[Function of modified YSI membrane in glucose sensor]

This study was designed to improve the stability, accuracy and interference resistance of the glucose sensor system and to fomodify the correlation between electrode current and glucose concentration. Catalase was immobilized in YSI membrane. Experiments in vitro were conducted in different concentrations of glucose or ascorbic acid or paracetomol. The results showed the background current, 0.37 +/- 0.06 nA; the drift values in 0 mM G.S. and 10 mM G.S. were (0.20 +/- 0.14)%/30 hr and (3.22 +/- 0.40)%/30 hr respectively. The mean value of drift in 10 mM G.S. was 0.103% mM-1hr-1. The correlation between electrode current and glucose concentration gave satisfaction (r = 0.986); it ranged from 0 mM G.S. to 20 mM G.S. Lower concentration of ascorbic cid could not interfere n the glucose sensor system; higher concentration of ascorbic acid and paracetomol only produced very low interference current. These suggest that the modified YSI membrane contributes greatly to a stable, accurate and reliable glucose sensor system.

The molecular chaperone alphaA-crystallin enhances lens epithelial cell growth and resistance to UVA stress

alphaA-Crystallin (alphaA) is a member of the small heat shock protein (sHSP) family and has the ability to prevent denatured proteins from aggregating in vitro. Lens epithelial cells express relatively low levels of alphaA, but in differentiated fiber cells, alphaA is the most abundant soluble protein. The lenses of alphaA-knock-out mice develop opacities at an early age, implying a critical role for alphaA in the maintenance of fiber cell transparency. However, the function of alpha-crystallin in the lens epithelium is unknown. To investigate the physiological function of alphaA in lens epithelial cells, we used the following two systems: alphaA knock-out (alphaA(-/-)) mouse lens epithelial cells and human lens epithelial cells that overexpress alphaA. The growth rate of alphaA(-/-) mouse lens epithelial cells was reduced by 50% compared with wild type cells. Cell cycle kinetics, measured by fluorescence-activated cell sorter analysis of propidium iodide-stained cells, indicated a relative deficiency of alphaA(-/-) cells in the G2/M phases. Exposure of mouse lens epithelial cells to physiological levels of UVA resulted in an increase in the number of apoptotic cells in the cultures. Four hours after irradiation the fraction of apoptotic cells in the alphaA(-/-) cultures was increased 40-fold over wild type. In cells lacking alphaA, UVA exposure modified F-actin, but actin was protected in cells expressing alphaA. Stably transfected cell lines overexpressing human alphaA were generated by transfecting extended life span human lens epithelial cells with the mammalian expression vector construct pCI-neoalphaA. Cells overexpressing alphaA were resistant to UVA stress, as determined by clonogenic survival. alphaA remained cytoplasmic after exposure to either UVA or thermal stress indicating that, unlike other sHSPs, the protective effect of alphaA was not associated with its relocalization to the nucleus. These results indicate that alphaA has important cellular functions in the lens over and above its well characterized role in refraction.

Effects of ginseng treatment on neutrophil chemiluminescence and immunoglobulin G subclasses in a rat model of chronic Pseudomonas aeruginosa pneumonia

Chronic Pseudomonas aeruginosa lung infection in cystic fibrosis (CF) patients is almost impossible to eradicate with antibiotic treatment. In the present study, the effects of treatment with the Chinese herbal medicine ginseng on blood polymorphonuclear leukocyte (PMN) chemiluminescence and serum specific antibody responses were studied in a rat model of chronic P. aeruginosa pneumonia mimicking CF. An aqueous extract of ginseng was administered by subcutaneous injection at a dosage of 25 mg/kg of body weight/day for 2 weeks. Saline was used as a control. Two weeks after the start of ginseng treatment, significantly increased PMN chemiluminescence (P Collapse

Key Words Collapse

MESH Headings

• Animals
• Antibodies, Bacterial/blood
• Bronchoalveolar Lavage Fluid/cytology
• Cystic Fibrosis/complications
• Disease Models, Animal
• Female
• Immunoglobulin G/blood
• Luminescent Measurements
• Lung/pathology
• Macrophages, Alveolar/immunology
• Macrophages, Alveolar/metabolism
• Neutrophil Activation
• Neutrophils/immunology
• Panax/therapeutic use
• Phytotherapy
• Plant Extracts/therapeutic use
• Plants, Medicinal
• Pneumonia, Bacterial/drug therapy
• Pneumonia, Bacterial/immunology
• Pneumonia, Bacterial/pathology
• Pseudomonas Infections/drug therapy
• Pseudomonas Infections/immunology
• Pseudomonas Infections/pathology
• Pseudomonas aeruginosa/immunology
• Rats
• Rats, Inbred Lew
• Respiratory Burst

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[Study on the interaction between Cu2+ and cholesterol by spectrometric analysis]

With four kinds of spectrometric analysis methods, i.e. spectrophotometric analysis, AAS, ICP-AES and IR, the interaction between Cu2+ and cholesterol in aqueous solution has been examined. The same results from the different methods showed that there was a surface adsorption between Cu2+ and cholesterol and this interaction would be prominent in physiology-like situation.

[Pulsatile microdialysis method with glucose sensor system]

To develop a miniature subcutaneous glucose sensor system, to simplify calibration procedure before or after glucose monitor, and to improve its temperature characteristics, a pulsatile micropump and the microdialysis technique were used. The experiments of glucose recovery in 5.5 mM and 10 mM G.S. and the temperature experiment from 20 degrees C to 40 degrees C were conducted. The results showed that glucose recovery was (97 +/- 2)%, the current values of glucose sensor varied with temperature, but the temperature parameter was only 3.4%. These indicate that the glucose sensor system is miniature and the calibration procedure is simple. Because of its modified temperature characterisic, it is useful to monitor the blood glucose of feverish diabetics.

[Effects of subcutaneous injection with different doses of ginseng on the rat model of chronic Pseudomonas aeruginosa pneumonia]

OBJECTIVE

To observe the effect of ginseng extracts on a rat model of chronic Pseudomonas aeruginosa (PA) pneumonia.

METHODS

Subcutaneous injection with four different doses of ginseng aqueous extracts to the model rats for two weeks.

RESULTS

Milder macroscopic lung pathology and lower incidence of lung abscesses were found in all the four groups received different doses of ginseng treatment compared to the control group (P < 0.05). Histopathology of the lungs was negatively correlated with the ginseng doses (r = -0.95, P < 0.01). The mast cell number in the lung foci in group I, II and IV was significantly lower than that in the control group (P < 0.05). Bacterial clearance in group II and group III was enhanced significantly (P < 0.05) compared with that in the control group. The specific antibody responses were down-regulated in group II, III and IV (P < 0.01), and IgM level in group I was lower compared to the control group (P < 0.01). Serum IgM level was positively correlated with the ginseng doses (r = 0.93, P < 0.05). IgG2a titer in group I was higher than that in the control group (P < 0.05). Serum IgG2a level was positively correlated with the ginseng doses (r = 0.90, P < 0.02). Two weeks after PA lung infection, the serum level of IgG against PA, aeruginosa alginate in group I, II, and III was higher than that in the control and group IV (P < 0.05), and the anti-alginate IgA level in group I, III and IV was lower than that in the control (P < 0.05).

CONCLUSIONS

The ginseng dose of 2.5 mg/kg was the best dosage in the present study, and it showed an effect of stimulating T helper type I response.

Antibiotic activities and affinities for bacterial cell wall analogue of N-demethylvancomycin and its derivatives

N-Demethylvancomycin, which has been clinically used in China, is one member of vancomycin group (glycopeptide) antibiotics. It differs from vancomycin only in that methyl group on the amino group of the N-terminal residue of vancomycin has been replaced by H. By reductive alkylation of N-demethylvancomycin, we synthesized N-alkyl and N,N'-dialkyl N-demethylvancomycins, which closely correlated with vancomycin in structure. The association constants of the complexes of N-demethylvancomycin and its analogues with di-N-Ac-L-Lys-D-Ala-D-Ala and the antibiotic activity against Staphylococcus aureus of the glycopeptides were determined. Results showed that N-demethylvancomycin has higher affinity for bacterial cell wall analogue di-N-Ac-L-Lys-D-Ala-D-Ala and more potent antibiotic activity against Staphylococcus aureus than vancomycin. Both N-alkylation and N,N'-dialkylation of N-demethylvancomycin reduced the affinity and antibiotic activity. The longer the alkyl groups, the less potent antibiotic activities and lower affinities have the glycopeptides. The antibiotic activities against Staphylococcus aureus of N-demethylvancomycin and its analogues roughly parallel their affinities for di-N-Ac-L-Lys-D-Ala-D-Ala.

[Indirect sensitized upconversion in Tm3+ and Yb3+ codoped non-crystal pentaphosphate]

We report the blue upconversion luminescence of Tm3+ and Yb3+ codoped non-crystal pentaphosphate pumped by -798nm laser diode. The samples were directly excited to 3F4 level of Tm3+ ion. Two energy transfer processes between Tm3+ and Yb3+ contribute mainly to the population of 1G4 level of Tm3+. Phonon plays an important role in the upconversion process.

Expression of growth control and differentiation genes in human lens epithelial cells with extended life span

PURPOSE

Peptide growth factors including hepatocyte growth factor (HGF), platelet-derived growth factor (PDGF), and epidermal growth factor (EGF) are mitogens for many cell types and may act as regulators of lens epithelial cell growth and differentiation. The present study was undertaken to investigate the expression of growth factor receptors and crystallin genes in the human lens epithelial cell line HLE B-3, created by infection with Adeno12-simian virus 40 (Ad12-SV40) hybrid virus.

METHODS

Reverse transcriptase-polymerase chain reaction (RT-PCR) with gene-specific primers was used to detect transcripts, and Southern and western blot analyses were used for identification of gene products. Functional analysis of PDGF receptor was performed by measuring the effect of PDGF-BB on Ca2+ release, cell growth, and western blot analysis, by using an antiphosphotyrosine antibody.

RESULTS

Human lens epithelial B-3 cells expressed the growth factor receptors HGF-R, EGF-R, and PDGF-Rbeta, but not PDGF-Ralpha, and also expressed the oncogenes H-ras and raf and the growth inhibitor transforming growth factor-beta1. Stimulation of PDGF-Rbeta with PDGF-BB in HLE B-3 cells increased phosphorylation of the receptor, was associated with an increase in intracellular Ca2+ levels, and produced a small increase in cell growth. In addition, HLE B-3 cells expressed transcripts for alphaA-, alphaB-, and betaB2-crystallins, and expressed the corresponding proteins. The transcripts for alphaA-crystallin decreased markedly at higher passages.

CONCLUSIONS

The above findings suggest that the increased growth potential of human lens epithelial cells by Ad12-SV40 infection maintained certain lens-specific properties and response to PDGF.

[Three-dimensional volumetric display--a new application of frequency up-conversion]

This paper discusses the present research situation and the application prospect of 3-D volumetric display technology. The possible usability and science significance of frequency up-conversion in 3-D volumetric display field are also demonstrated systematically. In ZBLAN: Pr, Yb glasses, we primarily demonstrated and achieved a new application of frequency up-conversion three dimensional volumetric display, using the two-frequency up-conversion of the rare earth ions. The efficiency of luminescence of Pr was enhanced much by the energy transfer between Pr and Yb ions.

[Study on the NIR-Raman spectra and NIR-SERS spectra of amsacrine]

The near infrared surface-enhanced Raman spectra (NIR-SERS) of amsacrine,an anticancer agent, on silver collids were recored with high quality. The NIR-SERS enhancement factor is up to 10(4) magnitude. In comparison with the near infrared Raman (NIR-Raman) spectra of solid amsacrine, more information of vibrational structures of amsacrine molecules at low concentration and almost in its practical application envi ronment, can be given by the NIR-SERS. The enhancement mechanism is associated with the adsorption of acridyl ring and sulfonyl on silver surface.

Sialic-acid-binding lectin from the slug Limax flavus--cloning, expression of the polypeptide, and tissue localization

A cDNA library of Limax flavus was constructed and screened for sialic-acid-specific lectins. Complementary DNA clones were categorized into seven groups corresponding to closely related but different sequences. Group 1 clones contained an ORF encoding 199 amino acids including a sequence identical to the partial amino acid sequence obtained from the lectin protein. Within its 1074-bp 3' untranslated region, ten closely related 60-bp sequence repeats were found. Group 2 clones contained an ORF encoding a polypeptide chain of the same number of amino acid residues, with 89.1% overall identity to that of the group 1 and eight 60-bp repeat sequences in the 3' untranslated region. The remaining groups of clones contained ORF with highly similar full or partial sequences, with or without 60 bp repeats in the 3' untranslated region. The large number of closely related but different cDNA clones obtained indicated that the slug sialic-acid-specific lectin gene is a member of a multigene family. The lectin amino acid sequence showed significant similarity with the fibrinogen domain of human tenascin-C, with a human C-type serum lectin, and with pig ficolin. Immunostaining analysis of slug tissue for the lectin indicated that it is present primarily on the epidermal surface and in mucous glands. Recombinant slug lectin protein lacking the 20-amino-acid N-terminal signal sequence produced in a bacterial expression system from a group-1 clone accumulated as aggregates in inclusion bodies, suggesting that large-scale production of the active agglutinin may be possible.

Clinical evaluation of a new generation membrane oxygenator: a prospective randomized study

A new generation hollow-fibre membrane oxygenator (Spiral Gold) has been introduced by Baxter Healthcare (Irvine, CA, USA). The purpose of this study was to evaluate the operational performance of this device under clinical conditions and to compare it to the Univox Gold membrane oxygenator. Following institutional review board approval, and the obtainment of informed consent, 26 patients undergoing coronary artery bypass grafting were randomly assigned to either a Spiral Gold (Spiral) (n = 13) or Univox Gold (Univox) (n = 13) group. Study parameters were grouped into the following categories: haematological, haemodynamic, oxygenator performance and perioperative outcomes. All patients received identical surgical, anaesthesia and postoperative care. There were no statistically significant differences in either preoperative or operative parameters between groups. During cardiopulmonary bypass, the Spiral group had a significantly lower pressure drop (26.9 +/- 8.2 vs 46.7 +/- 16.2 mmHg, p < 0.001). The Spiral group had significantly lower plasma free haemoglobin levels during all time periods of CPB compared to the Univox group. Heat exchange coefficients were higher during the rewarming period in the Spiral patients (0.59 +/- 0.28) compared to the Univox group (0.36 +/- 0.19), p = 0.06. There were no differences in oxygen transfer between groups, but ventilation gas sweep rates and FiO2 levels were statistically lower in the Spiral group at two of the three sampling time periods. The ratio of ventilating gas sweep rate to blood flow rate was lower in the Spiral group (0.56 +/- 0.12) compared to the Univox group (0.74 +/- 0.23), p < 0.03. The Spiral Gold oxygenator had superior oxygen transfer efficiency and lower haemolysis rates than the Univox Gold oxygenator.

[Spectroscopic characterization of a new terbium complex with red fluorescence]

Usually, the emission spectra of terbium complexes exhibit 490 nm, 545 nm bands (green color) under the excitation of UV light, which is ascribed to the two 5D4 - 7F6, 5D4 - 7F5 transition. In this report, pink red fluorescence under the excitation of 300-370nm UV light is observed for a new 1, 10-phenanthroline-2-naphthoate complex of terbium. The fluorescence, FT-IR, ICP and X-ray fluorescence analysis were performed. The results showed that under the perturbation of the ligands field, the probability of 5D4 - 7F3 transition of terbium ion was greatly enhanced, while the probability of 5D4 - 7F5 transition was greatly decreased in the complex. Therefore, pink-red fluorescence was observed for the title complex.

[Spectrofluorimetric study of trifluoroacetylacetone (TFA)-gadolinium(III)-CTMAB system and application]

The determination of microamount gadolinium(III) by fluorescence method was studied based on complex formation Gd(III)-CTMAB-TFA at pH7.2. Beer's law is obeyed in the range of 0. 005-0.04 microg/mL Gd(III). The detection limit is 0.003 microg/mL. The method is used to determine microamount gadolinium of rare-earth mine with satisfactory result, and compared with that of ICP-AES method.

Studies of multimerin in human endothelial cells

Multimerin is a novel, massive, soluble protein that resembles von Willebrand factor in its repeating, homomultimeric structure. Both proteins are expressed by megakaryocytes and endothelial cells and are stored in the region of platelet alpha-granules resembling Weibel-Palade bodies. These findings led us to study the distribution of multimerin within human endothelial cells. Multimerin was identified in vascular endothelium in situ. In cultured endothelial cells, multimerin was identified within round to rod-shaped, dense-core granules, some of which contained intragranular, longitudinally arranged tubules and resembled Weibel-Palade bodies. However, multimerin was found primarily in different structures than the Weibel-Palade body proteins von Willebrand factor and P-selectin. After stimulation with secretagogues, multimerin was observed to redistribute from intracellular structures to the external cellular membrane, without detectable accompanied secretion of multimerin into the culture media. In early passage endothelial cell cultures, multimerin was associated with extensive, fibrillary, extracellular matrix structures, in a different distribution than fibronectin. Although multimerin and von Willebrand factor are stored together in platelets, they are mainly found within different structures in endothelial cells, indicating that there are tissue-specific differences in the sorting of these soluble, multimeric proteins.

[Spectral study of podophyllotoxin and its derivatives]

In this paper, we have studied all kinds of static absorption spectra and transient absorption spectra of podophyllotoxin and its derivatives. We have located the site of absorption spectra and their forming mechanism with spectrofluorometry, Ultraviolet, pulse radiolysis and laser photolysis, and suggested the connection of their structrue with their anti-tumour and toxicity.

[Study of portable synchronous ECG recorder and its long-distance communication system]

This paper presents a convenient long-distance ECG communication system. It is made up of portable ECG recorder, hospital work station and public telephone network. This paper also introduces a kind of modulation and demodulation method in sound coupling communication-pulse edge modulation and demodulation. This system has rational structure, convenient operation and strong management power. A Philips 80C552 used as CPU in the recoder which is portable, cheap and reliable.

Clinical comparison of pulsatile and nonpulsatile perfusion during cardiopulmonary bypass

Controversy exists concerning the utilization of pulsatile flow during cardiopulmonary bypass (CPB) with regard to improved patient outcomes. The purpose of the present study was to evaluate pulsatile perfusion in patients undergoing CPB in a clinical setting. Seventy patients undergoing open heart surgery for repair of valvular or congenital heart disease were prospectively entered into the study and were randomly assigned to either pulsatile perfusion (PP, n = 35) or nonpulsatile perfusion (NP, n = 35) groups. All patients received identical surgical, perfusion, and postoperative care. Study parameters included: rate of spontaneous cardiac conversion, inotropic drug use, urine output, skin temperature, platelet count, fibrinogen concentration, and plasma free hemoglobin level. There were no statistically significant differences seen in either preoperative or operative parameters between groups. The PP group had a significantly higher rate of spontaneous cardiac conversion, less inotropic drug use, earlier recovery of skin temperature, and higher urine output during CPB (908.8 +/- 87.2 ml/hr vs. 606.1 +/- 57.5 ml/hr, p < .01). There were no significant differences in either platelet count or fibrinogen concentration between groups. There was a steady increase in plasma free hemoglobin during PP, which was not seen in the NP group (p < .01). We conclude that the use of pulsatile flow resulted in improved patient outcomes in maintaining better renal function and preserving cardiac function in the early post-bypass period.

Cellular immune responses to orthopaedic implant materials following cemented total joint replacement

In vitro cellular immune responses to metallic and polymeric implant materials in particulate form were measured preoperatively in 185 patients. The patients were candidates for either primary total joint replacement (n = 65) or revision arthroplasty (n = 120). Proliferative cellular responses to polymethylmethacrylate particles in patients with osteoarthritis at revision surgery for aseptic loosening were significantly higher than the responses of patients with osteoarthritis at either primary surgery or surgical revision for mechanical failure of the prosthesis or sepsis. The responses to particles of cobalt-chromium alloy at revision surgery were also higher than the responses at primary surgery. The responses were reevaluated in 32 patients after a minimum of 10 months following surgery to correlate individual changes in the biological responses with clinical progress. Reevaluation at early follow-up of patients who had undergone primary surgery revealed significantly elevated proliferative responses and in vitro cytokine production in response to polymethylmethacrylate and cobalt-chromium alloy particles compared with their preoperative responses. In contrast, the response at follow-up to polymethylmethacrylate was significantly reduced in patients who had undergone revision surgery, and this reduction corresponded with a marked improvement in pain, joint motion, and function following revision surgery. These data suggest that specific cellular responses to polymethylmethacrylate or cobalt-chromium alloy particles, or both, may be associated with loose or painful prostheses.

Chronic Pseudomonas aeruginosa lung infection is more severe in Th2 responding BALB/c mice compared to Th1 responding C3H/HeN mice

The chronic Pseudomonas aeruginosa lung infection in cystic fibrosis (CF) is characterized by a pronounced antibody response and microcolonies surrounded by numerous polymorphonuclear neutrophils (PMN). Poor prognosis is correlated with a high antibody response to P. aeruginosa antigens. An animal model of this infection was established in two strains of mice: C3H/HeN and BALB/c, generally known as Th1 and Th2 responders, respectively, which were challenged with alginate-embedded P. aeruginosa. Mortality was significantly lower in C3H/HeN compared to BALB/c mice (p < 0.025). P. aeruginosa was cleared more efficiently in C3H/HeN mice and significantly more C3H/HeN mice showed normal lung histopathology (p < 0.02), and we found significantly fewer microabscesses in C3H/HeN mice than in BALB/c mice (p < 0.005). In supernatants from P. aeruginosa antigen and concanavalin A-stimulated spleen cells from the two strains of mice, the interferon-(IFN-) gamma levels were higher, whereas IL-4 levels were lower in C3H/HeN mice than in BALB/c mice. The implications of these findings for CF patients with chronic P. aeruginosa lung infection are discussed.

Optical resolution of DL-alanine by using immobilized Aspergillus oryzae cells

Mycelium pellets with diameters of 1-2 mm and containing abundant aminoacylase were obtained by the liquid fermentation of Aspergillus oryzae 3042. By the cross-linking method with reagents of gelatin and formaldehyde, the immobilized A. oryzae cells (IAC) were prepared with much higher activity and reactive properties. The effects of factors on enzymatic activity of IAC were investigated. When substrate concentration was less than 0.15 mol/L, the Michaelis-Menten mechanism was suitable for this reaction.

Conformational transitions of the phosphodiester backbone in native DNA: two-dimensional magic-angle-spinning 31P-NMR of DNA fibers

Solid-state 31P-NMR is used to investigate the orientation of the phosphodiester backbone in NaDNA-, LiDNA-, MgDNA-, and NaDNA-netropsin fibers. The results for A- and B-DNA agree with previous interpretations. We verify that the binding of netropsin to NaDNA stabilizes the B form, and find that in NaDNA, most of the phosphate groups adopt a conformation typical of the A form, although there are minor components with phosphate orientations close to the B form. For LiDNA and MgDNA samples, on the other hand, we find phosphate conformations that are in variance with previous models. These samples display x-ray diffraction patterns that correspond to C-DNA. However, we find two distinct phosphate orientations in these samples, one resembling that in B-DNA, and one displaying a twist of the PO4 groups about the O3-P-O4 bisectors. The latter conformation is not in accordance with previous models of C-DNA structure.

Primary structure and functional expression of heavy- and light-chain variable region genes of a monoclonal antibody specific for human fibrin

The immunoglobulin heavy- and light-chain variable region (VH and VK) genes were isolated from 8E5 hybridoma cells, which secreted monoclonal antibody against human fibrin by RT-PCR. An expression vector pOPE51-8E5 was constructed for the recombinant VH-VK scFv expression. The primary sequence of the variable regions was determined. Expression product was found in the periplasmic space and inclusion bodies by SDS-PAGE and immunoblotting. It was a 30 KDa single chain fragment (scFv) with the antigen-binding specificity of the parental monoclonal antibody. A light chain shuffling with an unspecific VL did not result in a loss of fibrin binding specificity.

[Cloning and expression of heavy- and light-chain variable region genes of monoclonal antibody specific for human fibrin]

OBJECTIVE

To obtain the minimum molecule having activity to bind human fibrin.

METHODS

The immunoglobulin heavy- and light-chain variable region (VH and Vkappa) genes were isolated from 8E5 hybridoma cells, which secreted a monoclonal antibody against human fibrin, by RT-PCR. An expression vector pOPE51-8E5 was constructed for the recombinant VH-Vkappa expression. The transformed E. coli JM 109 cells were propagated and induced by IPTG.

RESULTS AND CONCLUSION

Expression product was found in the periplasmic space and inclusion bodies by SDS-PAGE and immunobloting. It was a 30000 single chain fragment (scFv) with antigen-binding specificity. The yield of the scFv was 28.9% of the total bacterial proteins.

Ginseng treatment reduces bacterial load and lung pathology in chronic Pseudomonas aeruginosa pneumonia in rats

The predominant pathogen in patients with cystic fibrosis (CF) is Pseudomonas aeruginosa, which results in a chronic lung infection associated with progressive pulmonary insufficiency. In a rat model of chronic P. aeruginosa pneumonia mimicking that in patients with CF, we studied whether the inflammation and antibody responses could be changed by treatment with the Chinese herbal medicine ginseng. An aqueous extract of ginseng was injected subcutaneously, and cortisone and saline were used as controls. Two weeks after challenge with P. aeruginosa, the ginseng-treated group showed a significantly improved bacterial clearance from the lungs (P < 0.04), less severe lung pathology (P = 0.05), lower lung abscess incidence (P < 0.01), and fewer mast cell numbers in the lung foci (P < 0.005). Furthermore, lower total immunoglobulin G (IgG) levels (P < 0.01) and higher IgG2a levels (P < 0.025) in serum against P. aeruginosa sonicate and a shift from an acute type to a chronic type of lung inflammation compared to those in the control and cortisone-treated groups were observed. These findings indicate that ginseng treatment of an experimental P. aeruginosa pneumonia in rats promotes a cellular response resembling a TH1-like response. On the basis of these results it is suggested that ginseng may have the potential to be a promising natural medicine, in conjunction with other forms of treatment, for CF patients with chronic P. aeruginosa lung infection.

[Biological characteristics of residual leukemic cells and their drug-resistant regrowth]

OBJECTIVE

To elucidate the mechanisms of residual leukemia and its drug-resistant regrowth.

METHODS

Bone marrow cells from transplantable mouse leukemia models L615 and L7811 were cultivated in long-term culture system respectively. Daunorubicin (DNR) was added to the systems to mimick in vivo chemotherapy.

RESULTS

Residual leukemic cells on stromal layers escaped DNR killing. They derived from the adherent leukemic cell population, which was heterogeneous with many undifferentiated and dormant cells. They were drug-resistant and expressed bcl-2 gene.

CONCLUSION

Bone marrow stromal layer was the vital microenvironment for the residual leukemic cells to survive and regrow, and might increase the drug-resistance by up-regulating bcl-2 gene expression.

[Study on the interaction between CP and DNA]

In this paper, interaction between CP (Cis-ddp or ciplatin) and DNA (deoxyribonucleicacid) was studied using the fluorescence probe as well as the absorption spectra of DAN.

[Molfig, a software for displaying the structure and vibration of molecule]

A Molfig software has been developed for displaying the structure and vibrational mode of molecule in our lab. Various functions and a friendly interface are equipped in the software. The testing results showed that the software may enhance our understanding of the relationship between the vibrational behavior and the structure of molecules.

[Curvefit, an overlapping bands resolving software for IR spectra]

A Curvefit software has been developed for resolving the overlapping band of the vibartional spectra in our lab . Various functions and a friendly interface are equipped in the software. The testing results showed that both the speed of the calculation and the reliability of the final results are satisfactory.

DCP-1, a Drosophila cell death protease essential for development

Apoptosis, a form of cellular suicide, involves the activation of CED-3-related cysteine proteases (caspases). The regulation of caspases by apoptotic signals and the precise mechanism by which they kill the cell remain unknown. In Drosophila, different death-inducing stimuli induce the expression of the apoptotic activator reaper. Cell killing by reaper and two genetically linked apoptotic activators, hid and grim, requires caspase activity. A Drosophila caspase, named Drosophila caspase-1 (DCP-1), was identified and found to be structurally and biochemically similar to Caenorhabditis elegans CED-3. Loss of zygotic DCP-1 function in Drosophila caused larval lethality and melanotic tumors, showing that this gene is essential for normal development.

T cell receptor (V beta) bias in the response of rheumatoid arthritis synovial fluid T cells to connective tissue antigens

T cell receptor (V beta) use in the response to type II collagen and cartilage proteoglycans was analysed in peripheral blood and synovial fluid T cells from RA patients. T cells from RA patients with an immune response to connective tissue antigens, and paired PB and SF samples were stimulated in vitro with type II collagen, high density aggrecan proteoglycans (PG), and the T cell mitogen concanavalin A. After short term culture, mRNA was extracted from cells and a reverse transcription-polymerase chain reaction was performed, using primers specific for eight TCR V beta determinants. Blood cells stimulated with ConA generated strong bands with virtually all the V beta primers tested, but the TCR (V beta) expression by SF T cells stimulated with mitogen was biased, suggesting a selection process during joint infiltration. The V beta phenotypes of cells responding to PG was restricted in individual RA patients, but the pattern of V beta use in the the RA population was not consistent. In contrast, the V beta phenotypes of SF cells responding to CII was highly biased in both individual patients and the RA population, with V beta 14, V beta 17, and V beta 8 phenotypes predominant. We conclude that the T cell response to connective tissue antigens is restricted compared with mitogen stimulation, with the highest degree of TCR bias seen in the response of SF T cells to stimulation with type II collagen.

[Comparative test on spawn culture materials of Poria cocos]

It saves much time, work and timber when Poria cocos spawn is made from cottonseed hulls and pine sawdust. Compared with the yields from pine wood chip, the difference is not significant.

Biology and genetics of atopic disease

Several immunological disorders including allergic rhinitis, bronchial asthma, atopic dermatitis, food allergies, urticaria, nonhereditary angioedema, systemic anaphylaxis, and allergic conjunctivitis are associated with a positive family history, and share a positive response in the Prausnitz-Kuster (wheal and flare) reaction. Studies have shown that 20-30% of the population has a strong genetic predisposition for this condition, termed atopy, whose hallmark is a greatly elevated serum IgE concentration. A great deal is known about the cellular interactions that mediate the sensitization, immediate and late-phase reactions that follow encounters with allergen, as well as about the cell surface and signaling events that result in mediator release from inflammatory cells. Less is known of the genes that confer genetic predisposition for atopy; however, a worldwide effort to identify atopy genes is making significant progress.

FTIR studies of recombinant human granulocyte-macrophage colony-stimulating factor in aqueous solutions: secondary structure, disulfide reduction and thermal behavior

Fourier transform infrared spectroscopy (FTIR) has been used to investigate the secondary structure, disulfide reduction and thermal behavior of recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) in aqueous solutions. The contributions of amino-acid side-chain groups to the amide I bands of rhGM-CSF in H2O and in D2O solutions were carefully scrutinized, as 40% of the total 127 amino-acid residues of rhGM-CSF is side-chain absorptive (asparagine, glutamine, etc.). The FTIR results indicated that rhGM-CSF is composed of 46% alpha-helix, 7% beta-sheet, 23% turn and 24% loop/irregular structures which are in good agreement with the X-ray diffractional data. Reduction of rhGM-CSF with dithiothreitol caused apparent unfolding of the native conformation followed by the time-dependent increase of beta-aggregation bands which arose at 1622 and 1693 cm(-1) in H2O, 1613 and 1684 cm(-1) in D2O solutions. The result also showed that tertiary structure can change independently of the secondary structure. Thermal denaturation of rhGM-CSF took place at 55 to 70 degrees C and the denatured protein adopted an irregular structure as revealed by the FTIR spectra. The thermal denaturation did not show the formation of intermolecular beta-aggregates which is typical of most thermal denatured proteins. Moreover, it is partly reversible, indicating a special thermal stability of rhGM-CSF.

Effects of Chinese medicinal herbs on a rat model of chronic Pseudomonas aeruginosa lung infection

The aim of the study was to evaluate the effects of two kinds of Chinese medicinal herbs, Isatis tinctoria L (ITL) and Daphne giraldii Nitsche (DGN), on a rat model of chronic Pseudomonas aeruginosa lung infection mimicking cystic fibrosis (CF). Compared to the control group, both drugs were able to reduce the incidence of lung abscess (p < 0.05) and to decrease the severity of the macroscopic pathology in lungs (p < 0.05). In the great majority of the rats, the herbs altered the inflammatory response in the lungs from an acute type inflammation, dominated by polymorphonuclear leukocytes (PMN), to a chronic type inflammation, dominated by mononuclear leukocytes (MN). DGN also improved the clearance of P. aeruginosa from the lungs (p < 0.03) compared with the control group. There were no significant differences between the control group and the two herbal groups with regard to serum IgG and IgA anti-P. aeruginosa sonicate antibodies. However, the IgM concentration in the ITL group was significantly lower than in the control group (p < 0.03). These results suggest that the two medicinal herbs might be helpful to CF patients with chronic P. aeruginosa lung infection, DGN being the most favorable.

Polymorphic nucleotides within the human IL-4 promoter that mediate overexpression of the gene

Atopy, which predisposes individuals to develop asthma, severe systemic anaphylaxis, and atopic dermatitis, is usually associated with dramatically elevated total serum IgE levels and is thought to be controlled by a major susceptibility gene and multiple minor susceptibility genes. A recent sib-pair analysis revealed a tight linkage between markers on 5q31.1 and a major susceptibility gene controlling total serum IgE levels. Due to its location within this cluster and its biologic role in Ig class switching and Th2 cell differentiation, the IL-4 gene has emerged as one major candidate for the atopy gene. In one model, polymorphisms within IL-4 regulatory elements might result in overexpression of the gene, amplifying Th2 cell differentiation and class switching to IgE. In support of this model, we report that the human IL-4 promoter exists in multiple allelic forms that exhibit distinct transcriptional activities in IL-4-positive T cells. A particular allele has an unusually high transcriptional activity. A nucleotide substitution within a recently described OAP40 element located just upstream of an NF-AT site (P sequence) appears to be largely responsible for the increased promotor strength of this particular allelic form of the IL-4 promoter. In EMSAs, this substitution results in a markedly enhanced affinity for sequence-specific complexes exhibiting an AP-1 specificity. The identification of allelic nucleotides, which results in overexpression of the IL-4 gene, provides specific targets for a comprehensive screening of atopic and nonatopic individuals and may provide a clue for genetic predisposition for atopy.

Polymorphic nucleotides within the human IL-4 promoter that mediate overexpression of the gene

Atopy, which predisposes individuals to develop asthma, severe systemic anaphylaxis, and atopic dermatitis, is usually associated with dramatically elevated total serum IgE levels and is thought to be controlled by a major susceptibility gene and multiple minor susceptibility genes. A recent sib-pair analysis revealed a tight linkage between markers on 5q31.1 and a major susceptibility gene controlling total serum IgE levels. Due to its location within this cluster and its biologic role in Ig class switching and Th2 cell differentiation, the IL-4 gene has emerged as one major candidate for the atopy gene. In one model, polymorphisms within IL-4 regulatory elements might result in overexpression of the gene, amplifying Th2 cell differentiation and class switching to IgE. In support of this model, we report that the human IL-4 promoter exists in multiple allelic forms that exhibit distinct transcriptional activities in IL-4-positive T cells. A particular allele has an unusually high transcriptional activity. A nucleotide substitution within a recently described OAP40 element located just upstream of an NF-AT site (P sequence) appears to be largely responsible for the increased promotor strength of this particular allelic form of the IL-4 promoter. In EMSAs, this substitution results in a markedly enhanced affinity for sequence-specific complexes exhibiting an AP-1 specificity. The identification of allelic nucleotides, which results in overexpression of the IL-4 gene, provides specific targets for a comprehensive screening of atopic and nonatopic individuals and may provide a clue for genetic predisposition for atopy.

Inhibition of NF-AT-dependent transcription by NF-kappa B: implications for differential gene expression in T helper cell subsets

Activation of individual CD4+ T cells results in differential lymphokine expression: interleukin 2 (IL-2) is preferentially produced by T helper type 1 (TH1) cells, which are involved in cell-mediated immune responses, whereas IL-4 is synthesized by TH2 cells, which are essential for humoral immunity. The Ca(2+)-dependent factor NF-ATp plays a key role in the inducible transcription of both these lymphokine genes. However, while IL2 expression requires the contribution of Ca(2+)- and protein kinase C-dependent signals, we report that activation of human IL4 transcription through the Ca(2+)-dependent pathway is diminished by protein kinase C stimulation in Jurkat T cells. This phenomenon is due to mutually exclusive binding of NF-ATp and NF-kappa B to the P sequence, an element located 69 bp upstream of the IL4 transcription initiation site. Human IL4 promoter-mediated transcription is downregulated in Jurkat cells stimulated with the NF-kappa B-activating cytokine tumor necrosis factor alpha and suppressed in RelA-overexpressing cells. In contrast, protein kinase C stimulation or RelA overexpression does not affect the activity of a human IL4 promoter containing a mouse P sequence, which is a higher-affinity site for NF-ATp and a lower-affinity site for RelA. Thus, competition between two general transcriptional activators, RelA and NF-ATp, mediates the inhibitory effect of protein kinase C stimulation on IL4 expression and may contribute to differential gene expression in TH cells.

[Chemical constituents of Clematis intricata Bunge]

Five compounds were isolated from the aerial part of Clematis intricata for the first time. On the basis of spectral data (UV, IR, MS, 1HNMR and 13CNMR), they were identified as scopoletin, caffeic acid, inositol, 1-tria-contanol and beta-sitosterol.

Expression and function of beta 1 integrins on adherent and nonadherent Ehrlich ascites tumor cells

Differences in integrin-mediated cell-matrix adhesion between two types of Ehrlich ascites tumor (EAT) cells, adherent and nonadherent EAT cells, have been studied. The adherent EAT (a-EAT) cells adhere to and spread on laminin- or fibronectin-coated plates, whereas the nonadherent EAT (na-EAT) cells do not. The adhesion of a-EAT cells to laminin or fibronectin requires the presence of both Ca2+ and Mg2+. Anti-human fibronectin receptor (alpha 5 beta 1 integrin) antiserum blocks a-EAT cells from adhering to both laminin- and fibronectin-coated plates. An RGD-containing peptide (GRGDSP) inhibits the adhesion of a-EAT cells to fibronectin-coated but not to laminin-coated plates. Taken together, these data suggest that a-EAT cells interact with laminin and fibronectin via different beta 1 integrins. As determined by immunofluorescence flow cytometry assay, both a-EAT and na-EAT cells express similar amounts of surface antigen(s) recognized by the same anti-alpha 5 beta 1 integrin polyclonal antibody that blocks a-EAT cells from adhering to laminin and fibronectin. The alpha 5 and beta 1 subunits expressed on both types of EAT cells appear to have the same molecular weight when analyzed by immunoblotting. The same amount of 125I-labeled membrane protein was isolated from both types of EAT cells on immobilized laminin and fibronectin affinity columns. These data indicate that na-EAT cells express similar amounts of cell surface integrins, and these integrins, when isolated, react with laminin and fibronectin in the same manner as the integrins of a-EAT cells, even though na-EAT cells are unable to adhere to laminin and fibronectin. Previous work has shown that both types of EAT cells express Neu5Ac alpha 2,3 Gal-beta 1, 4 GlcNAc residues on their cell surface and that they both react with Maackia amurensis lectin which specifically recognizes this carbohydrate structure. Here we show that both types of EAT cells attach to M. amurensis lectin-coated surfaces, but only a-EAT cells spread; this suggests that the differences between these two types of cells in responding to extra cellular matrix molecules may reside in some differences within the cell.