were determined by polymerase chain reaction (PCR) amplification and restriction fragment length polymorphism analysis of the region of the variant.

RESULTS

Increased frequencies of T allele (0.82) and TT genotype (0.70) were observed in 96 subjects with DN, compared with those observed in 98 control subjects (0.63 and 0. 43 respectively, P = 0.003, P = 0.0004). The odds ratio associated with TT genotype was 3.47 (95% CI 1.51-7.94, P = 0.0033) for DN in analysis adjusted for several DN risk factors. There was no difference in allele distribution between 84 DM patients and the controls.

CONCLUSION

TT genotype of the AGT gene might be an independent risk factor of diabetic nephropathy in Chinese patients with type 2 diabetes mellitus.

[Changes of thyroid and adrenocortical functions after bone marrow transplantation with MAC conditioning regimen in leukemia patients]

OBJECTIVE

To investigate the effect of MAC conditioning regimen on endocrine glands function in leukemia patients after bone marrow transplantation(BMT).

METHODS

Thyroid and adrenocortical functions were assayed by radioimmunoassay (RIA) in 26 leukemia patients before and after BMT.

RESULTS

All patients had normal thyroid and adrenocortical functions before BMT. As compared with that pre BMT, the median serum TSH levels were increased at 1, 3 and 6 months post BMT(P < 0.01). This thyroid dysfunctions were found in 7 of 26 patients, 6 of whom were recovered at 6 months post BMT.

CONCLUSION

There was little effect of MAC conditioning regimen on adrenocortical function. Thyroid dysfunctions were found in 28% of the patients after BMT, and normalized in a short period without replacement therapy.

Immobilized IDA-type Cu2+-chelating membrane affinity chromatography for purification of bovine liver catalase

Cu2+-chelating membrane medium based on iminodiacetate-substituted modified short cotton cellulose was examined to purify bovine liver catalase (BLC) by affinity chromatography. The buffer pH notably affect BLC binding to the Cu2+-chelating membrane adsorbent. The results showed that under the chromatographic conditions chosen, 67.7% recovery of BLC attained with an overall 4.7-fold increase in specific activity in a single step. After purification of BLC, the chelating membrane adsorbent can easily be regenerated by imidazole or EDTA buffer. Different results were obtained by the two regeneration methods: the later is more effective than the former in reviving the purification characters of the chelating membrane adsorbent.

[Expression of P21 and P185 in benign and malignant epithelia of cheek mucosa]

To analyze the expression of P21 and P185 in normal epithelia, chronic non-specific inflammatory epithelia, squamous cell carcinoma and epithelia immediately adjacent to carcinoma of cheek mucosa, immunohistochemistry technique and image analysis technique were used. The results showed: there was excellently higher expression of P21 and P185 in squamous cell carcinoma and epithelia immediately adjacent to carcinoma than in normal and inflammatory epithelia of cheek mucosa, which were compactly correlative.

[Studies on microbial factor on color change of Dunhuang mural. III. Effect of Cladosporium sp. on color-change of red lead in the surface of mural]

The conditions isolated Cladosporium sp. from Mural of Dunhuang grottoe germinated on the surface of imitated mural were as follows: 20 degrees C RH 60% or 30 degrees C RH 50%, which could be reached occasionally in some grottoes. Bone glue had protective function on red lead, while Cladosporium sp. could decompose bone glue and form some metabolite (such as oxalic acid, etc) as it grows. Then it could form a special chemical circumstance, which promoted the change from red lead to while lead.