Detection of interleukin-8 in exudates from normal and inflamed human dental pulp tissues

OBJECTIVE

The purpose of this study was to investigate the level of IL-8 in exudates clinically obtained from normal and inflamed human dental pulp tissues so as to reveal the possible relationship between IL-8 and pulpitis.

METHODS

Samples of 2 microliters of pulpal exudate from each normal or clinically diagnosed as acute or chronic pulpitis teeth was obtained by filter paper strips and IL-8 level was measured by ELISA method.

RESULTS

No IL-8 was detected in the samples from normal pulp, but significant amount of IL-8 appeared in inflamed pulp tissues, and the level of IL-8 in exudates of acute stage of pulpitis was higher than that of chronic stage (P < 0.01).

CONCLUSIONS

This study demonstrates that IL-8 is produced and accumulated in pulp inflammation and may play a role in the occurrence and development of human pulpitis.

[Relationship between serum epidermal growth factor and uterine leiomyoma]

OBJECTIVE

To study the effects of epidermal growth factor (EGF) on uterine leiomyoma and the relationship of EGF and estrogen, progesterone.

METHODS

Fourty patients with uterine leiomyoma and twenty normal women were studied. Serum EGF level was determined by radioimumunoassay, estradiol (E2) and progesterone (P) levels were measured by enzyme marked monoclonal antibody assay.

RESULTS

Serum EGF, E2 and P levels in observed group were significantly higher than those in control group during secretive phase (P < 0.005). The serum EGF level in observed group during prolifrative phase was significantly higher than that of secretive phase (P < 0.05). The serum EGF level increased while uterus enlarged; EGF wasn't related to E2(r = 0.25, P > 0.05) and was related to P (r = 0.71, P < 0.005). The EGF level was the highest when E2 and P both increased.

CONCLUSION

EGF has the effect on growth of uterine leiomyoma. It is possible that EGF secretion can be stimulated by E2 and the effect of P is stronger than E2.

The internal chondrocyte-specific promoter of the chick type III collagen gene is activated by AP1 and is repressed in fibroblasts by a complex containing an LBP1-related protein

The chick type III collagen gene contains an internal promoter in intron 23 in addition to the promoter preceding exon 1. The internal promoter, which is used preferentially in cultured chondrocytes, directs production of an alternative transcript that cannot encode type III collagen. This promoter is used ineffic-iently in skin fibroblasts, which transcribe the gene from the upstream promoter. We show below that the internal promoter is regulated by an activation element containing a potential activator protein 1 (AP1) site and a repressor element containing a potential binding site for leader binding protein 1 (LBP1). Electro-phoretic mobility shift assays indicate that the activation and repressor elements are bound by AP1 and an LBP1-related protein, respectively. Replacement of the AP1 site resulted in substantially decreased promoter activity in both chondrocytes and fibroblasts, indicating that this site is required for promoter function, but the low level of promoter activity in fibro-blasts is not due to loss of functional AP1. In contrast, replacement of the LBP1-like site increased activity only in fibroblasts, suggesting that this site is responsible in part for repression of promoter activity in fibroblasts.

Depressed IL-12-mediated signal transduction in T cells from patients with Sézary syndrome is associated with the absence of IL-12 receptor beta 2 mRNA and highly reduced levels of STAT4

Sézary syndrome (SS) is the leukemic phase of cutaneous T cell lymphoma characterized by the proliferation of clonally derived CD4+ T cells that release cytokines of the Th2 T cell phenotype (IL-4, IL-5, IL-10), whereas Th1 T cell cytokines (IL-2, IFN-gamma) are markedly depressed as is expression of IL-12, a pivotal cytokine for Th1 cell differentiation. Normal Th1 cells express both the beta 1 and beta 2 chains of the IL-12 receptor (IL-12R) and tyrosine phosphorylate STAT4 in response to IL-12. Th2 T cells express only the IL-12R beta 1 and thus do not tyrosine phosphorylate STAT4 in response to IL-12. To determine whether SS cells are Th2-like at the level of IL-12 signal transduction, we analyzed RNA from seven patients for the presence of message for the IL-12R beta 1 and beta 2 genes using RNase protection assays and assessed whether IL-12 induced tyrosine-phosphorylation of STAT4 by immunoblotting. In PBL from six of seven SS patients tested, beta 2 message was expressed at low to undetectable levels and its expression could not be stimulated by either IFN-alpha or IFN- gamma, which stimulated beta 2 expression in control PBL. The absence of beta 2 expression is further supportive evidence for the Th2 lineage of SS cells. However, unlike normal Th2 cells, SS cells also showed severely reduced levels of STAT4, suggesting that they have a depressed response to any inducer of the STAT4 signal transduction pathway, including IFN-alpha. This is the first observation linking STAT4 gene expression with a human disease and suggests that dysregulation of STAT4 expression may be significant to the development and/or progression of SS.

cDNA cloning and sequencing of MH2 domain of Smad2 from human dental pulp cells

OBJECTIVE

The purpose of this study was to clone and sequence the cDNA of MH2 domain of Smad2 from human dental pulp cells.

METHODS

In this study, total RNA was isolated from primary cultured human dental pulp cells and reverse-transcribed into cDNA. The desired DNA product was obtained by nested PCR with 4 smad2 MH2 domain-specific primers. The segment was inserted into pBluescript II SK vector and the resulting plasmid was transformed into E. coli JM109. The double-strand cDNA of positive clone was sequenced by PE317-A automatic sequencing.

RESULTS

cDNA of MH2 domain of Smad2 was obtained from human dental pulp cells. The sequence was consistent with that cloned from a human kidney cDNA library. No mutation was found.

CONCLUSION

This study provides the first evidence of expression of smad2 in human dental pulp cells, and indicates that TGF-beta signaling may be mediated by Smad2 in human dental pulp cells. The cDNA cloned in pBluescript/S2MH2 could be used for further functional studies of Smad2 and MH2 domain in dental pulp cells.

Retinoids synergize with interleukin-2 to augment IFN-gamma and interleukin-12 production by human peripheral blood mononuclear cells

We have demonstrated previously that cells from both the skin and peripheral blood from patients with cutaneous T cell lymphoma (CTCL) have elevated levels of protein and mRNA for Th2 cytokines, interleukin-4 (IL-4) and IL-5, and depressed levels of Thl cytokines, IL-2 and interferon-gamma (IFN-gamma). Furthermore, IL-12 in vitro can restore IFN-gamma production by these patients' cells to near normal levels. Because retinoids exert therapeutic activity in CTCL and are potent modulators of growth and differentiation of hematopoietic cells, we investigated the role of retinoids in modulating Thl cytokine production. Peripheral blood mononuclear cells (PBMC) from normal donors and patients with CTCL were cultured with medium, IL-2, 13-cis-retinoic acid, all-trans-retinoic acid, acetretin or etretinate alone, or IL-2 plus the retinoids for 24 h, and levels of IFN-gamma were determined using ELISA. IL-2 or retinoids alone could induce low but significant levels of IFN-gamma. However, when IL-2 was cultured with each retinoid, a synergistic augmentation of IFN-gamma levels (4-fold to 90-fold) was observed except in the case of etretinate. All-trans-retinoic acid (ATRA) was the most potent IFN-y inducer. Similar studies performed using PBMC from CTCL patients indicated the IFN-gamma augmentation occurred but in a blunted manner. The IFN-y-inducing effect of ATRA and 13-cis-retinoic acid could be abrogated by addition of anti-IL-12 antibodies, suggesting that IL-12 plays a role in the synergistic upregulation of IFN-gamma. Using an IL-12 p40-specific radioimmunoassay (RIA), we confirmed the presence of IL-12 in IL-2 plus retinoid-treated culture supernatants. Purified monocytes cultured with IL-2 plus ATRA did not secrete IL-12. Only when monocytes were cocultured with lymphocytes was there an increase in IL-12 production, suggesting the involvement of a paracrine feedback loop requiring both monocytes and lymphocytes. These data suggest that retinoids can induce Th1 cytokines from normal and CTCL PBMC and that this induction may be mediated through IL-12 production.

[The relationship between expression of extracellular matrix and clinical pathology of primary lung carcinoma]

OBJECTIVE

To study the relationship between expression of laminin (LN), fibronectin (FN), collagen IV (Col. IV) and clinical pathology of primary lung cancer.

METHODS

LSAB method was used to detect the expression of LN, FN and Col. IV in 184 cases of lung carcinoma.

RESULTS

Expression of LN and Col. IV in well and moderately differentiated pulmonary squamous cell carcinoma were both higher than that in poorly differentiated cases (P < 0.01), and marked difference was found between lymph node positive and negative cases (P < 0.05). Obvious difference in the expression of LN and Col. IV was found between the patient groups with squamous cell carcinoma who died within 1/2 year and those surviving more than 5 years (P < 0.01), as was the difference in expression of FN (P < 0.05). Obvious difference in the expression of FN and Col. IV was found between patients groups with adenocarcinoma who died within 1/2 year and those surviving more than 5 years (P < 0.05, 0.01).

CONCLUSIONS

The expression of LN and Col. IV correlated with histological grading and lymph node metastasis of pulmonary squamous cell carcinoma; LN, FN, Col. IV can also be regarded as a parameter for evaluating prognosis of pulmonary squamous cell carcinoma. The expression of FN and Col. IV can be regarded as a parameter for evaluating the prognosis of pulmonary adenocarcinoma.

Adrenal sparing surgery for renal cell carcinoma

OBJECTIVE

To investigate the feasibility of adrenal sparing surgery for selected renal cell carcinoma (RCC), since the necessity of routine adrenalectomy during radical nephrectomy for RCC has been challenged in recent years.

METHODS

178 patients underwent perifascial nephrectomy in a 16-year period. Of these patients, 96 had ipsilateral adrenal gland preserved during nephrectomy and 82 underwent concomitant adrenalectomy. 75 excised adrenal specimens were examined pathologically. Disease specific survival rates were assessed according to the pathological stage of the tumors.

RESULTS

Of the 75 patients, 53 presented a macroscopically normal adrenal gland without pathohistological changes. The other 22 patients were suspected to have adrenal metastasis intraoperatively, while only 5 of them were confirmed to have adrenal involvement by histopathology. Two patients in the adrenal gland preservation group developed ipsilateral adrenal recurrence and synchronous or metachronous contralateral adrenal metastasis during follow-up, although both were documented to have a normal-appearing adrenal gland intraoperatively. Five patients with adrenal metastasis and 2 patients with adrenal recurrence had large renal tumors. The survival difference among subgroups of patients undergoing adrenalectomy or with adrenal gland left in situ was not statistically significant.

CONCLUSION

Adrenal sparing surgery could be done for patients with small renal tumors along with macroscopically normal ipsilateral adrenal glands.

Photoactivated hypericin is an anti-proliferative agent that induces a high rate of apoptotic death of normal, transformed, and malignant T lymphocytes: implications for the treatment of cutaneous lymphoproliferative and inflammatory disorders

Hypericin is a photodynamic compound activated by either visible (400-700 nm) or UVA (320-400 nm) light, and has been shown to inhibit the growth of a variety of neoplastic cell types. In this study, hypericin was found to inhibit proliferative responses of malignant T cells derived from the blood of patients with cutaneous T cell lymphoma. Control cells included peripheral blood mononuclear cells (PBMC) from normal volunteers or Epstein-Barr virus-transformed lymphocytes. Cells from each of these populations were incubated with serial dilutions of hypericin or 8-methoxypsoralen and then stimulated with the mitogen ConA (10 microg per ml). Cultures were prepared in the dark to minimize photoactivation of the hypericin. Proliferation was measured by [3H]thymidine labeling after 72 h. Hypericin, photoactivated with 1.1-3.3 J white light per cm2, inhibited cellular proliferation of malignant T cells with IC50 values from 0.34 to 0.53 microM, normal PBMC with IC50 values of 0.11-0.76 microM, and Epstein-Barr virus-transformed cells with IC50 values of 0.75-3.2 microM. UVA-photoactivated hypericin (0.5-2.0 J per cm2) could also inhibit proliferation with IC50 values of 0.57-1.8 microM, 0.7-4.6 microM, and 2.0-3.7 microM for malignant, normal, or Epstein-Barr virus-transformed cells, respectively. Hypericin, photoactivated with either UVA or white light, could induce near complete apoptosis (94%) in malignant cutaneous T cell lymphoma T cells, whereas lower levels of apoptosis (37-88%) were induced in normal PBMC. These data indicate that hypericin inhibits mitogen-induced proliferation of malignant T cells from patients with cutaneous T cell lymphoma, PBMC from normal individuals, as well as Epstein-Barr virus-transformed lymphocytes, and that inhibition of cell proliferation is dependent on the concentration of hypericin used and the dose of light required to photoactivate the compound. Induction of apoptosis is, in part, one mechanism by which photoactivated hypericin inhibits malignant T cell proliferation.

Use of biological response modifiers in the treatment of cutaneous T-cell lymphoma

Cutaneous T-cell lymphoma (CTCL) is typically a skin-infiltrating, clonal proliferative disorder of CD4+ T cells that exhibit a T-helper type 2 cytokine phenotype. Therapeutic decisions are based on the extent of disease and the observations that host-antitumor responses occur and that these responses may be blunted by the immunosuppressive cytokines produced by the malignant T cells. Biologic response modifiers, which may enhance cell-mediated immunity and antitumor responses, are active agents in the treatment of CTCL. The rationale and use of biologic response modifiers to treat CTCL are reviewed in this article.

Mineralized nodule formation by human dental papilla cells in culture

Human dental papilla cells were enzymatically separated from deciduous tooth germs of an 8-month-old embryo legally aborted. The second passage cells were cultured up to 35 days in 3 groups. The beta-GP group was cultured in the Dulbecco MEM containing ascorbic acid and beta-glycerophosphate supplemented with 15% fetal bovine serum. The Dex group was in the same medium, in addition containing dexamethasone. The control group contained none of the 3 chemicals. Mineralized nodules were formed after 15 days in the beta-GP and Dex groups. Only in the presence of ascorbic acid and organic phosphate did they mineralize. The addition of dexamethasone caused a significant increase in the number of nodules. By electron microscopy, the nodules contained needle-shaped crystals associated with a network of collagen fibrils. Calcium and phosphorus were detected by energy-dispersive X-ray microanalysis in the nodules. Furthermore, the crystalline material exhibited a pattern consistent with hydroxyapatite and dentin when examined by X-ray diffractometry. Cells showed high levels of alkaline phosphatase activity, which was increased 2-3 times in the presence of the 3 chemicals. These results indicated that human dental papilla cells have the ability to form dentin in culture. The formation of mineralized nodules by human dental papilla in vitro provides a useful model for studying the morphogenesis and differentiation of dental papilla ectomesenchyme.

The chick type III collagen gene contains two promoters that are preferentially expressed in different cell types and are separated by over 20 kb of DNA containing 23 exons

Type III collagen is present in prechondrogenic mesenchyme, but not in cartilages formed during endochondral ossification. However, cultured chick chondrocytes contain an unusual transcript of the type III collagen gene in which exons 1-23 are replaced with a previously undescribed exon, 23A; this alternative transcript does not encode type III collagen. This observation suggested that, although production of type III collagen mRNA is repressed in chondrocytes, transcription of the type III collagen gene may continue from an alternative promoter. To test this prediction, we isolated and characterized both the upstream and internal promoters of this gene and tested their ability to direct transcription in chondrocytes and skin fibroblasts. The upstream promoter is active in fibroblasts, but inactive in chondrocytes, indicating that repression of type III collagen synthesis during chondrogenesis is transcriptionally mediated. Additionally, sequences in intron 23, preceding exon 23A, function as a highly active promoter in chondrocytes; transcription from this promoter is repressed in fibroblasts. Thus transcriptional control of the type III collagen gene is highly complex, with two promoters separated by at least 20 kb of DNA that are preferentially expressed in different cell types and give rise to RNAs with different structures and functions.

Pathogenesis of cutaneous T-cell lymphoma: implications for the use of recombinant cytokines and photopheresis

Cutaneous T-cell lymphoma (CTCL) is a clonally derived, skin invasive malignancy of CD4+ cells with the phenotype of mature helper T cells. We previously demonstrated that the leukaemic form of CTCL (Sézary), is characterized by prominent immunological defects including depressed cell-mediated immunity. We also demonstrated increased production of T-helper type 2 (Th2) cytokines (IL-4, IL-5) and deficient Th1 cytokines (IL-2 and IFN-gamma) by their peripheral blood mononuclear cells (PBMC) and detected IL-4 and IL-5 mRNA within lesional skin of patients with all stages of CTCL. A marked defect in IL-12 production has also been noted, which may also play a role in depressed cell-mediated immunity. These results suggested that the malignant CD4+ cells were Th2 cells. Thus, the immune aberrations have been attributed to the cytokine abnormalities triggered by the malignant T-cell population. Because CTCL responds to biological response modification, we focused on strategies for reversing the cytokine and immune defects by in vitro testing of novel biological response modifiers. Our results indicate that IFN-alpha potently suppresses the abnormal IL-4 and IL-5 production, that IL-12 can correct the deficient IFN-gamma production and cell-mediated cytotoxicity, and that retinoids can enhance IFN-gamma and IL-12 production. We also studied the in vitro growth characteristics of the malignant CD4+ cells and determined that IL-12 and IFN-alpha significantly suppress growth of these cells. These studies led to a phase I trial of IL-12 to treat CTCL. Also, we have determined that photopheresis produces a high clinical response rate among Sézary syndrome patients. This therapy not only augments functions of monocytes but also induces the malignant T cells to undergo a high rate of apoptosis. We discuss how these therapies might be employed in concert to produce the optimum desired anti-tumour effect.

Calcitonin gene-related peptide inhibits proliferation and antigen presentation by human peripheral blood mononuclear cells: effects on B7, interleukin 10, and interleukin 12

CGRP is a neuropeptide that has previously been described to possess immunosuppressive activities. CGRP is released from peripheral nerves that, in the skin, are in close physical association with dendritic APC. We sought to investigate the mechanisms by which CGRP can inhibit immune responses by studying its effects on human peripheral blood mononuclear cells (PBMC). Using allogeneic monocytes as stimulator cells, CGRP could inhibit the proliferation of PBMC by 47% when CGRP was present for the duration of culture. Interestingly, when the stimulator monocytes were incubated with CGRP for 2 h prior to irradiation then washed, the observed inhibition increased to 85%, suggesting that CGRP was exerting a direct effect on the monocyte stimulator population. Finally, the recall response to tetanus toxoid (TT) by PBMC from individuals vaccinated with TT 14 d prior was inhibited by 25-50% in the presence of CGRP. Also, CGRP decreased the levels of B7.2 but not B7.1 on treated monocytes, and this inhibition could be abrogated by the addition of anti-IL-10 antibody, suggesting that the inhibition was mediated by an increase in IL-10 production. Moreover, increased IL-10 production was confirmed by ELISA. Both IL-12 p40 and IFN-gamma levels in CGRP-treated cultures were found to be decreased by approximately 30%. The decrease in IL-12 p40 levels could be reversed by addition of anti-IL-10. These data suggest that CGRP inhibits PBMC proliferation, in part, through the release of IL-10, which in turn can downregulate important co-stimulatory molecules and the cytokines IL-12 and IFN-gamma.

The potential therapeutic role of interleukin-12 in cutaneous T-cell lymphoma

Cutaneous T-cell lymphoma (CTCL) is a lymphoproliferative disorder characterized by skin invasion of clonally derived malignant CD4+ lymphocytes that phenotypically resemble mature T-helper (Th) cells. Sezary syndrome (SzS) represents an advanced form of CTCL associated with generalized erythroderma and involvement of the peripheral blood by the malignant cell population. We have previously demonstrated aberrant cytokine production by peripheral blood mononuclear cells (PBMCs) in SzS characterized by increased IL-4 and deficient IL-2 and IFN-gamma production, as well as increased expression of mRNA for IL-4 and IL-5 within active skin lesions, indicating that the clonal T-cell population is likely derived from the T-helper type 2 (Th2) subset of helper T lymphocytes. Furthermore, a variety of immune abnormalities have been observed in association with SzS that have been attributed to the cytokine abnormalities. Because IL-12 is a potent inducer of IFN-gamma production and causes the activation of cytotoxic lymphocytes, we assessed the production of IL-12 by PBMCs from SzS patients, and whether IL-12 could alter the unfavorable cytokine balance typical of SzS and, thus, possibly lead to correction of immune defects. In this review, we present our data, which indicate that patients with SzS exhibit marked defects in monocyte production of IL-12 p70. Moreover, in vitro culture of PBMC from SzS patients with recombinant IL-12 leads to reconstitution of normal IFN-gamma production and markedly enhances cell-mediated cytotoxicity.

The chick alpha2(I) collagen gene contains two functional promoters, and its expression in chondrocytes is regulated at both transcriptional and post-transcriptional levels

Embryonic chick cartilages contain transcripts derived from the alpha2(I) collagen gene, although type I collagen is not normally found in these tissues; most of these RNAs are alternative transcripts initiating within intron 2. Use of the internal start site results in replacement of exons 1 and 2 with a previously undescribed exon and a change in the translational reading frame; thus, the alternative transcript cannot encode alpha2(I) collagen. We have demonstrated that production of the alternative transcript is due to activation of an internal promoter in chondrocytes and have identified a 179-base pair domain that is required for its activity. Furthermore, we have shown that the alternative transcript resulting from activation of the internal promoter turns over relatively rapidly; thus, the steady-state level of this transcript is less than predicted based on the transcription rate. The upstream promoter is only partially repressed in chondrocytes, suggesting that the lack of authentic alpha2(I) collagen mRNA may also be due in part to decreased mRNA stability. Thus, repression of alpha2(I) collagen synthesis in cartilage involves both transcriptional and post-transcriptional mechanisms. In contrast, repression of alpha1(I) collagen synthesis appears to be mediated primarily at the level of transcription.

[The inhibitory effect of TNF-alpha on alkaline phosphatase activity of human periodontal ligament fibroblasts]

The present investigation was to identify the impact of recombinant human tumor necrosis factor-alpha (TNF-ALPHA) on alkaline phosphatase (ALP) activity of cultured human periodontal ligament fibroblasts (HPLF). It was found that, after treatment with TNF-alpha, HPLF in the experimental groups showed significantly lower ALP activity than in the blank control groups (P < 0.01). Further, the ALP activity was observed to decrease progressively with increasing TNF-alpha concentrations. These findings indicate that TNF-alpha possesses a remarkable concentration-dependent inhibitory effect on human periodontal ligament fibroblasts.

Alternative transcript of the chick alpha 2(I) collagen gene is transiently expressed during endochondral bone formation and during development of the central nervous system

Endochondral bone formation is characterized by several transitions in the pattern of collagen gene expression, the best characterized of which occurs during chondrogenesis. Prechondrogenic mesenchymal cells synthesize predominantly type I collagen; during chondrogenesis, type I collagen synthesis ceases and production of cartilage-characteristic collagens is initiated. We previously identified the molecular mechanism that mediates cessation of alpha 2(I) collagen synthesis in chondrocytes (Bennett and Adams [1990] J. Biol. Chem. 265:2223-2230). This mechanism involves a change in the transcription initiation site, resulting in an alternative transcript that cannot encode alpha 2(I) collagen. In this report we demonstrate that the alternative transcript appears only transiently in cartilage. Its initial appearance is coincident with the onset of high levels of type II collagen synthesis in differentiated chondrocytes. However, it disappears in hypertrophic cartilage, and production of the authentic alpha 2(I) collagen mRNA is reinitiated, contributing to synthesis of a high level of type I collagen in hypertrophic chondrocytes at the chondro-osseous junction. We also show that the alternative transcript is not restricted to cartilage during embryonic development, since it initially appears in presomite embryos, well before the appearance of cartilage. At early stages of embryo-genesis the alternative transcript is restricted to tissues derived from neuroectoderm; its appearance in those tissues is also transient. These data suggest that production of the alternative transcript of the alpha 2(I) collagen gene may be required for cessation of alpha 2(I) collagen synthesis during chondrogenesis, but the alternative transcript may be involved in other important developmental programs as well.

Erythropoietin-dependent inhibition of apoptosis is supported by carboxyl-truncated receptor forms and blocked by dominant-negative forms of Jak2

Apoptosis, or programmed cell death (PCD), recently has emerged as an important homeostatic mechanism within several hematopoietic lineages. This process is subject to both positive and negative modulation by cytokines and within the erythroid lineage is inhibited by interleukin-3, stem cell factor, and erythropoietin (Epo). Through the expression of carboxyl-truncated Epo receptor mutants in FDC-P1 cells, a receptor form possessing 80 membrane-proximal cytoplasmic residues is shown to efficiently mediate Epo-dependent inhibition of PCD. This is in contrast to previous studies that attributed this activity to a distal carboxyl-terminal receptor subdomain (and/or heterodimerization of wild type Epo receptors with a truncated non-functional receptor form). Epo-dependent inhibition of PCD also is shown to be blocked by ectopic expression of kinase-deficient dominant-negative forms of Jak2 (Jak2 delta VIII and Jak2-829), further underlining a role of this membrane-proximal subdomain of the Epo receptor in the inhibition of PCD. To our knowledge, this comprises the first direct evidence for an essential role for a Jak tyrosine kinase (Jak2) in this apoptotic response pathway.

Dominant negative effects of a carboxy-truncated Jak2 mutant on Epo-induced proliferation and Jak2 activation

Members of the Janus family of protein tyrosine kinases are emerging as primary, receptor-associated transducing factors among numerous cytokine systems. However, little is understood regarding mechanisms of recruitment of these kinases to receptor complexes and their ligand-dependent activation. To initially address these questions, we have assessed effects of ectopically expressing a carboxy-truncated form of Jak2 (Jak2-829) in Epo-responsive DAER cells. Expression of this truncation mutant at low levels efficiently inhibited both Epo-dependent activation of endogenous Jak2 and Epo-induced mitogenesis (10% to 39% of parental DAER cells). These results suggest that amino-terminal domains of Jak2 may mediate the assembly of Jak2/Epo receptor complexes and that integration of Jak2-829 into receptor complexes may effectively inhibit the activity of oligomeric Jak2/receptor assemblages.

[Preparation and application of ELISA kit for detection of G-CSF]

By adding monoclonal antibodies from BALB/c mice to the granulocyte colony-stimulating factor (G-CSF), we established a sandwich ELISA for detecting G-CSF levels in human serum samples. G-CSF was measured in 157 normal serum samples and in 153 serum samples from patients with no clinical manifestation of bacterial infection and in 269 serum samples from patients with clinical diagnosis of bacterial infection and in 31 serum samples from patients with positive bacterial infection according to cell culture. It was found that the positive rates of G-CSF were zero in normal serum samples, only 6.5% in patients with no clinical manifestation of bacterial infection, 89.2% in patients with clinical diagnosis of bacterial infection and 100% in patients with bacterial culture positive for infection. Our results reveal that the sandwich ELISA for detection of G-CSF levels in human serum samples may be useful for diagnosing patients with bacterial infection and for clinically guiding the rational use of antibiotics.

Inhibition of erythropoietin-induced mitogenesis by a kinase-deficient form of Jak2

Receptors for a variety of hematopoietins, interferons alpha/beta and gamma, and growth hormone have recently been shown to mediate rapid, ligand-dependent activation of the Janus-type cytosolic protein-tyrosine kinases Jak1, Jak2, and/or tyk-2. This finding extends relatedness among class I and II cytokine receptors to a functional context and provides an initially satisfying mechanistic analogy to protein-tyrosine kinase-encoding receptors of the epidermal growth factor/platelet-derived growth factor/insulin family. Through the construction and expression of a kinase-deficient form of Jak2 (JK2 delta VIII) in interleukin-3 (IL-3)/erythropoietin (Epo)-dependent DAER cells, we have tested whether activation of Jak2 is required for induced mitogenesis via these class I cytokine receptors. Ectopic expression of JK2 delta VIII inhibited Epo- and IL-3-induced activation of endogenous wild-type Jak2, transiently attenuated IL-3-dependent growth, and essentially abrogated Epo-induced proliferation in this model system. These dominant-negative effects provide the first direct experimental evidence for an essential role for Janus kinase activation in mitogenesis and suggest that distinct effectors may mediate IL-3-induced versus Epo-induced pathways.

An alternative transcript of the chick type III collagen gene that does not encode type III collagen

Type III collagen, a ubiquitous protein found in most connective tissues, is not present in hyaline cartilage. However, we have identified an alternative transcript of the type III collagen gene in cultured chondrocytes from several embryonic chick cartilages. This RNA contains exons 24-52, but exons 1-23 are replaced by 70 nucleotides of unique sequence, suggesting that transcription initiates at an alternative promoter. Two of the open reading frames in the alternative transcript are out of frame with the collagen coding sequence; a third open reading frame encodes the carboxyl-terminal two-thirds of the collagen sequence. Thus, this RNA cannot serve as a template for synthesis of normal type III collagen and may encode noncollagenous proteins and/or a truncated collagen. The alternative transcript has been detected as early as 2.5 days of embryogenesis and at later stages is present at low levels in many tissues, including limb mesenchyme and cartilage. These results, together with our previous identification of an alternative transcript of the chick alpha 2(I) collagen gene (Bennett, V. D., and Adams, S. L. (1990) J. Biol. Chem. 265, 2223-2230), suggest that some collagen genes may have alternative functions that are independent of their roles in collagen production.

Predictions of polarized multilayer theory of solute distribution confirmed from a study of the equilibrium distribution in frog muscle of twenty-one nonelectrolytes including five cryoprotectants

We determined the equilibrium distribution of twenty-one nonmetabolized nonelectrolytes in frog muscle cells. In all cases, plots of the equilibrium intracellular concentrations of a solute in the cell water against the external concentrations of the solute yielded straight lines in agreement with the prediction of such a rectilinear plot by the polarized multilayer (PM) theory. The slopes of these straight lines yield the equilibrium distribution coefficients or q-value of that solute. It was shown that, again in agreement with the PM theory, the q-values of fourteen nonelectrolytes vary with the molecular volumes of the nonelectrolytes, obeying the "size rule", i.e., the larger the solute, the lower its q-value. The q-values of the remaining seven nonelectrolytes also decrease with their molecular volumes but on a separate curve. These q-value vs. molecular volume plots (q-v plots) show strong resemblance to similar q-v plots of solutes in dialysis sacs containing proteins and polymers assuming the fully-extended conformation (extrovert models) but no, or only weak, resemblance to q-v plots of solutions containing native globular proteins (introvert models). These findings also support the PM theory, according to which some protein(s) pervasively present in cells are in the fully-extended conformation; and that these fully extended cell protein(s) polarize(s) in multilayers all or virtually all cell water. The relationship between the q-values of the nonelectrolytes and the solutes' respective molecular volume are described by two sets of theoretical curves, calculated from an equation introduced in the preceding paper. Both curves were computed on the basis of the same exclusion intensity (Uvp = 126 cal/mole). This factor measures the extra water-to-water interaction of the polarized water which acts to keep solute out of the cell water in degree according to the size of the solute. The two curves are computed on the basis of two different values of U(s), which represents the surface or solute component of the polarization energy, describing the affinity of the solute for the dynamic water structure: one curve which roughly predicts the q-value of fourteen of the nonelectrolytes studied was computed with a U(s) equal to 119 cal/mole. The second curve which roughly predicts the q-value of the remaining seven solutes was computed on the basis of a higher U(s) (156 cal/mole).(ABSTRACT TRUNCATED AT 400 WORDS)

[GC-MS analysis of essential oils in needles of Pinus in northeastern China]

The essential oils of five species of Pinus (P. densiflora, P. sylvestris var. mongolica, P. sylvestris var. sylvestriformis, P. tabulaeformis and P. takahasii) have been analysed by GC-MS. Fifty compounds have been identified.

Rapid induction of type X collagen gene expression in cultured chick vertebral chondrocytes

During endochondral ossification, small rapidly proliferating chondrocytes mature into flattened disc-shaped cells and then into large round hypertrophic cells. These morphological changes are accompanied by a decrease in the rate of cell proliferation. Type X collagen synthesis is initiated during chondrocyte maturation and reaches very high levels in the hypertrophic cells. We have analyzed type X collagen gene expression in chick embryo vertebral chondrocytes that were allowed to mature in monolayer culture and were then switched to suspension culture. The resuspended chondrocytes changed in shape from flat to round and decreased the proliferation rate as they do in vivo. These events were accompanied by a rapid, dramatic increase in type X collagen gene expression at the levels of transcription, steady-state mRNA and protein synthesis, as well as an increase in the number of cells producing type X collagen. The amount of type X collagen gene expression in resuspended chondrocytes was comparable to that in mineralizing cartilage in vivo. These results indicate that events accompanying the switch from monolayer to suspension culture (for example, the change from a flat to a round shape and/or the decrease in proliferation rate) may play a role in the induction of type X collagen gene expression during chondrocyte maturation. Thus we have developed an in vitro system that appears to mimic the events occurring during in vivo chondrocyte maturation. This in vitro model may provide an ideal system for further examination of the parameters regulating chondrocyte maturation and type X collagen gene expression.

[Analysis of essential oils in roots and fruits of Angelica in Northeast China]

The essential oils of roots and fruits of five species of Angelica have been examined and analysed by GC-MS-DS; 59 chemical compounds are reported, of which alpha-pinene, myrcene and p-cymene are common to all five species. This paper provides a scientific basis for developing the resources of this genus in the Northeast.

Plasma gamma-aminobutyric acid in experimental fulminant hepatic failure of rats and its diagnostic value in hepatic encephalopathy

The plasma concentration of gamma-aminobutyric acid (GABA) was measured by radioreceptor assay in galactosamine (GalN)-induced Wistar rat model of fulminant hepatic failure (FHF). The results of sequential observations in 10 FHF rats showed that the plasma GABA concentration doubled 24 hours after GalN injection, while there was no obvious clinical evidence of hepatic encephalopathy (HE). In overt HE 48 hours after the administration of GalN, the plasma concentration of GABA reached the peak value of 9,744 +/- 1,661 pmol/ml, which was 12 times as high as that before GalN injection. The consciousness, plasma concentration of GABA and SGPT activity became normal 120 hours after GalN injection. It is suggested that determination of plasma concentration of GABA is of value in the diagnosis of HE.

Studies of adsorbents for hemoperfusion in artificial liver support. I. Preparation and in vitro studies of cross-linked agarose beads entrapped activated charcoal (CAAC)

A new method for the preparation of the cross-linked agarose beads entrapped activated charcoal (CAAC) is reported. Since the agarose-encapsulated adsorbents reported elsewhere cannot stand high temperature for sterilization, the CAAC has the advantage of thermal stability to withstand autoclave at 121 degrees C. for 1/2 hour without breaking up or melting. A further advantage of CAAC is that the adsorbent has a much better consistency with good mechanical strength and elasticity, so that it can be formed into beads of a diameter less than 1 mm. This will not only give a better adsorption capacity than larger beads, but can also assure a better blood flow than soft beads which usually interfere in hemoperfusion due to compacting and sludging. Preliminary investigations indicate that the CAAC is relatively hemocompatible.