Exosome Isolation Using Chitosan Oligosaccharide Lactate-1-Pyrenecarboxylic Acid-Based Self-Assembled Magnetic Nanoclusters

Exosomes are small extracellular vesicles that play a crucial role in intercellular communication and offer significant potential for a wide range of biomedical applications. However, conventional methods for exosome isolation have limitations in terms of purity, scalability, and preservation of exosome structural integrity. To address these challenges, an exosome isolation platform using chitosan oligosaccharide lactate conjugated 1-pyrenecarboxylic acid (COL-Py) based self-assembled magnetic nanoclusters (CMNCs), is presented. CMNCs are characterized to optimize their size, stability, and interaction dynamics with exosomes. The efficiency of CMNCs in isolating exosomes is systematically evaluated using various analytical methods to demonstrate their ability to capture exosomes based on amphiphilic lipid bilayers. CMNC-based exosome isolation consistently yields exosomes with structural integrity and purity similar to those obtained using traditional methods. The reusability of CMNCs over multiple exosome isolation cycles underscores their scalability and offers an efficient solution for biomedical applications. These results are supported by western blot analysis, which demonstrated the superiority of CMNC-based isolation in terms of purity compared to conventional methods. By providing a scalable and efficient exosome isolation process that preserves both structural integrity and purity, CMNCs can constitute a new platform that can contribute to the field of exosome studies.

[Correlation analysis of neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio and central cervical lymph node metastasis of papillary thyroid microcarcinoma]

Objective: To investigate the correlation between neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR) and central lymph node metastasis (CLNM) in patients with cN0 papillary thyroid microcarcinoma (PTMC). Methods: The clinicopathological data of PTMC patients confirmed by surgery and pathology in the 81st Military Hospital of People's Liberation Army from 2016 to 2019 were collected, and the relationship between preoperative NLR, PLR levels and postoperative PTMC CLNM were analyzed. Logistic regression analysis was used for multivariate analysis. Receiver operating characteristic (ROC) curve was used to determine the cutoff value of NLR and PLR. The interaction relative excess risk was used to analyze the relationship between NLR, PLR and CLNM. Results: Among 220 patients with cN0 stage PTMC, 92 were CLNM. The ROC curve showed that when the cutoff value of NLR was 2.5 and the cutoff value of PLR was 175, the highest Youden index was 0.318 and 0.264, respectively. NLR and PLR were both related to CLNM (P<0.05). The tumor long diameter, multifocality, NLR≥2.5 and PLR≥175 were independent impact factors of CLNM (P<0.05). The results of the interaction showed that the relative excess risk of the interaction was 5.531 (95%CI: 0.160, 10.901, P=0.016), the attribution ratio was 0.512 (95%CI: 0.230, 0.794, P=0.009), and the synergy index was 2.294 (95%CI: 1.492, 4.579, P=0.022), suggested that NLR and PLR had an interactive effect, and these two synergistically promoted CLNM. Conclusions: NLR and PLR are independent risk factors for cN0 stage PTMC CLNM. When NLR≥2.5 and PLR≥175, preventive central lymph node dissection should be routinely performed.

[Clinical outcomes of different irradiation ranges in definitive intensity-modulated radiotherapy for esophageal cancer]

Objective: To explore the therapeutic efficacy and safety of elective nodal irradiation (ENI) and involved field irradiation (IFI) in intensity-modulated radiotherapy for esophageal cancer, screen the patients suitable to undergo ENI radiotherapy and provide evidences for individual treatment of esophageal cancer. Methods: A retrospective analysis was performed on the clinical data of 924 patients with esophageal cancer who received definitive intensity-modulated radiotherapy in our hospital from January 2006 to December 2015. Among them, 272 patients received ENI and the other 652 patients received IFI. The clinicopathologic characteristics of 272 cases in ENI group and 652 cases in IFI group, who were recruited according to the balance of propensity score matching method, were compared. The Kaplan-Meier method was used to calculate 1-year, 3-years and 5-years local-regional failure-free survival (LRFFS), progression-free survival (PFS) and overall survival (OS) rates. The univariate and multivariate analysis of prognostic factors were also determined by Cox proportional hazard model and Long-rank test. Results: The clinicopathologic characteristics of these two group were not significantly different (P>0.05). The median follow-up time was 85.9 months and the follow-up rate was 95.9%. The 1-year, 3-years, 5-years PFS rates of the ENI groups were 65.3%, 31.7%, 18.4%, respectively, higher than 54.0%, 20.9%, 12.7% of the IFI group (P=0.001). The 1-year, 3-years, 5-years OS rates of the ENI groups were 79.0%, 43.7%, 24.9%, respectively, higher than 75.0%, 31.8%, 17.2% of the IFI group (P=0.003). In multivariate analysis, the sex, tumor volume, N stage and radiation field were independent factors for PFS and OS (P<0.05). Subgroup analysis showed that patients with male, age≤66 year, cervical and upper-thoracic location, tumor length≤6 cm, T1-2 stage, N0-1 stage, Ⅰ-Ⅱ stage, tumor volume≤50 cm(3), dosage>60 Gy and≤2 cycles of chemotherapy in the ENI group had a better survival rate than those in the IFI group (P<0.05). The total failure rate, local-regional failure rate in ENI group were significantly lower than those of IFI group (P=0.001, P=0.004). The incidence of bone marrow depression≥ grade 2 and 3 in ENI group was higher than that of the IFI group (P<0.05). However, the incidences of radioactive esophagitis≥ grade 3, radioactive pneumonia and late adverse reactions were not significantly different between these two groups (P>0.05). Conclusion: Compared with IFI, ENI can significantly improve the long-term survival for young, early TN stage and cervical/upper-thoracic esophageal cancer patients underwent chemotherapy.

Strong correlation between flux pinning and epitaxial strain in the GdBa2Cu3O7-x /La0.7Sr0.3MnO3 nanocrystalline heterostructure

The effect of magnetic flux pinning is investigated in GdBa₂Cu₃O₇ (GdBCO) thin films with two different types of ferromagnetic La_0.7Sr_0.3MnO₃ (LSMO) buffers (nanoparticles and a layer) deposited on an STO substrate. Magnetization analyses reveal the presence of multiple flux pinning mechanisms responsible for the improvement in the critical current density of GdBCO films. While core pinning becomes a dominant pinning mechanism in GdBCO films with LSMO nanoparticles, a hybrid effect of magnetic-volume and core-point pinning is observed in GdBCO films with LSMO layers. Examinations of local structures for both LSMO and GdBCO using extended X-ray absorption fine structure spectroscopy (EXAFS) exhibit a close relation between the parameters in the pinning force scaling and the length ratio of the Mn–O bond to the Cu–O bond. This result implies that the origin of core pinning is probably attributed to epitaxial strain induced by lattice mismatch between LSMO and GdBCO. Therefore, an appropriate strain state of LSMO is required for an effective operation of magnetic pinning.

The effect of magnetic flux pinning is investigated in GdBa₂Cu₃O₇ (GdBCO) thin films with two different types of ferromagnetic La_0.7Sr_0.3MnO₃ (LSMO) buffers (nanoparticles and a layer) deposited on an STO substrate.

Ultra-narrow linewidth quantum dot coherent comb lasers with self-injection feedback locking

We have used an external cavity self-injection feedback locking (SIFL) system to simultaneously reduce the optical linewidth of over 39 individual wavelength channels of an InAs/InP quantum dot (QD) coherent comb laser (CCL). Linewidth reduction from a few MHz to less than 200 kHz is observed. Measured phase noise spectra clearly indicate a significant decrease in phase noise in the frequency range above 2 kHz. The RF beating signal between two adjacent channels also shows a substantial reduction in 3-dB linewidth from 10 kHz to 300 Hz with the SIFL system, and a corresponding drop in baseline level (-27 dB to -50 dB).

High performance InAs/InP quantum dot 34.462-GHz C-band coherent comb laser module

We have developed an InAs/InP quantum dot (QD) C-band coherent comb laser (CCL) module with actively stabilized absolute wavelength and power, and channel spacing of 34.462 GHz with ± 100 ppm accuracy. The total output power is up to 46 mW. The integrated average relative intensity noise (RIN) values of the lasing spectrum and a filtered single channel at 1540.19 nm were -165.6 dB/Hz and -130.3 dB/Hz respectively in the frequency range from 10 MHz to 10 GHz. The optical linewidth of the 45 filtered individual channels between 1531.77 nm to 1543.77 nm ranged from 850 kHz to 2.16 MHz. We have also analyzed the noise behaviors of each individual channel.

An ultrasensitive SERS sensor for simultaneous detection of multiple cancer-related miRNAs

Simultaneous detection of multiple trace cancer associated serum miRNA biomarkers is considered as a feasible method for early cancer screening and diagnosis. In the present work, an ultrasensitive SERS sensor was prepared based on an Ag nanorod array SERS substrate by assembling special hairpin-shaped molecular beacons (MBs) for the detection of multiple lung cancer-related miRNA biomarkers. The portable SERS sensor exhibits excellent performance for the qualitative and quantitative detection of miRNAs, with advantages of ultra-sensitivity, good specificity, uniformity, reproducibility and stability, as well as remarkable reusability. By monitoring the SERS signal quenching of the MBs in the presence of target miRNA biomarkers, three lung cancer related-miRNAs (miRNA-21, miRNA-486, and miRNA-375) in buffer and human serum were simultaneously assayed using the SERS sensor array, and the limits of detection of the three miRNAs in human serum are 393 aM, 176 aM, and 144 aM, respectively. The reliable results demonstrate that the proposed SERS sensor array can be a promising candidate with great potential for the screening and clinical diagnosis of cancer in the early stage.

Facile synthesis of hydrangea flower-like hierarchical gold nanostructures with tunable surface topographies for single-particle surface-enhanced Raman scattering

The physicochemical properties of noble metal nanocrystals depend strongly on their size and shape, and it is becoming clear that the design and facile synthesis of particular nanostructures with tailored shape and size is especially important. Herein a novel class of hydrangea flower-like hierarchical gold nanostructures with tunable surface topographies and optical properties are prepared for the first time by a facile, one-pot, seedless synthesis using ascorbic acid (AA) to reduce hydrogen tetrachloroaurate (HAuCl4) in the presence of (1-hexadecyl)trimethylammonium chloride (CTAC). The morphologies of the synthesized gold nanoflowers are controlled and fine-tuned by varying the synthetic conditions such as the concentration of reagents and the growth temperature. Due to their unique hierarchical three-dimensional (3D) structures with rich hot spots, these gold nanoflowers exhibit an efficient performance in single-particle surface-enhanced Raman scattering (SERS). The work stands out as an interesting approach for anisotropic particle synthesis and morphological control, and the proposed novel, hierarchical gold nanoflowers have a number of exciting potential applications in SERS-based sensors.

Correlation between the genetic polymorphism of ORMDL3 gene and asthma risk: a meta-analysis

While increasing scientific evidence suggests that the ORMDL3 rs7216389 polymorphism may contribute to a higher susceptibility to asthma, many of the current studies have yielded inconclusive results. This meta-analysis aimed to assess the association between the ORMDL3 rs7216389 polymorphism and the risk of asthma. An extensive literature search for relevant studies was conducted in PubMed, Embase, the Web of Science, the Cochrane Library, Chinese National Knowledge Infrastructure, and Google Scholar. This meta-analysis was performed using the STATA 12.0 software. Crude odds ratios (OR) and their 95% confidence intervals (CI) were calculated. Thirteen studies were included with a total of 14,851 subjects, comprised of 6739 patients with asthma and 8112 healthy controls. Our meta-analysis results revealed that the ORMDL3 rs7216389 polymorphism may be associated with an increased risk of asthma (allele model: OR = 1.39, 95%CI = 1.27-1.52, P < 0.001; dominant model: OR = 1.46, 95%CI = 1.31-1.62, P < 0.001; recessive model: OR = 1.57, 95%CI = 1.37-1.81, P < 0.001; homozygous model: OR = 1.58, 95%CI = 1.32-1.90, P < 0.001; heterozygous model: OR = 1.54, 95%CI = 1.30-1.82, P < 0.001). We also found significant associations in our subgroup analyses based on ethnicity and type of asthma. However, in our subgroup analysis based on sources of controls, an association was found in the population-based case-control subgroup but not in the hospital-based case-control subgroup. This meta-analysis indicates that ORMDL3 rs7216389 may contribute to increasing susceptibility to asthma.

Long-term outcome of HLA-haploidentical hematopoietic stem cell transplantation without in vitro T-cell depletion based on an FBCA conditioning regimen for hematologic malignancies

Haploidentical hematopoietic stem cell transplantation (haplo-HSCT) is an alternative for patients who need a transplant without having conventional donors. One hundred and five consecutive patients with hematologic malignancies who underwent G-CSF-primed peripheral blood haplo-HSCT without in vitro T-cell depletion in our single center were reported in this study. Patients were categorized into the intermediate-risk group (n=28) or high-risk group (n=77) according to the risk stratification. The conditioning regimen included fludarabine, busulfan, cyclophosphamide and anti-lymphocyte globulin. The cumulative incidence of grades II-IV acute GvHD (aGvHD) on day +100 was 21.9%, and that of grades III-IV aGvHD was 14.3%. The 2-year cumulative incidence of total chronic GvHD (cGvHD) was 24.1%, and that of extensive cGvHD was 5.6% in 83 eligible patients. The 3-year cumulative incidence rates of relapse and no relapse mortality were 21.9% and 30.5%, respectively. After a median follow-up of 35 months, the 3-year probabilities of overall and disease-free survival for the intermediate-risk and high-risk groups were 63.2% and 39.8% and 61.2% and 32.2%, respectively. In multivariate analysis, the outcome of survival (overall survival and disease-free survival) was associated with the risk stratification, disease status at transplant and dose of infused mononuclear cells. Our results suggest that unmanipulated peripheral blood stem cell allograft performed with fludarabine, busulfan, cyclophosphamide and anti-lymphocyte globulin conditioning regimen is feasible.

Comparison of efficacy between uncovered and covered self-expanding metallic stents in malignant large bowel obstruction: a systematic review and meta-analysis

AIM

Insertion of a self-expandable metallic stent (SEMS) can rapidly relieve colorectal obstruction. This study aimed to compare the efficacy between uncovered and covered SEMSs in the treatment of malignant colorectal obstruction.

METHOD

A systematic search in Medline, Embase, the Cochrane controlled trials register and bibliographies of retrieved articles was performed. Randomized controlled trials and other comparative studies comparing uncovered and covered SEMSs for treatment of malignant colorectal obstruction were selected for this systematic review and meta-analysis. The main outcome measures were technical success, clinical success, tumour ingrowth, tumour overgrowth, early migration (≤ 7 days), late migration (> 7 days), overall complications and the duration of stent patency.

RESULTS

Compared with covered SEMSs, uncovered SEMSs were associated with a lower late migration rate (relative risk 0.25; 95% CI 0.08, 0.80; P = 0.02), a higher tumour ingrowth rate (relative risk 5.99; 95% CI 2.23, 16.10; P = 0.0004) and a prolonged stent patency (weighted mean difference 15.34 days; 95% CI 4.31, 26.37; P = 0.006). There was no significant difference in technical success, clinical success, tumour overgrowth, early migration, perforation or overall complications between the two groups.

CONCLUSION

Tumour ingrowth occurred more frequently in the uncovered SEMS group, while late migration was more common in the covered SEMS group.

Spatial and temporal expression of spermadhesin genes in reproductive tracts of male and female pigs and ejaculated sperm

Spermadhesins, a novel protein family identified in the reproductive tract of ungulates, have important roles in reproduction. In this study, the expression of pig (Sus domesticus) spermadhesion genes in seminal vesicles, prostate, and bulbourethral glands from birth to sexual maturity and the spatial expression in adult male and female genital tracts and ejaculated sperm of Meishan pigs were evaluated by reverse transcription-polymerase chain reaction (RT-PCR). In general, all spermadhesin genes increased from Days 1 to 150 in the seminal vesicle and bulbourethral gland. However, their expression in the prostate was variable; it increased from Days 1 to 60 and then declined until Day 150. In adult boars, all genes had a very high level of expression in the seminal vesicle and somewhat lower (but still relatively high) in the prostate, caput and caudal epididymides, and bulbourethral gland. Expression of AQN1 and AQN3 was not detectable in the corpus epididymis. In the testis, AQN3 gene expression was not detectable, and gene expressions were weak for AQN1, PSP-I, and PSP-II, but strong for AWN. In female pigs, most spermadhesins had low expression in the cervix, uterine horn, oviduct, and ovary. Expression of AQN1 and AQN3 was very weak in the cervix and uterine horn. Signals for AQN1 in oviduct and ovary and AQN3 in ovary were not detectable, whereas AWN had high expression in the cervix and uterine horn. In ejaculated sperm, a strong mRNA signal of spermadhesins was detected. We concluded that transcripts of spermadhesins were not only distributed extensively in male and female reproductive tissues but also in ejaculated sperm. Furthermore, their dynamic changes of expression paralleled reproductive development. Seminal vesicles were the main source of spermadhesins; when the boar reached puberty, expression of spermadhesins reached very high levels.

Mode-locked pulses from mid-infrared quantum cascade lasers

In this study, we report the unequivocal demonstration of midinfrared mode-locked pulses from quantum cascade lasers. The train of short pulses was generated by actively modulating the current and hence the gain of an edge-emitting quantum cascade laser (QCL). Pulses with duration of about 3 ps at full-width-at-half-maxima and energy of 0.5 pJ were characterized using a second-order interferometric autocorrelation technique based on a nonlinear quantum well infrared photodetector. The mode-locking dynamics in the QCLs was modeled based on the Maxwell-Bloch equations in an open two-level system. Our model reproduces the overall shape of the measured autocorrelation traces and predicts that the short pulses are accompanied by substantial wings as a result of strong spatial hole burning. The range of parameters where short mode-locked pulses can be formed is found.

Terahertz two-photon quantum well infrared photodetector

A two-photon detector based on intersubband transitions in GaAs/AlGaAs quantum wells operating in the Terahertz regime below the Reststrahlenband is reported. Resonantly enhanced optical nonlinearities enables sensitive quadratic detection at pJ pulse energies. We demonstrate its use in a quadratic autocorrelator for far-infrared picosecond pulses at around 7 THz.

TGF-beta type II receptor deficiency prevents renal injury via decrease in ERK activity in crescentic glomerulonephritis

The role of transforming growth factor-beta (TGF-beta) receptor complex in the pathogenesis of crescentic glomerulonephritis (GN) is not clear. To test the hypothesis that TGF-beta signaling plays a crucial role in the development and progression of crescentic GN by inducing the activation of extracellular signal-regulated kinase (ERK) and expression of its target genes, anti-glomerular basement membrane (GBM) GN was induced in TGF-beta type II receptor (TGF-betaIIR) gene heterozygous (TGF-betaIIR(+/-)) C57BL/6J mice and wild-type animals. GN was initiated in preimmunized mice by administration of rabbit anti-mouse GBM serum. TGF-betaIIR deficiency was significantly associated with decreased renal damage at days 14, 21, and 28 after induction of GN: renal function impairment, proteinuria, proportion of crescents, glomerular accumulation of periodic acid-Schiff-positive material, relative cortical interstitial volume, as well as renal cortical phosphorylation of ERK and plasminogen activator inhibitor type I (PAI-1) and alpha2(I) collagen mRNA levels were significantly decreased in TGF-betaIIR(+/-) mice compared with wild-type animals. These results provide the first direct evidence that TGF-betaIIR deficiency protects against renal injury in crescentic GN, possibly by inhibiting the sustained activation of ERK and PAI-1 and alpha2(I) collagen gene expression. Thus, TGF-beta signaling appears to play an important role in the development and progression of crescentic GN by inducing the ERK activity, and PAI-1 and alpha2(I) mRNA expression.

Expression and preliminary characterization of recombinant human tissue kallikrein in egg white of laying hens

Human tissue kallikrein (hK1) plays an important role in regulation of blood pressure, electrolyte and glucose transport, and renal function. To evaluate the feasibility of expression of recombinant human tissue kallikrein (rhK1) in the egg whites of laying hens, human tissue kallikrein gene (hKLK1) cDNA was subcloned into the chicken oviduct-specific expression vector (pOV3), and the resultant recombinant vector pOV3K was injected into laying hens via wing vein after mixing with polyethyleneimine. Following injection twice with the recombinant vector, the enzymatic activity at a maximal level of 59 U/mL was detected in the egg whites, which lasted for more than 7 d. The expression level of rhK1 in the egg whites in the 3-mg group was relatively higher than that in the 2-mg group, but the significant differences were identified on d 7 and 8 (P < 0.05). Ten days after the primary injection, the hens were reinjected with the same dose of the vector, and even higher enzymatic activity was detected in their egg whites. Two different breeds of hen were tested with no difference in expression level found (P > 0.05). Western blot analysis of the egg whites from vector-injected hens showed the rhK1 was recognized by a polyclonal antibody specific for hK1 with molecular weights of 37 and 43 kDa, which probably corresponded to the mature and preenzyme, respectively. Biochemical studies showed that the recombinant enzyme had a similar thermostability, optimal pH, hypotensive effect, and sensitivity to different ions to the natural enzymes in human and porcine tissues. These data indicate that the chicken oviduct-specific transient expression system can produce relatively high level and authentic recombinant enzyme with a potential for further development for therapeutic use.

Functional expression of a recombinant copper/zinc superoxide dismutase of filarial nematode, Brugia malayi

A gene encoding a copper/zinc superoxide dismutase (Cu/ Zn-SOD) of a filarial nematode, Brugia malayi, has been isolated and the biochemical properties of a functionally expressed recombinant enzyme were investigated. The cloned complementary DNA contained a single open reading frame of 477 bp encoding 158 amino acids (aa), which conserved metal-binding residues as well as residues specific for Cu/Zn-SODs. Comparison of the deduced aa sequence of the enzyme with that of other helminthes species, including filarial worms, exhibited high degree of similarities (49-98%). Recombinant enzyme of 32 kDa had an isoelectric point of 6.6 and was shown to consist of 2 subunits linked by interchain disulfide bonds. Enzyme activity of the recombinant protein was inhibited by potassium cyanide and hydrogen peroxide but not by sodium azide. It showed a wide range of pH optima, i.e., 7.0-11.0 and was highly resistant to heat inactivation.

Coupled electron-phonon modes in optically pumped resonant intersubband lasers

Intersubband lasing at 12-16 microm based on a CO2 laser pumped stimulated resonant Raman process in GaAs/AlGaAs three-level double-quantum-well structures is reported. The presence, or lack of, lasing action provides evidence for resonantly coupled modes of collective electronic intersubband transitions and longitudinal optical phonons. An anticrossing behavior of these modes is clearly seen when the difference between the pump and lasing energies (i.e., Stokes Raman shift) is compared with the subband separation. This work reveals the significance of the strong coupling between intersubband transitions and phonons and raises a new possibility of realizing a phonon "laser."

PCR-RFLP based molecular typing of enteroviruses isolated from patients with aseptic meningitis in Korea

We have evaluated PCR-RFLP as a practical method for rapid typing of enteroviruses causing aseptic meningitis in Korea. Through blind examination of 80 clinical isolates from patients with aseptic meningitis, we have compared the results of conventional serotyping with PCR-RFLP based genotyping, which was developed for this study. Among the 80 case isolates, which had been previously typed by routine neutralization test, only 42 cases (52.5%) were matched with typing by PCR-RFLP. The result clearly demonstrated that the enterovirus serotype does not coincide with the genotype. Therefore, the classification of enteroviruses by genotyping with PCR-RFLP, although rapid and simple, may be complicated by regional or seasonal differences. However, the PCR-RFLP method developed in this study is applicable to the epidemiological study of enteroviruses when regional or seasonal differences exist, and is useful in identifying the source of an infection.

Repair of triplex-directed DNA alkylation by nucleotide excision repair

Triplex-forming oligonucleotides (TFOs) are being investigated as highly specific DNA binding agents to inhibit the expression of clinically relevant genes. So far, they have been shown to inhibit transcription from the HER-2/neu gene in vitro, whereas their use in vivo has been studied to a limited extent. This study uses a TFO-chlorambucil (chl) conjugate capable of forming site-specific covalent guanine adducts within the HER-2/neu promoter. We demonstrate that nucleotide excision repair (NER) represents a mechanism of cellular resistance to TFO-directed DNA alkylation. In vitro repair assays demonstrate that triplex-directed chl-guanine adducts are substrates for repair by NER competent cell extracts but not XP12BE cell extracts deficient in NER. The degree of repair is estimated by a ligation-mediated polymerase chain reaction with a pre-formed triplex in a plasmid transfected into repair competent cells, indicating that approximately 25% of the guanine adducts are removed after 24 h. These data indicate that guanine adducts from TFO-directed alkylation are a substrate for NER and that DNA repair is a significant barrier to the intracellular persistence of target gene binding by TFOs.

Oxytocin mediates the inhibitory action of acute lithium on the morphine dependence in rats

The role of central oxytocin in inhibitory action of lithium on the development of morphine dependence was behavioral investigated in rats. Acute lithium could enhance the morphine-induced analgesia in rats with or without chronic morphine treatment; this effect could be inhibited by intraventricular injection of oxytocin antagonist d (CH(2))(5)-Tyr (Me)-[Orn(8)]-Vasotocin (OVT). Lithium could attenuate naloxone-precipitated withdrawal signs in morphine dependent rats. The reduction of the expression of naloxone-precipitated withdrawal signs by lithium was reversed by ICV of OVT. The lithium significantly inhibited the conditioned place preference (CPP) induced by morphine, which inhibitory action of lithium could also reverse by ICV injection of OVT. These results suggested that lithium might inhibit the physical dependence on morphine as well as psychological dependence in rats, and that this inhibitory effect of lithium on the development of morphine dependence might be associated with oxytocin systems in the central nervous system.

mRNA expression of urokinase and plasminogen activator inhibitor-1 in human crescentic glomerulonephritis

AIMS

Weak staining for urokinase-plasminogen activator (uPA), tissue type plasminogen activator (tPA), or plasminogen activator inhibitor-1 (PAI-1) confined to crescents has been described in a few cases of severe crescentic glomerulonephritis. We evaluated the molecular mechanism by which these proteins are increased or induced within crescents.

METHODS AND RESULTS

We examined uPA, tPA and PAI-1 mRNA expression in 12 renal biopsies with crescentic glomerulonephritis, and in six control renal biopsies with no detectable abnormalities by RNA in-situ hybridization. The expressions of uPA, tPA and PAI-1 proteins were also assessed by immunofluorescence. To better determine the cellular origin of uPA and PAI-1 transcripts, CD68 protein was studied by immunohistochemistry on the same sections on which in-situ hybridization had been performed. In controls, there were very low level signals of uPA and PAI-1 mRNAs in a few glomerular epithelial cells (GECs). Specific signals of uPA and PAI-1 mRNAs were detected in the cells forming crescents in all the cases with crescentic glomerulonephritis. However, weak expression of mRNA for tPA was detected in two cases only. Immunostaining for uPA and PAI-1 was positive in some but not all, cases of crescentic glomerulonephritis. A double-labelling study showed that the signal for PAI-1 and uPA mRNAs was mainly in CD68- cells.

CONCLUSIONS

Local accumulation of uPA or PAI-1 in crescents is associated with enhanced mRNA expression of these proteins. The up-regulation of PAI-1 mRNA by GECs, in particular, could play a major role in the formation of persistent fibrin deposits and progression of the lesions in crescents. Whether up-regulation of uPA is an epiphenomenon or plays a pathogenic role in the formation of crescents remains to be clarified.

[Production of transgenic lamb integrated with modified human anti-trypsin gene]

This experiment is to produce the human mAAT(modified anti-trypsin) which cures the emphysema specifically through mammalian galactophore of transgenic goat. 56 goats were selected as donor for superovulation by FSF + LH microinjection in this experiment. The pronucleic embryos were injected with human mAAT gene after fertilization in vivo, and transferred to the donors or receptors directly. The superovulation was better in March and May than in December with the number of ovulation of 19.50, 21.70 and 16.06, and number of fertilized embryos of 4.31, 6.48 and 3.57 per-animal respectively. The pregnant rates were 18.18% and 25% respectively after transferred to donors and receptors with natural estrus. The donors also can be used as the embryo receptor with no remarkable decrease of pregnant rate. 29 lamb were labored. 4 positive transgenic lamb were checked by PCR, PCR-Southern and Southern analysis. The integrated efficiency of foreign DNA was 13.79% with microinjection of high copy number of foreign DNA fragment.

Advanced glycosylation end products stimulate collagen mRNA synthesis in mesangial cells mediated by protein kinase C and transforming growth factor-beta

Advanced glycosylation end products (AGE) seem to be implicated in the pathogenesis of diabetic nephropathy. The present study has examined the effects of AGE on protein kinase C (PKC) activity and transforming growth factor-beta1 (TGF-beta1) in relation to collagen gene regulation in cultured human mesangial cells (HMCs). Quiescent HMCs were exposed to serum-free media containing bovine serum albumin (BSA), AGE-modified BSA (AGE-BSA), or glycated BSA in which AGE formation was prevented by the use of aminoguanidine (BSA-AM). AGE-BSA (200 microg/mL) induced a peak membrane-associated PKC activity, particularly PKC-a, at 4 hours. AGE-BSA stimulated alpha1(I) and alpha1(IV) collagen mRNA expression after 24-hour incubation with HMCs, which remained elevated until hour 60. HMCs incubated with AGE-BSA induced a significant inhibition of cell proliferation compared with cells incubated with BSA. AGE-BSA stimulated TGF-beta mRNA and protein expression in HMCs. The TGF-beta secreted by HMCs was shown by CCL-64 mink lung cell assay to be bioactive. In contrast, BSA-AM did not affect either collagen or TGF-beta mRNA or protein expression in HMCs. The stimulatory effects of AGE-BSA on collagen gene regulation in HMCs could be negated by the pretreatment of HMCs with GF 109203X for 30 minutes or with phorbol myristate acetate for 24 hours before AGE-BSA administration. Neutralizing antibody to TGF-beta inhibited increased collagen mRNA expression by HMCs exposed to AGE-BSA. These results suggest that AGE-BSA stimulates collagen mRNA expression by activating PKC and the transcriptional upregulation of TGF-beta1 in HMCs. Thus, PKC and TGF-beta may function as key signaling intermediaries in the AGE-up-regulated collagen gene expression pathway in HMCs.

The expression of G-protein-gated inwardly rectifying K+ channels GIRK1 and GIRK2 mRNAs in the supraoptic nucleus of the rat and possible role involved

The expression of G-protein-gated inwardly rectifying K channels subunits GIRK1 and GIRK2 mRNAs in the supraoptic nucleus (SON) was investigated in the rat by in situ hybridization with non-radioactive dig-labeled cRNA probes. Double-labeled methods were used to study the co-localization of GIRK1 and 2 and oxytocin (OT) and vasopressin (AVP) in the SON. The present study revealed wide and intense expression of GIRK1 and GIRK2 mRNAs with high overlapping in the SON, indicating the heterologous channel of GIRK1/GIRK2 was a major functional channel in the SON. Given that 100% of OT-positive and 95% of (AVP)-positive neurons in the SON expressed GIRK1/GIRK2 mRNAs, it is possible that GIRK1/GIRK2 channel, activated through G-protein coupled receptors, may be involved in the inhibitory regulation of the release of OT and AVP from the SON.

Frequency of CYP2A6 gene deletion and its relation to risk of lung and esophageal cancer in the Chinese population

Cytochrome P450 2A6 (CYP2A6) plays an important role in the oxidation of nicotine and in the activation of tobacco-related carcinogens, such as N-nitrosodimethylamine, N-nitrosodiethylamine and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone. It has been suggested that individuals with defective CYP2A6 alleles are at a lower risk of becoming smokers and of developing lung and other tobacco-related cancers. We examined the relationship between the CYP2A6 gene deletion and susceptibility to lung and esophageal cancer in a Chinese population via a hospital-based case-control study. The CYP2A6 gene deletion was determined by a PCR-based approach in 326 healthy controls, 149 patients with esophageal squamous-cell carcinoma and 151 patients with lung cancer. The allele frequency of the CYP2A6*4 deletion was 8.6% among controls compared with 8.4% among cases with esophageal squamous-cell carcinoma (p = 0.29) or 13.2% among cases with lung cancer (p < 0.01). Individuals who harbored at least one CYP2A6*4 deletion allele were at a 2-fold increased risk of developing lung cancer (95% confidence interval [CI] = 1.2-3.2) compared with those without a defective CYP2A6 allele. This effect was mainly limited to squamous-cell carcinoma and to non-smokers, although a joint effect of CYP2A6 deletion and tobacco smoking on lung cancer risk was observed among heavy smokers. The overall risk of esophageal cancer did not appear to be associated with this CYP2A6 genetic polymorphism (odds ratio [OR] = 1.2, 95% CI = 0.7-2.1). However, stratified analysis suggested an excess risk with borderline significance (OR = 2.1; 95% CI = 1.0-4.5) related to the CYP2A6*4 allele among non-smokers. The distribution of CYP2A6 genotype frequency was not significantly different (p = 0.40) between smokers (n = 174) and non-smokers (n = 152) in this study population. Our results demonstrate that the CYP2A6 gene deletion is associated with an increased risk of lung and esophageal cancer but not with a reduced tendency to smoke.

Frequency of CYP2A6 gene deletion and its relation to risk of lung and esophageal cancer in the Chinese population

Cytochrome P450 2A6 (CYP2A6) plays an important role in the oxidation of nicotine and in the activation of tobacco-related carcinogens, such as N-nitrosodimethylamine, N-nitrosodiethylamine and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone. It has been suggested that individuals with defective CYP2A6 alleles are at a lower risk of becoming smokers and of developing lung and other tobacco-related cancers. We examined the relationship between the CYP2A6 gene deletion and susceptibility to lung and esophageal cancer in a Chinese population via a hospital-based case-control study. The CYP2A6 gene deletion was determined by a PCR-based approach in 326 healthy controls, 149 patients with esophageal squamous-cell carcinoma and 151 patients with lung cancer. The allele frequency of the CYP2A6*4 deletion was 8.6% among controls compared with 8.4% among cases with esophageal squamous-cell carcinoma (p = 0.29) or 13.2% among cases with lung cancer (p < 0.01). Individuals who harbored at least one CYP2A6*4 deletion allele were at a 2-fold increased risk of developing lung cancer (95% confidence interval [CI] = 1.2-3.2) compared with those without a defective CYP2A6 allele. This effect was mainly limited to squamous-cell carcinoma and to non-smokers, although a joint effect of CYP2A6 deletion and tobacco smoking on lung cancer risk was observed among heavy smokers. The overall risk of esophageal cancer did not appear to be associated with this CYP2A6 genetic polymorphism (odds ratio [OR] = 1.2, 95% CI = 0.7-2.1). However, stratified analysis suggested an excess risk with borderline significance (OR = 2.1; 95% CI = 1.0-4.5) related to the CYP2A6*4 allele among non-smokers. The distribution of CYP2A6 genotype frequency was not significantly different (p = 0.40) between smokers (n = 174) and non-smokers (n = 152) in this study population. Our results demonstrate that the CYP2A6 gene deletion is associated with an increased risk of lung and esophageal cancer but not with a reduced tendency to smoke.

[Observation of plasma levels of beta-endorphin in patients with trigeminal neuralgia]

OBJECTIVE

To observe the relationship between plasma levels of beta-endorphin and trigeminal neuralgia.

METHODS

During the attacks of trigeminal neuralgia, beta-endorphin levels of plasma from external jugular, cubital fossa vein blood ipsilateral to the pain and contralateral external jugular vein blood were assessed by sensitive radioimmunoassay in 12 cases, after operations the venous blood from the ipsilateral external jugular vein was sampled again, the external jugular vein blood of 12 normal volunteers was collected as control.

RESULTS

The plasma levels of beta-endorphin in patients with trigeminal neuralgia were significantly lower than that in normal volunteers (P<0.05).

CONCLUSION

The lowered plasma beta-endorphin levels may be an important factor for the development of pain in patients with trigeminal neuralgia, which may result in pain and neurogenic inflammation that can not be controlled in central nervous system and peripheral nerve terminals.

Characterization and pathogenetic role of proteinase from Acanthamoeba castellanii

A secreted proteinase was purified from the culture supernatant of Acanthamoeba castellanii with several chromatographic steps. The purified proteinase was a chymotrypsin-like serine proteinase. Its molecular weight was approximately 12 kDa on SDS-PAGE, and its native molecular weight was 12 kDa when determined by molecular sieve chromatography. It showed a broad temperature optimum ranging 30-55 degrees C with an optimal at 55 degrees C and an optimal pH of 8.5. It could degrade various protein substrates, such as collagen, fibronectin, laminin, secretory immunoglobulin A, immunoglobulin G, plasminogen, fibrinogen, haemoglobin and rabbit corneal proteins. It showed strong cytopathic effects in cultured cells, including HEp2 and HEK cells. The corneal lesions, induced by both the purified proteinase and A. castellanii, displayed similar clinical results for both cases, in which the stromal infiltration and opacity with the epithelial defect were revealed. These results suggest that the enzyme was highly associated with the pathogenesis of Acanthamoeba. The fact that cytopathic effects and development of corneal lesions caused by the proteinase of Acanthamoeba were inhibited by the proteinase inhibitor suggest that the proteinase inhibitor might be useful as a therapeutic agent.

Purification and characterization of iron superoxide dismutase and copper-zinc superoxide dismutase from Acanthamoeba castellanii

Two superoxide dismutases (SOD I and SOD II) were purified from Acanthamoeba castellanii and characterized for several biochemical properties. Analysis of the primary structure and inhibition studies revealed that SOD I is iron SOD (Fe-SOD), with a molecular mass of 50 kDa, and SOD II is copper-zinc SOD (Cu,Zn-SOD), with a molecular mass of 38 kDa. Both enzymes have a homodimeric structure consisting of 2 identical subunits, each with a molecular mass of 26 and 19 kDa for SOD I and SOD II, respectively. The isoelectric points of SOD I and SOD II were 6.4 and 3.5, respectively, and there were no isoenzyme forms detected. Both enzymes show a broad optimal pH of 7.0-11.0. Because no differences were observed in the apparent molecular weight of SOD I after addition of the reducing agent 2-mercaptoethanol, the subunits do not appear to be linked covalently by disulfide bonds. However, the subunits of SOD II were covalently linked by intra- and interdisulfide bonds. Western blot analyses showed that the 2 enzymes have different antigenicity. Both enzymes occur as cytoplasmic and detergent-extractable fractions. These enzymes may be potential virulence factors of A. castellanii by acting both as antioxidants and antiinflammatory agents. These enzymes may be attractive targets for chemotherapy and immunodiagnosis of acanthamoebiasis.

Chronic morphine treatment inhibits oxytocin synthesis in rats

The changes of oxytocin content and mRNA expression in some nuclei were investigated in morphine-dependent rats using radioimmunoassay (RIA) and in situ hybridization (ISH). After chronic administration of morphine, the oxytocin content in supraoptic nucleus (SON) and nucleus accumbens (NAc) decreased, and increased in the ventral tegment area (VTA) and locus coeruleus (LC), but did not change in other nuclei including the paraventricular nucleus (PVN), lateral septum (SEPTUM), raphe magnus nucleus (NRM) and periaquaductal gray (PAG). In morphine-L dependent rats, naloxone increased the levels of oxytocin in SON and PVN, but decreased that in LC. ISH first showed that chronic morphine treatment inhibited the oxytocin synthesis in SON but not in PVN. The present study demonstrates that chronic morphine treatment alters the brain oxytocin system, suggesting that oxytocin might contribute to the behavioral and neuroendocrine responses to morphine.

Mixed chimera converted into full donor chimera with powerful graft-versus-leukemia effects but no graft-versus-host disease after non T cell-depleted HLA-mismatched peripheral blood stem cell transplantation

Instead of donor T cell depletion, we used CTLA4 and TJU103 (a small organic compound believed to block CD4 binding to MHC II molecule of APC) to block donor T lymphocyte activation in vitro before infusion, and mycophenolate mofetil to control the activity of lymphocytes of the recipient. We successfully treated a patient with an HLA-mismatched graft without donor T cell depletion. Mixed chimerism was observed 30 days and 60 days after transplantation. STR-PCR showed that 28% and 62% of blood mononuclear cells (MNC) were donor derived at day +30 and day +60, respectively. Mixed chimerism converted into full donor chimerism, when 99.7% of the MNC in the recipient were donor derived after three courses of DLI. A powerful GVL effect related to mixed chimerism was observed. No acute GVHD occurred, only grade II chronic GVHD occurred 6 months after transplant. Based on this case, we suggest that: (1) stable mixed chimerism can be intentionally established across HLA barriers without donor T cell depletion; (2) mixed chimerism can be converted into full donor chimerism by DLI; (3) mixed chimerism induced with this approach can be associated with a very powerful GVL effect, and these may be enhanced by DLI, without severe GVHD.

Purification and characterization of an extracellular serine proteinase from Acanthamoeba castellanii

An extracellular proteinase of Acanthamoeba castellanii was purified and its biochemical and pathological properties were characterized. The molecular mass of the purified enzyme was approximately 42 kDa as estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Sephacryl S-200 HR gel-filtration chromatography. Therefore, its structure seemed to be monomeric with a single polypeptide. Its activity was inhibited by the serine proteinase inhibitors diisopropyl fluorophosphate and phenylmethanesulfonyl fluoride. Its activity was optimum at 30 to 50 degrees C with a maximum at 50 degrees C; optimal pH was 8.0. As much as 70% of the enzyme activity was maintained at 50 degrees C for at least 12 h but was rapidly inactivated thereafter. The purified enzyme degraded collagen and rabbit corneal extract. Furthermore, it exhibited strong cytopathic effects on human corneal epithelial cells and fibroblast cells. These suggest the possible role of this enzyme in the pathogenesis of Acanthamoeba.

Cloning and expression of a cysteine proteinase gene from Paragonimus westermani adult worms

A gene encoding a cysteine proteinase from Paragonimus westermani has been cloned and expressed in Escherichia coli. The cysteine proteinase cDNA fragment was amplified by reverse transcription-polymerase chain reaction (RT-PCR) using degenerate oligonucleotide primers derived from the conserved active site of the cysteine proteinase. The 5' and 3' regions of the gene were amplified using a PCR technique for the rapid amplification of cDNA ends. The cloned gene has an open reading frame of 687 bp and deduced amino acid sequence of 229. Sequence analysis and alignment showed significant homologies with the eukaryotic cysteine proteinases and conservation of the Cys, His, and Asp residues that form a catalytic triad. Analysis of the expressed protein on sodium dodecyl sulfate polyacrylamide gel electrophoresis showed that the molecular weight of the protein was approximately 28.5 kDa. The expressed protein reacted with the sera of patients with paragonimiasis but not with the sera of fascioliasis and clonorchiasis. These results suggest that the expressed protein may be valuable as a specific diagnostic material for the immunodiagnosis of paragonimiasis.

Amniotic membrane patching promotes healing and inhibits proteinase activity on wound healing following acute corneal alkali burn

Amniotic membrane (AM) contains basement membrane components and various proteinase inhibitors. Furthermore, when used as a graft, the basement membrane of AM could block inflammatory insults to a damaged corneal surface. Thus, we evaluated whether amniotic membrane patching could promote the healing process by inhibiting proteolytic damage. Alkali wounds were inflicted on the central corneas of rabbits by applying a round filter paper, 6.0 mm in diameter, soaked in 1 N NaOH for 30 sec. Amniotic membrane patching was performed over the perilimbal sclera immediately after wounding. A total of 115 rabbits were divided into four groups: (1) immediately covered by AM with the amnion cell side down up to the perilimbal sclera (n =26); (2) covered by AM with the stromal side down up to the perilimbal sclera (n =19); (3) anchored to the fornix (n =29); and (4) uncovered as a control (n =41). AM was removed 3 days postoperatively. During follow-ups, epithelial defects, corneal thickness and its opacity of each eye were measured. Some corneas were removed for histopathologic studies and for proteinase activity assay and zymography. The epithelial healing was faster and the corneal thickness was thicker in all three AM-covered groups than in the control (P<0.05). No significant difference was found between covered and anchored groups (P>0.05). Corneal opacity was least in the amnion cell side down group. Infiltration of polymorphonuclear leukocytes (PMNs) was much less in AM-covered groups than in the control. Pathological results were associated with zymographic findings, which revealed much higher proteinase activity in uncovered group than AM-covered groups. Immediate intervention for acute alkali burns with AM as a temporary patch promotes wound healing by inhibiting proteinase activity and PMNs infiltration.

Use of monoclonal antibody in diagnosis of candidiasis caused by Candida albicans: detection of circulating aspartyl proteinase antigen

To develop a serological diagnosis of invasive candidiasis based on detection of circulating secreted aspartyl proteinase (SAP) antigen of Candida albicans, three different enzyme-linked immunosorbent assays (ELISAs) were compared. The first was a standard ELISA to detect anti-SAP antibodies, and the others were an antigen capture ELISA and an inhibition ELISA to detect circulating SAP antigen with monoclonal antibody (MAb) CAP1, which is highly specific for SAP. These tests were applied to 33 serum samples retrospectively selected from 33 patients with mycologically and/or serologically proven invasive candidiasis caused by C. albicans. Serum samples from 12 patients with aspergillosis and serum samples from 13 healthy individuals were also included. The sensitivities and specificities were 69.7 and 76.0% for the standard ELISA and 93.9 and 92.0% for the antigen capture ELISA, respectively. However, these values reached 93.9 and 96.0%, respectively, for the inhibition ELISA. Serum samples from 31 of 33 patients had detectable SAP antigen, with concentrations ranging from 6.3 to 19.0 ng/ml. These results indicate that the inhibition ELISA with MAb CAP1 is effective in detection of circulating SAP antigen and that this assay may be useful for diagnosis and treatment monitoring of invasive candidiasis.

Production, characterization, and epitope mapping of a monoclonal antibody against aspartic proteinase of Candida albicans

A monoclonal antibody (MAb; MAb CAP1) that was reactive with extracellular aspartic proteinase of Candida albicans (CAP) was produced. The MAb showed strong sensitivity and reactivity to CAP but not to the aspartic proteinases of Candida parapsilosis, Candida tropicalis, and Aspergillus fumigatus or to human cathepsin D or porcine pepsin. The epitope of the CAP recognized by the MAb was the proteinaseous part of CAP and the putative epitope of the MAb was located in the Asp77 to Gly103 sequence. This antibody could be useful for the characterization of CAP and would be a valuable probe for the detection of CAP antigen in the sera of patients with invasive candidiasis.

Dynorphin A enhances mitogen-induced proliferative response and interleukin-2 production of rat splenocytes

It has been well known that immune function is modulated by endogenous opioid peptides: beta-endorphin and enkephalins. However, the effect of dynorphin A on the immune function has not been well documented. In this study, we investigated dynorphin A in the regulation of mitogen-induced proliferation and and interleukin-2 (IL-2) production of rat splenocytes. The results showed that dynorphin A 1-13 as well as dynorphin A 1-17 enhanced concanavalin A-stimulated [(3)H] thymidine uptake 46-112% and IL-2 production in a dose-dependent fashion. These effects were reversed by naloxone and norBNI, a selective kappa-receptor antagonist. Dynorphin A reduced cyclic AMP contents in spenocytes in naloxone and norBNI reversible fashion. The data suggest that dynorphin A enhanced mitogen-stumulated lymphocyte proliferation and IL-2 production via kappa-opioid receptor and cAMP pathway.

[Effect of anti-opioid peptide sera on the enhancement of electroacupuncture analgesia induced by neurotensin in PAG of rats]

With the use of potassium iontophoresis induced tail-flick for measuring the pain threshold, the effects of injecting neurotensin (NT), naloxone (NX), anti-metenkephalin serum (AMEKS), anti-beta-endorphin serum (AEPS) and anti-dynorphin A1-13 serum (ADYNS) into periaqueductal gray (PAG) on electroacupuncture (EA) analgesia in rats were investigated. NT administration enhanced EA analgesia remarkably. Pre-injection of NX, AMEKS and AEPS into PAG could significantly attenuate the enhancement of EA analgesia induced by NT, but not by administration of ADYNS. The results indicate that NT in PAG is responsible for the enhancement of EA analgesia. The effect of NT may be partly mediated by met-enkephalin and beta-endorphin.

Extracellular and cytosolic iron superoxide dismutase from Mycobacterium bovis BCG

Two forms of iron superoxide dismutase (SOD) were purified from cell extract (CE) and culture filtrate (CF) of Mycobacterium bovis BCG, respectively. The molecular weight of both enzymes was estimated to be approximately 84,000 by gel filtration, whereas that of their subunits was 21,500, as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, indicating that each of purified enzymes is composed of four identical subunits. The specific activities of CE SOD and CF SOD were 3,850 and 4,040, respectively. The purified enzymes were not joined by disulfide bonds and were, to some extent, resistant to sodium dodecyl sulfate. Their activities were lost by H2O2, but not by azide and cyanide, indicating iron SODs. Enzyme activities were detectable over a broad range of pHs, from 5.0 to 9.0, and were stable for 6 months at -20 degreesC. Each value of pI was 4.5. In Western blots, both enzymes reacted with sera of tuberculosis patients, but not with normal sera. The N-terminal amino acid sequences of CE SOD and CF SOD were the same, suggesting that there is no N-terminal signal sequence.

Factors affecting transformation efficiency of BCG with a Mycobacterium-Escherichia coli shuttle vector pYUB18 by electroporation

BCG has been one of the vehicles for multi-recombinant vaccine. However, low transformation efficiency of BCG with plasmid DNA hampered studies involving expression of foreign antigens in BCG. In an effort to determine the optimal conditions, this study was initiated to investigate factors involved in the transformation of BCG with a Mycobacterium-Escherichia coli shuttle vector, pYUB18, by electroporation. Mycobacterium bovis BCG (strain 1173P2) was grown in Middlebrook (M) 7H9 broth containing albumin-dextrose-catalase and 0.05% tween 80, and transformed BCG was grown in M7H10 agar containing kanamycin for counting viable cells. Pretreatment of BCG with 10 mM CaCl2 improved the transformation efficiency, but overnight incubation of BCG with 1% glycine did not. The transformation efficiency in BCG also varied depending on voltage, resistance, and DNA concentration. The maximum transformation efficiency was obtained when the infinity resistance, 12.5 Kv/cm, and 100 ng of DNA were used, and reached 1.4 x 10(5) CFU/microgram of plasmid DNA, which is about 3-100 times greater than those from previous reports. The transformation conditions described in this study, therefore, will give us a better position for employing BCG as a vehicle for developing multi-recombinant vaccines.

[Possible mechanism of the analgesic effect of interleukin-2 in central nervous system]

The monoclonal antibody against IL-2R (Tac) could not block the analgesic effect of IL-2, and IL-2 mutant that could not bind to beta subunit of IL-2 receptor still had capability of increasing the pain threshold of rats. All these facts suggest that the analgesic effect of IL-2 in CNS is not mediated through the IL-2 receptor, and that the immune and analgesic effects of IL-2 are mediated through different receptor mechanisms. It is suggested that there are common antigenic determinants and similar structure between IL-2 and endogenous opioid peptides (EOP). This implies that the analgesic effect of IL-2 might be mediated by interaction between IL-2 and opioid receptors in CNS. Using radioimmunoassay the contents of EOP of different nuclei were measured at different times after injecting IL-2 into the lateral ventricle of rats. The results suggested that the analgesic effect of IL-2 may be related to beta-EP and LEK in arcuate hypothalamic nucleus, paraventricular hypothalamic nucleus and locus ceruleus.

[Role of locus coeruleus in analgesia caused by stimulation of supraoptic nucleus]

The effects of stimulation of supraoptic nucleus (SON) on the changes of oxytocin (OT), arginine vasopressin (AVP), norepinephrine (NE) and serotonin (5-HT) in the perfusate of locus coeruleus (LC) and changes of pain threshild (PT) were studied by methods of microinjection, radioimmunoassay (RIA) and high pressure liquid chromatography (HPLC) technique. The results showed that the OT contents at 30, 60 and 90 min after stimulation, that of AVP at 30 min and 5-HT at 60 min were increased significantly, while the NE contents at 30 and 60 min were decreased markedly. Injection of V1 antagonist into LC did not affect the analgesic effect caused by administration of L-glutamic acid (L-Glu) into SON, which, however, could be partially inhibited by V2 antagonist or even reversed by OT antagonist. The above results suggested that the analgesic effect due to stimulation of SON is caused by increase of 5-HT and decreases of NE in the LC though the action of OT released by SON on OT and V2 receptor in LC.

Characterization of a cysteine proteinase from adult worms of Paragonimus westermani

Paragonimus westermani, the lung fluke, is known to migrate to the pulmonary tissue of mammalian hosts and causes pathological changes in the lungs. An acidic thiol-dependent proteinase with a molecular weight of approximately 20,000 daltons was purified to homogeneity using ion-exchange chromatography and gel filtration chromatography. On SDS-PAGE, the molecular weight of the enzyme was 17,500 daltons. Isoelectric point was 6.45. The enzyme was similar to the acidic cysteine proteinase of vertebrates in the properties of pH 5.5 for at least two days when stored at 4 degrees C. The cysteine proteinase was capable of degrading collagen and hemoglobin. Sera of patients with paragonimiasis and mice infected with P. westermani reacted in immunoblots with the partially purified proteinase. This result suggested that the cysteine proteinase of P. westermani may play a role in migration in tissues, and in acquisition of nutrients by parasites from the host. It is also potentially an antigen for the serodiagnosis of paragonimiasis.

Antinociceptive effect of intracerebroventricular injection of a tetrapeptide Asn-Ala-Gly-Ala in rats

The antinociceptive effect of intracerebroventricular injection (icv) of Asn-Ala-Gly-Ala (NAGA), a partial sequence of beta-lipotropin, was studied in rats. The potassium iontophoresis-induced tail flick was used to measure the pain threshold. The antinociceptive effect of NAGA, which was dose-dependent (icv, 0.03-0.24 mumol/rat) and long-lasting (90 min), was reversed by naloxone (icv, 0.26 mg.kg-1) and inhibited by anti-MEK serum (titre: 1:5000, 5 microliters) or anti-LEK serum (titre: 1:5000, 5 microliters). NAGA-induced antinociception was scarcely affected by anti-beta-EP serum (titre: 1:30,000, 5 microliters) or anti-Dyn A1-13 serum (titre: 1:30,000, 5 microliters). It was suggested that the antinociceptive effect of NAGA may be associated with the release of met-enkephalin and leu-enkephalin in rat brain.

Purification and partial characterization of cysteine proteinase from Spirometra mansoni plerocercoids

Spirometra mansoni plerocercoids were dissected from the tissues of naturally infected snakes (Natrix trigrialateralia). Fresh plerocercoids were incubated in medium, and excretory-secretory products (E-S) were collected. In addition, soluble proteins from lyophilized plerocercoids (10 mg/ml) were extracted in 0.1 M sodium acetate. Proteinase activity was assayed with a synthetic fluorescent substrate, carbobenzoxy-phenylalanyl-arginyl-7-amino-4-trifluoromethylcoumarin. Proteinase was isolated from plerocercoid extract or E-S by diethylaminoethyl trisacryl M ion-exchange chromatography and thiolpropyl-Sepharose affinity chromatography. These separations resulted in a 12.2- (extract) and 15.6-fold (E-S) purification of proteinase. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the purified materials revealed a 28-kDa band, consistent with the apparent native molecular weight (gel filtration chromatography) of approximately 35 kDa. Proteinases purified from whole extracts and E-S were compared for various biochemical characteristics; inhibitor profiles indicated that activities from both sources are cysteine proteinases, they exhibited identical pH curves with optima at pH 5.5 and a 50% activity range at pH 4.7-8.0, they cleaved collagen chains to 3 identical products, and they showed only minor activity toward hemoglobin. Further, the proteinase purified from plerocercoids was utilized in immunoblots with sera from sparganosis patients. Antibody (IgG) from the infected patients, but not uninfected controls, recognized the cysteine proteinase, suggesting that this antigen may be useful in the serodiagnosis of Spirometra mansoni infection.