RESUMEN

Arabino-mycolates are components of the cell-wall skeleton of Mycobacterium bovis BCG (BCG-CWS). It is known that synthesized arabinomycolates induce the production of tumor necrosis factor alpha (TNF-α) in murine macrophage cell lines at an intensity similar to that of BCG-CWS. However the immunological activity of natural arabino-mycolates isolated from BCG has not been investigated, probably due to the complexity of the molecule. In this paper, we investigated the immunostimulatory activity of arabino-mycolates isolated from BCG-CWS by acid hydrolysis. Arabino-mycolates obtained by acid hydrolysis from the originally prepared CWS (SMP-105) of M. bovis BCG Tokyo 172 strain consisted mainly of mono-arabinose mono-mycolate, penta-arabinose tetra-mycolate and hexa-arabinose tetramycolate fractions. Arabino-mycolates significantly induced TNF-α production with an intensity comparable to that of CWS and enhanced delayed type hypersensitivity (DTH) reactions against inactivated tumor cells. Arabino-mycolates-induced TNF-α production was completely dependent on TLR2 and MyD88 pathways. These findings indicate that isolated natural arabino-mycolates possess potent adjuvant immunostimulatory activity.

Asunto(s)

RESUMEN

To investigate whether bound thrombin can induce modulation of SMemb expression in vascular smooth muscle (VSM) cells, messenger RNA (mRNA) expression was measured by in situ hybridization (ISH) and reverse transcription-polymerase chain reaction (RT-PCR) in cultured rabbit aortic VSM cells. To test the concentration- and time-dependent effect of bound thrombin on the expression of SMemb, confluent VSM cells were incubated for 48 h in 10% FBS-DMEM containing 0, 3, 10 and 30 units/ml of bound thrombin. In addition, the confluent VSM cells were incubated for 6, 12, 24 and 48 h in 10% FBS-DMEM containing 10 units/ml of bound thrombin. Consequently, bound thrombin significantly increased SMemb mRNA in a concentration- and time-dependent manner. When compared with the effect of rabbit fibrinogen (10 microg/ml) and native thrombin (10 units/ml), SMemb mRNA was significantly increased by bound thrombin and was slightly increased by native thrombin, but not by fibrinogen. Other myosin heavy chain (MHC) isoform (SM1 and SM2) mRNA expressions were not changed by fibrinogen, native thrombin or bound thrombin. ISH revealed that there was no significant difference in the expression of MHC mRNAs among fibrinogen, native thrombin or bound thrombin. Western blot analysis demonstrated that the SMemb protein level was significantly increased by 2.5-fold by bound thrombin. When the clot-forming activities in cultured medium containing native thrombin or bound thrombin were measured from 0.5 to 48 h, the activity of bound thrombin declined more slowly than that of native thrombin. In conclusion, bound thrombin could upregulate the expression of SMemb mRNA and protein in cultured VSM cells and the activity of bound thrombin was maintained for longer than that of native thrombin in culture medium.

Asunto(s)

RESUMEN

Telomeres of a specific length are essential for continuous cell proliferation. The length of telomeres must be maintained by telomerase action and the telomeric DNA-repeat binding protein must be protected. Therefore, there seems to be a relationship between cell immortality due to telomerase activity and telomeric DNA-repeat binding protein. We examined telomerase activity and the expression of telomeric-repeat binding factor 1 and 2 (TRF1 and TRF2) in gastric cancer. Telomerase activity was semi-quantified using the f-TRAP technique in 53 cancerous and non-cancerous gastric tissue specimens. TRF1 and TRF2 were also studied using an immunohistochemical method to determine the frequency of these factors in cell nuclei. Telomerase activity was observed in 79.2% of the cancerous tissue and in 39.6% of the non-cancerous tissue. The average semi-quantitative values for telomerase activity were 67.3 total product generated (TPG) unit/microg protein in cancerous tissue and 6.0 TPG unit/microg protein in non-cancerous tissue. Moreover, T0/1 tumor had the same incidence of telomerase activity as T2 or deeper tumors. These results indicated that the activation of telomerase begins at an early stage of carcinogenesis. TRF1 and TRF2 were detected in 45.1% and 42.9% of the cancerous tissue and in 70.6% and 65.6% of the non-cancerous tissue, respectively. In addition, low positive staining ratios were found for TRF1 and TRF2 when cancer had more deeply invaded. However, telomerase activity did not correlate with either TRF1 or TRF2. These findings suggest that optimal conditions for efficient telomerase are produced as cancer progresses, via suppression of TRFs.

Asunto(s)

RESUMEN

It has been reported that thrombin is liberated from fibrin clots by the action of fibrinolytic enzymes. It has also been reported that the liberated thrombin complexes with fibrin fragment E or (DD)E, which are denoted as bound thrombin. However, bound thrombin has not been isolated from clot lysate, and the structural characteristics of isolated bound thrombin have not been specified. In this study, we attempted to isolate the bound thrombin from clot lysate and to clarify its structural features. Rabbit fibrinogen was clotted with bovine thrombin, and clot lysate was prepared with urokinase. The bound thrombin was isolated from clot lysate by serial chromatography using a Sepharose 4B column immobilizing an anti-bovine thrombin antibody and a Sepharose 4B column immobilizing an anti-rabbit fibrinogen antibody. SDS-PAGE under unreduced conditions demonstrated that there were two different protein bands in the isolated bound thrombin. On a C4 reverse-phase HPLC, the bound thrombin from clot lysate was resolved by 4 M urea into alpha-thrombin and a fibrin fragment, the N-terminal regions of which were identified as alpha-, beta- and gamma-chains. Thus, in the bound thrombin, thrombin molecule would bind to rabbit fibrin fragment consisting of N-terminal central domain.

Asunto(s)

RESUMEN

BACKGROUND: Although the levels of immunoglobulin E (IgE) in the circulating blood are often elevated in patients with allergic diseases, such levels cannot always be considered as pathognomonic signs of allergy. The induction of allergic reactions in the tissue was inferred to be related to the amount of IgE passing through the vascular wall. AIMS: We attempted to clarify which compartment, the intravascular or extravascular, plays an important role in the regulation of the turnover of rat IgE. METHODS: The level of DNP-specific rat IgE in the serum was estimated by IgE-capture enzyme-linked immunosorbent assay, and the turnover of IgE was analyzed from its pharmacokinetic parameters. RESULTS: The transfer rate constants from the central to tissue compartment (Kct) were larger than those from the tissue to central compartment (Ktc) irrespective of the sensitized state. The value of the distribution volume of the tissue compartment (Vt) was larger than that of the distribution volume of the central compartment (Vc) irrespective of the sensitized state. CONCLUSIONS: These Findings suggest that the short half-life of rat IgE in the circulation could be attributable to the distribution of IgE from the intravascular to the extravascular compartment.

Asunto(s)

RESUMEN

OBJECTIVE: The present study was aimed to determine whether p16/MTS1, nm23-H1, E-cadherin, and CD44 proteins were expressed in nasopharyngeal carcinoma (NPC) and whether those expressions were pathologically significant in the progress of NPC. METHOD: We examined non-cancerous nasopharyngeal mucosa (20 cases) and NPC (80 cases) using immunohistochemistry with six different types of monoclonal antibodies against p16, nm23-H1, E-cadherin, CD44H, CD44v3, and CD44v6 proteins. RESULTS: The results showed that 1) the rates of positive p16 protein expression and of preserved E-cadherin protein expression in NPC were significantly lower than those in non-cancerous tissue (P <.01); 2) no significant difference in the rate of positive expression of nm23-H1, CD44H, CD44v3, and CD44v6 proteins were observed between non-cancerous nasopharyngeal mucosa and NPC; 3) no significant difference in the expression of those proteins were found by respective correlation analyses of sex, stage, and size of primary tumor in NPC; and 4) no significant difference in the rates of positive expression of CD44H, CD44v3, and CD44v6 proteins were observed in NPC between with and without lymph node metastasis, indicating that those gene products did not correlate with lymph node metastasis in NPC. However, there were inverse correlations between the expression of p16, nm23-H1, or E-cadherin protein and lymph node metastasis (P <.05), indicating that the expression of p16, nm23-H1, and E-cadherin gene were related to the carcinogenesis and tumor progression of NPC. CONCLUSION: Detecting the expressions of those gene products may provide clinically valuable information for therapeutic strategy and for predicting the prognosis of patients with NPC.

Asunto(s)

RESUMEN

It is known that Saiko-Keishi-To (TJ-10), a Kampo herbal medicine used for the treatment of epilepsy, shows a satisfactory curative effect even in the patients suffering from trigeminal neuralgia. To verify the effectiveness of TJ-10, Wistar rats with chronic neuralgia of the mandibular nerve were prepared and TJ-10 was administered to them for 4 weeks following the manifestation of pain in the mandibular region. The result reveals that the rise in the pain threshold in the mandibular region is more significant in the rats administered TJ-10 than in those in the control group. However, in the tail flick test, no significant change was observed in the pain threshold. These findings suggest that TJ-10 is effective for controlling the manifestation of pain in ligatured nerves, by local effect, not by general analgesic effect.

Asunto(s)

RESUMEN

The significant contribution of folded conformation (2) of the anxiolytic tandospirone (1) in aqueous solution was verified by dynamic 1H NMR. A structurally rigid mimic of 2 was designed and synthesized to evaluate the implication of 2 towards neuroleptic receptor binding. The designed structures provided a new rigid scaffold for dopamine D4 ligands.

Asunto(s)

RESUMEN

BACKGROUND: Cytologic findings of toxoplasmic lymphadenitis (TL) have been only sporadically reported. Intramammary lymph node is an extremely rare site for TL. CASE: A 47-year-old, healthy, female presented with a breast tumor, which was aspirated. The cytomorphologic features were interpreted as suggestive of TL. Histopathology of the excisional biopsy specimen and subsequent serologic examination confirmed the diagnosis. CONCLUSION: We obtained several characteristic findings in aspiration of TL. Of these, epithelioid cell clusters and monocytoid cells were the most diagnostic.

Asunto(s)

RESUMEN

Tyrosine protein kinase (Tyr-PK) regulation of L-type Ca2+ channel (CaL) current was studied in COS-7 cells expressing vascular smooth muscle-type alpha1C-b with no auxiliary subunit by using a whole-cell voltage clamp. The averaged peak amplitude of CaL currents was -0.33 +/- 0.03 at holding potential of -60 mV. Na(3)VO(4), genistein and phosphorylated p60(c-src) peptide had no effect on the current. Thus the alpha1C-b subunit may not be involved in Tyr-PK regulation of CaL current.

Asunto(s)

RESUMEN

Spontaneous orthotopic liver transplant (OLT) tolerance occurs uniformly between the inbred rat strains of DA (MHC haplotype RT1(a)) into PVG (RT1(c)) despite a fully allogeneic barrier. Animals transplanted in this combination do, however, undergo a rejection episode which appears to be self-limiting. In order to clarify this further we under took in situ measurements of the cytokines IL-2, IFN-gamma and TNF-alpha prior to, during and post rejection episode. The cytokine protein product was examined via immunoblotting assays and mRNA levels by RT-PCR. Comparisons were also made for syngeneic transplant combinations over the same time period. Peak protein expression of IL-2 and, to a lesser extent, IFN-gamma, occurred during the rejection episode between days 10 and 14. IFN-gamma was still present in syngeneic OLT on day 10 but was only present in allogeneic OLT on day 14. IL-2 was only detectable in allogeneic OLT on days 10 and 14. Transient increases in TNF-alpha occurred in allogeneic and syngeneic OLT with TNF-alpha levels falling by the peak rejection episode. Immunoblotting also confirmed the ability of hepatocytes to produce each of the cytokines studied. mRNA levels, by contrast, were maximal at days 1 and 10 for IL-2 and day 3 for IFN-gamma in allogeneic OLT when compared with syngeneic and non-transplanted controls. Earlier increases in IL-2 and IFN-gamma mRNA and time of peak protein expression do not correlate in this model. We therefore conclude that the measurement of peak mRNA levels alone are not enough to evaluate the rejection process especially since it is the cytokine protein products which have potential biological activity.

Asunto(s)

RESUMEN

FE-3 cells were established by Hanashiro et al. by hybridizing mouse myeloma cells (Sp2/0-Ag14/SF) with rat spleen cells that were freshly isolated from Brown-Norway rats sensitized with DNP-As. FE-3 cells can constitutively secrete IgE without stimulation by cytokines. Our preliminary experiments demonstrated that the IgE secretion was decreased at 3 days after start of culture and the addition of exogenous IgE into culture media depressed the secretion of IgE. Thus, we hypothesized that the IgE production in FE-3 cells may be regulated by a signal transduction through the binding of IgE to its high affinity receptor (Fc(epsilon)RI) or to an IgE binding protein on the cell surface. In this study, we aimed to identify the nucleotide sequence of IgE FE-3 and compared with those of mouse IgE and IgE IR162 to find a structural heterogeneity in the Fc region of IgE FE-3. We also tested if the mRNA of Fc(epsilon)RI was expressed in FE-3 cells using the reverse transcriptase-polymerase chain reaction (RT-PCR) method with the combination of sequencing analysis. Consequently, the cDNA sequence of IgE FE-3 was identical to that of the CH3 and CH4 domains in the epsilon-chain of rat IgE IR162, whereas the cDNA of Fc(epsilon)RI was identical to that of mouse, suggesting that the genes of IgE FE-3 and Fc(epsilon)RI was derived from that of rat spleen cells and mouse myeloma cells, respectively.

Asunto(s)

RESUMEN

OBJECTIVE: The present study was aimed at clarifying whether the microvessel density (MVD) and the expression of vascular endothelial growth factor (VEGF) were related to the degree of local invasion and metastasis in nasopharyngeal carcinoma (NPC). STUDY DESIGN: We measured the MVD and examined whether VEGF was expressed in NPC tissue using histological study combined with immunohistochemistry. METHODS: MVD and VEGF expression was measured in 73 specimens of NPC, 15 benign tumors of nasopharyngeal region, and 20 nasopharyngeal tissue without tumor. MVD and VEGF expression in NPC was compared between a metastasis group (49 specimens) and a non-metastasis group (24 specimens). RESULTS: Both MVD and VEGF expression were markedly increased in NPC tissue as compared with those in benign tumors of nasopharyngeal region. Both MVD and VEGF expression in NPC tissue with metastasis were statistically significantly increased as compared with those in NPC without metastasis. Therefore, the invasion and metastasis of NPC cells were closely related to MVD and the expression of VEGF in NPC tissue. CONCLUSION: The metastatic potency of NPC tissue and the prognosis of the patients with NPC can be estimated by measuring MVD and the expression of VEGF in NPC tissue. Drugs that have inhibitory actions on angiogenesis could be useful to prevent metastasis of NPC cells in the patients.

Asunto(s)

RESUMEN

To date, three carbapenem antibiotics have been introduced for clinical use, and they can be structurally classified into two types. One is a natural type that has the naturally-occurring carbapenem skeleton and a strongly basic (cationic) moiety in the C-2 side chain, like imipenem or panipenem. The other is a new generation carbapenem, meropenem, which has the 1 beta-methyl carbapenem skeleton and a less basic group in the C-2 side chain. It was reported that there were some significant differences among these two types of carbapenems concerning the antimicrobial profile, especially the antipseudomonal activity. Since Pseudomonas aeruginosa was one of the target pathogens of carbapenem antibiotics, these facts prompted us to overview the different mode of action among imipenem, panipenem and meropenem and clarify the structure-activity relationships of carbapenems with regard to the antipseudomonal activities. In this article, we discuss that both the chemical structure and the physicochemical properties of carbapenems greatly influence a variety of antipsedomonal actions including MIC, affinity for PBPs, outer membrane permeability, interaction with various beta-lactamases and multidrug efflux systems etc., and that the cationic center in the C-2 side chain plays an important role in antipseudomonal activities. This review will be helpful in developing new types of antipseudomonal carbapenems and/or new clinical applications of carbapenem antibiotics for treating pseudomonal infection.

Asunto(s)

RESUMEN

To investigate the possible regulation of large-conductance Ca2+-activated K+ channels (BKCa) by tyrosine phosphatases (Tyr-PPs), single-channel currents of myocytes from rat mesenteric artery were recorded in open cell-attached patches. Two structurally different Tyr-PP inhibitors, sodium orthovanadate (Na3VO4) and dephostatin, were used. The channels (236 pS) evoked at +40 mV and pCa 6, were significantly inhibited by 1 mM Na3VO4 (-81+/-3%, n = 10; P < 0.005). Similarly, 100 microM dephostatin strongly inhibited the BKCa channels (-80+/-7%, n = 7 ; P < 0.05). Therefore, BKCa channels in vascular smooth muscle cells may be regulated by tyrosine phosphatase-dependent signal transduction pathways, whose inhibition could attenuate the channel activity.

Asunto(s)

RESUMEN

To clarify interactions between the cytoskeleton and activity of L-type Ca(2+) (Ca(L)) channels in vascular smooth muscle (VSM) cells, we investigated the effect of disruption of actin filaments and microtubules on the L-type Ca(2+) current [I(Ba(L))] of cultured VSM cells (A7r5 cell line) using whole cell voltage clamp. The cells were exposed to each disrupter for 1 h and then examined electrophysiologically and morphologically. Results of immunostaining using anti-alpha-actin and anti-alpha-tubulin antibodies showed that colchicine disrupted both actin filaments and microtubules, cytochalasin D disrupted only actin filaments, and nocodazole disrupted only microtubules. I(Ba(L)) was greatly reduced in cells that were exposed to colchicine or cytochalasin D but not to nocodazole. Colchicine even inhibited I(Ba(L)) by about 40% when the actin filaments were stabilized by phalloidin or when the cells were treated with phalloidin plus taxol to stabilize both cytoskeletal components. These results suggest that colchicine must also cause some inhibition of I(Ba(L)) due to another unknown mechanism, e.g., a direct block of Ca(L) channels. In summary, actin filament disruption of VSM cells inhibits Ca(L) channel activity, whereas disrupting the microtubules does not.

Asunto(s)

RESUMEN

It has been reported that surgical procedures and postoperative pain suppress immune activities of the patient. But it is not clear if chronic pain in a small area affects immune activities. We prepared rats with chronic neuralgia of the mental branch originating from the mandibular nerve (a division of the trigeminal nerve) and examined the change of splenic NK-cell activity. Surgical procedures to prepare rat models for the study were as follows: one mental nerve was exposed and ligated at the mental foramen in order to create hypersensitivity in the ipsilateral innervated area. Splenic NK-cell activity 3 weeks after the surgery was reduced significantly in the operation group than that of the sham-operation group and the non-operated control group. The result suggests that the immune functions are remarkably affected by chronic pain evoked in a limited area such as the area innervated by the mental nerve.

Asunto(s)

RESUMEN

Habutobin, a thrombin-like enzyme from Trimeresurus flavoviridis venom, cleaves only the Arg(16)-Gly(17) bond in the rabbit Aalpha chain and releases fibrinopeptide A (FPA). To investigate the role of amino acid residues in the rabbit FPA sequence upon habutobin action, we examined the inhibitory effects of FPA and peptides containing partial sequences of FPA on the habutobin action. Fibrinopeptides from rabbit, human, bovine and dog were isolated and rabbit FPA was fragmented using dilute HCl. Rabbit FPA inhibited the action of habutobin although FPA from human, bovine and dog did not. Among the fragments of rabbit FPA, a heptapeptide Aalpha 3-9, the N-terminal region of rabbit FPA, competitively inhibited the release of FPA by habutobin, whereas the C-terminal hexapeptide of FPA (Aalpha 11-16) exerted no effect on the habutobin action. Synthetic tripeptides Ser-Thr-Phe corresponding to Aalpha 6-8 and Ala-Thr-Phe also inhibited the habutobin action, but Ser-Asp-Phe and Ala-Thr-Gly did not. It is concluded that habutobin would recognize the region around Thr(7)-Phe(8) in the sequence of rabbit FPA (Aalpha 1-16) prior to the cleavage of the Arg(16)-Gly(17) bond.

Asunto(s)

Asunto(s)