Structural and morphological study of pulsed laser deposited calcium phosphate bioceramic coatings: influence of deposition conditions, laser parameters, and target properties

Calcium phosphate (CaP) bioceramics, especially hydroxyapatite (HA), have been used as coatings on implants owing to their biocompatible properties. The commercial practice for applying HA coating, plasma spraying, has some disadvantages which limit the long-term stability of the implants. Pulsed laser deposition (PLD) is being investigated as an alternative technique. The purpose of this research was to systematically study the effect of various parameters of the PLD process on the properties of CaP coatings. In this study, three types of HA targets and two laser wavelengths were used to make six categories of coatings. Predominantly crystalline HA coatings were produced under all six categories at optimum conditions, although small amounts of minor phases sometimes were found. Sufficient coating/substrate bond strength was also obtained. A wide variety of coating morphologies was obtained, from rather dense and uniform to rough and porous. The important factors that affected the morphology included target properties, vacuum level, deposition temperature, and laser wavelength and energy density. PLD's ability to produce both amorphous and crystalline, and both smooth/dense and rough/porous coatings may be a unique advantage.

Ability of the glucocorticoid modulatory element to modify glucocorticoid receptor transactivation indicates parallel pathways for the expression of glucocorticoid modulatory element and glucocorticoid response element activities

The glucocorticoid modulatory element (GME) of the rat tyrosine aminotransferase gene is located at -3.6 kb and 1 kb upstream of the glucocorticoid response elements (GREs). The GME has the unique transcriptional properties of modulating both the dose-response curve of agonists bound to the glucocorticoid receptor (GR) and the residual agonist activity of GR-bound antisteroids. The expression of GME activity involves the binding of two novel proteins (GMEB-1 and GMEB-2) that we have recently cloned. However, the mechanistic details are limited. The DNA sequence requirements for GME activity (CGTC) also remain poorly defined, which restricts efforts to identify other GME modulated genes. To help understand the mechanism for the unusual activities of the GME and to identify permissive gene environments for GME activity, we compared the changes in GME activity and GRE action (i.e. the fold induction by GR) caused by modifying several parameters. Phasing between the GME and downstream tandem GREs was unimportant, in contrast to other cis-acting elements like the GRE, while GME activity decreased rapidly when placed at increasingly larger distances 3' to a tandem GRE. A minimal promoter was less effective in supporting GME than GRE activity. Although CREB binds to the GME, overexpression of CREB reduced GRE, but not GME, activity and a CRE was inactive when substituted for the GME. No effect of the GME was observed on the binding of GRs to a single GRE. However, the GME upstream of a single GRE was also unable to produce a left shift in the Dex dose-response curve under conditions where the GME was active with two GREs. In the absence of any GREs, the GME displayed intrinsic activity by elevating basal level expression. Collectively, these results indicate that an optimal position for a functional GME is within 250 bp upstream of a tandem GRE driving a complex promoter. Furthermore, as the changes in GME activity did not correlate with those for fold induction from the GRE, the mechanisms for expression of GME and GRE activities appear to utilize parallel, as opposed to common pathways.

Genomic organization of human GMEB-1 and rat GMEB-2: structural conservation of two multifunctional proteins

The glucocorticoid modulatory element binding proteins 1 and 2 (GMEB-1 and GMEB-2) are of interest both for their multiple activities (e.g. modulation of transactivation by the glucocorticoid receptor and initiation of parvovirus replication) and their membership in the emerging family of KDWK proteins. The genomic sequence of these proteins was desired in order to begin studies on the control of GMEB expression and to pursue previous evidence for significant homologies between the GMEBs. We now report the genomic sequence of human GMEB-1 and rat GMEB-2. The structure of both genes, including portions of the introns, is highly conserved. However, GMEB-1 and GMEB-2 were found to reside on chromosomes 1 and 20, respectively, demonstrating that they are encoded by distinctly different genes. Several isoforms of the GMEBs have been reported or detected in this study, and the splicing patterns were determined. The tissue distribution of each GMEB is not the same and is highest in fetal and developing tissues, consistent with previous suggestions that both homo- and hetero-oligomers may possess biological activity. The promoter region of both genes has been identified and both display high levels of transcription activity in transiently transfected cells when fused upstream of a promoterless reporter. These results indicate that the GMEBs are proteins that evolved from a single parent gene, have been highly conserved since the divergence of rats and humans and probably play important roles in development and differentiation.

Effect of intravenous nitroglycerin on hemodynamics in infants and children with congestive heart failure

OBJECTIVE

To understand the effect of intravenous nitroglycerin (NTG) on hemodynamics in infants and small children with congestive heart failure secondary to congenital cardiac defect of left to right shunt.

METHODS

Heart rate, blood pressure and total peripheral resistance were monitored continuously. Echocardiography was used to measure ejection fraction, fractional shortening, end-diastolic volume index of left ventricle, pulmonary capillary wedge pressure, pulmonary artery mean pressure and left ventricular wall stress before the use and during 0.5, 1.0, 1.5, 2.5, and 5.0 micrograms.kg-1.min-1 dosages of nitroglycerin (NTG).

RESULTS

There was no significant difference in the indexes of heart rate, blood pressure, ejection fraction and fractional shortening of left ventricle, stroke volume index, cardiac output index, end-diastolic volume index before the use and after the use of NTG. Pulmonary capillary wedge pressure decreased from 15.5 +/- 2.3 mm Hg before the use of NTG to 14.3 +/- 2.2 mm Hg after the use of 0.5 microgram.kg-1.min-1 NTG (P < 0.05), minimum to 12.3 +/- 2.4 mm Hg; left ventricular wall stress I, II and III decreased from 407 +/- 65 dyn.cm-2.10(3), 166 +/- 48 dyn.cm-2.10(3), 255 +/- 52 dyn.cm-2.10(3) to 357 +/- 75 dyn.cm-2.10(3), 136 +/- 48 dyn.cm-2.10(3), 218 +/- 52 dyn.cm-2.10(3) (P < 0.05), minimum to 321 +/- 50 dyn.cm-2.10(3), 114 +/- 42 dyn.cm-2.10(3), 187 +/- 42 dyn.cm-2.10(3), respectively. Total peripheral resistance and pulmonary artery mean pressure were decreased when the dosage of intravenous NTG was increased to above 2.5 micrograms.kg-1.min-1 (P < 0.05). There was no statistical difference in the above indexes of the different dosages.

CONCLUSION

Congestive heart failure secondary to congenital cardiac defect of left to right shunt in infants and small children is the indication of using intravenous NTG which could improve hemodynamics. There was different selectivity in dosage between arterial and venous vasodilatation, and the change in hemodynamics was independent of dosage. The dosages of 0.5-1.0 microgram.kg-1.min-1 NTG are recommended when the decrease of cardiac preload is the main point of therapy of heart failure.

Expansion of genetically modified primary human hemopoietic cells using chemical inducers of dimerization

The inability to deliver a therapeutic gene to a sufficient percentage of hematopoietic stem cells is the major obstacle to using gene therapy to treat blood disorders. Providing genetically corrected stem cells with a reversible growth advantage could solve this problem. To this end we have employed small synthetic molecules that can reversibly dimerize and activate fusion proteins which contain a growth factor receptor signaling domain. We have shown that the thrombopoietin receptor (mpl) signaling domain can be used in this system to expand transduced multipotential progenitor cells from mouse bone marrow. In the present study we tested a similar retroviral vector in human CD34-selected cord blood cells. Following transduction, cells cultured in the presence of the dimerizing molecule AP1903 expanded 13.8- to 186-fold relative to cells cultured in the absence of AP1903. The cell type that emerged in suspension culture was erythroid. Contrary to our results in the murine system, cell expansion was transient. Activation of mpl caused the disappearance of BFU-E followed by a transient increase in CFU-E. In contrast, mpl activation had no discernable effect on transduced myeloid progenitor cells. AP1903-mediated expansion was restricted to transduced cells, as demonstrated by immunohistochemical staining. These findings indicate that synthetic dimerizing molecules can be used to expand primary human hematopoietic cells. (Blood. 2000;95:430-436)

XPS, EDX and FTIR analysis of pulsed laser deposited calcium phosphate bioceramic coatings: the effects of various process parameters

Many techniques have been used to produce calcium phosphate, especially hydroxyapatite (HA), coatings on metallic implant surfaces for improved biocompatibility. Although some techniques have produced coatings used clinically, the long-term stability of the coating/implant is still questionable. As a new technique for making HA coatings, pulsed laser deposition (PLD) shows some advantages in controlling the coatings' crystal structure and composition. In this study, three types of HA target and two wavelengths of laser were used to produce calcium phosphate coatings. Despite PLDs ability to improve the crystal structure by incorporating water vapor into the deposition process, the characterization with EDX and XPS showed that coatings had different Ca/P ratios from that of the pure HA targets, which almost assured the presence of non-HA phases. FTIR spectra also showed differences in phosphate bands of coatings and targets although the difference in data collecting modes might have been a factor. The observed differences might be related to the differences between the surface and bulk chemistries of the coatings. Nevertheless, when evaluating the suitability of the PLD technique for making HA coatings, the possibility of the formation of non-HA phases cannot be excluded, although it may not necessarily be a negative factor.

Direct plasma sample injection in multiple-component LC-MS-MS assays for high-throughput pharmacokinetic screening

The simultaneous dosing of numerous compounds followed by multiple-component analysis using LC-MS-MS (the N-in-1 approach) has significantly improved the throughput of the drug-screening process. However, plasma samples still need to be extracted before LC-MS-MS analysis, which frequently limits the throughput of the assay. In this work, a high-throughput on-line extraction technique has been developed for multiple-component LC-MS-MS assays using a high-flow column-switching technique. In N-in-1 LC-MS-MS assays, high sensitivity is required since the dose level is generally reduced to minimize drug-drug interactions. In addition, good chromatographic separation is essential to minimize interference and suppression effects. The direct plasma sample injection method developed in this work has successfully met the two requirements for multiple-component LC-MS-MS assays in high-throughput pharmacokinetic screening. Plasma samples containing a large number of potential drug candidates were directly injected onto an extraction column operated under a flow rate sufficiently high to exhibit a turbulent-flow profile. The extracted analytes were then eluted onto an analytical column via column switching for LC-MS-MS analysis. The use of turbulent flow resulted in a faster and more rugged extraction with reduced carryover compared with results obtained under laminar-flow conditions. Meanwhile, the use of a column-switching method maintained the chromatographic resolving power and high sensitivity of the LC-MS-MS assay. Separation efficiency, dynamic range, accuracy, and precision comparable with those of solid-phase extraction have been achieved with the turbulent-flow column-switching technique. As a result, this technique has been successfully and routinely used for high-throughput pharmacokinetic screening.

Cloning and expression of rat transforming growth factor beta 1 cDNA in osteoblasts

Rat transforming growth factor beta 1 (rTGF beta 1) cDNA from rat lymphocytes was cloned by RT-PCR and inserted into pcDNA3 to construct an eukaryotic expression vector, which was named pcDNA3-TGF beta 1. The cloned gene was confirmed to code rat TGF beta 1 by restriction enzyme analysis. pcDNA3-TGF beta 1 plasmid was transfected into rat osteoblasts by using liposome-mediated gene transfer technique and the expression of TGF beta 1 was detected by using immunohistochemical staining assay. It was found that the rat TGF beta 1 expression product was obviously detectable in the transfected osteoblasts in 48 h. High expression of TGF beta 1 was obtained in the rat osteoblasts in which the constructed TGF beta 1 expression vector was transfected.

Stimulation with carbachol alters endomembrane distribution and plasma membrane expression of intracellular proteins in lacrimal acinar cells

The events that lead to Sjögren's autoimmune processes in the lacrimal gland remain poorly understood. The acinar cell's responses to acute cholinergic stimulation include release of secretory products across the apical plasma membrane (apm) and a number of processes related to traffic between endomembrane compartments and the basal-lateral plasma membranes (blm), such as recruitment of Na, K-ATPase, accelerated recycling, and accelerated transcytosis of secretory IgA. We tested the hypothesis that stimulation-induced acceleration of endomembrane traffic is accompanied by changes in compartmentation and increased blm expression of proteins that are normally sequestered in endomembrane compartments. Isolated rabbit lacrimal gland acinar cells were cultured in serum-free media for 2 days. After harvesting, cells were incubated with or without 10 microm carbachol at 37 degrees C for 20 min. Cells were lysed, and lysates were analysed by isopycnic centrifugation on sorbitol gradients. Galactosyltransferase catalytic activity was determined biochemically. Different forms of cathepsin B were detected by Western blotting. Carbachol stimulation decreased the contents of beta-hexosaminidase, alpha-glucosidase, and protein in secretory vesicles and increased them in specific compartments of the trans-Golgi network (ld-tgns). Stimulation also caused levels of galactosyltransferase, preprocathepsin B, and procathepsin B to increase two- to three-fold in the blm as well as increasing in the ld-tgns. Other changes caused by sustained stimulation included: (a) increased levels of protein and procathepsin B in compartments of the lysosomal pathway; (b) changes in the distributions of Rab5 within the endomembrane system; (c) changes in the distribution of Rab6 within the Golgi complex and tgn; (d) decreased expression of acid phosphatase and MHC class II molecules in the blm; and (e) decreased total content of Na,K-ATPase, which appeared to have been selectively depleted from the tgn and blmre. We propose that the normal compartmentation of certain proteins may allow them to remain cryptic, such that they are not subject to central tolerance. Stimulation-induced increases in the levels expressed at the blm or secreted to the interstitium may, therefore, contribute to initiation of local autoimmune responses.

Expression of multidrug resistance protein-3 (multispecific organic anion transporter-D) in human embryonic kidney 293 cells confers resistance to anticancer agents

Multidrug resistance-associated protein (MRP)1 and canalicular multispecific organic anion transporter (cMOAT)/MRP2 are ATP-binding cassette (ABC) transporters that confer resistance to natural product cytotoxic drugs. We recently described the complete coding sequences of four human MRP/cMOAT subfamily members and found that, among these proteins, MRP3/MOAT-D is most closely related to MRP1 (58% identity; M. G. Belinsky and G. D. Kruh, Br. J. Cancer, 80: 1342-1349, 1999). In the present study, we sought to determine whether MRP3 is capable of conferring resistance to cytotoxic drugs. To address this question, human embryonic kidney 293 cells were transfected with an MRP3 expression vector, and the drug resistance phenotype of the transfected cells was analyzed. The MRP3-transfected cells displayed approximately 4-fold resistance to etoposide and approximately 2-fold resistance to vincristine, compared with control transfected cells. In addition, approximately 1.7-fold resistance was observed for the antimetabolite methotrexate. Increased resistance was not observed for several other natural product agents, including anthracyclines and Taxol. The MRP-transfected cells exhibited reduced accumulation of radiolabeled etoposide, consistent with the operation of a plasma membrane efflux pump. These results indicate that MRP3 confers resistance to some anticancer agents but that its resistance pattern is distinct from the resistance patterns of other ABC transporters involved in resistance to natural product chemotherapeutic agents.

A Supramolecular Tetra-Keggin Polyoxometalate

Giant polyoxometalates with catalytic, magnetic, and antiviral properties, which are in part attributable to their structures, are currently of great interest. Herein is described the synthesis and characterization of 1, a structurally novel tetrameric complex from Keggin ions (see picture). This complex is stable under the physiological conditions of the stomach (pH 1-2), which is interesting since related keggin anions are among the least toxic and yet most potent antiviral agents of the more than 300 polyoxometalates investigated biologically and pharmacologically.

MHC class II molecules, cathepsins, and La/SSB proteins in lacrimal acinar cell endomembranes

Sjögren's syndrome is a chronic autoimmune disease affecting the lacrimal glands and other epithelia. It has been suggested that acinar cells of the lacrimal glands provoke local autoimmune responses, leading to Sjögren's syndrome when they begin expressing major histocompatibility complex (MHC) class II molecules. We used isopycnic centrifugation and phase partitioning to resolve compartments that participate in traffic between the basolateral membranes and the endomembrane system to test the hypothesis that MHC class II molecules enter compartments that contain potential autoantigens, i.e., La/SSB, and enzymes capable of proteolytically processing autoantigen, i.e., cathepsins B and D. A series of compartments identified as secretory vesicle membranes, prelysosomes, and microdomains of the trans-Golgi network involved in traffic to the basolateral membrane, to the secretory vesicles, and to the prelysosomes were all prominent loci of MHC class II molecules, La/SSB, and cathepsins B and D. These observations support the thesis that lacrimal gland acinar cells that have been induced to express MHC class II molecules function as autoantigen processing and presenting cells.

Effects of quenched disorder on the orientational order of the octylcyanobiphenyl liquid crystal

Deuteron NMR (DNMR) measurements were performed with high-temperature and spectral resolution on the octylcyanobiphenyl (8CB) liquid crystal confined to the randomly interconnected pores of silica aerogel as a function of temperature and silica density. The aerogel density was varied by one order of magnitude and the temperature spanned the isotropic (I), nematic (N), and smectic-A (SmA) phases of 8CB. For all samples, the liquid crystal was confined to pores smaller than the micron-sized magnetic coherence length. Thus the observed line shapes reflect the director pattern, n(r-->), and the orientational order, Q, as dictated by the porous host. The DNMR spectral patterns are consistent with powder line shapes representative of a randomized n(r-->) characterized by a single Q. The nematic domains formed are of finite dimension that likely exceeds the confining size. The weakly first-order nematic-to-isotropic phase transition becomes less discontinuous with decreasing pore size, eventually becoming continuous at an aerogel density between 0.36 and 0.5 g/cm(3). In the most severe confinement, no phase transitions are observed with only a continuous evolution of Q present. The orientational order is suppressed from the bulk's with no enhancement upon the onset of the SmA phase. This indicates a decoupling of nematic and smectic order parameters and a severe suppression of the SmA phase by this porous media.

New method for detection of heart allograft rejection: validation of sensitivity and reliability in a rat heterotopic allograft model

BACKGROUND

Patients with inflammatory heart muscle diseases would benefit from a safe, convenient, rapidly performed diagnostic technique with real-time results not involving tissue removal. We have performed a detailed evaluation of detection of heart allograft rejection by autofluorescence in a heterotopic abdominal rat heart allograft model ex vivo.

METHODS AND RESULTS

Recipient rats with allograft (Lewis to Fisher 344; n=71) and isograft (Lewis to Lewis; n=33) hearts, treated with cyclosporine or untreated, were killed at days 2, 4, 7, 14, 21, 28, and 56 after transplant. Nontransplant controls with (n=24) or without (n=24) immunosuppressive therapy were also studied. When the rats were killed, autofluorescence spectra were acquired under blue-light excitation from midtransverse ventricular sections of native and transplanted hearts. Corresponding sections were then evaluated pathologically by a modified International Society for Heart and Lung Transplantation (ISHLT) grading schema. The spectral differences between rejecting and nonrejecting hearts were quantified by linear discriminant functions, producing scores that decreased progressively with increasing severity of tissue rejection. Mean+/-SD discriminant function scores were 2.9+/-1.6, 1.8+/-2.2, -0.1+/-2.8, -1.2+/-2.3, and -2.3+/-3.0 for isografts and allograft ISHLT grades 0, I, II, and III, respectively (Spearman rank-order correlation -0.6; P<0.001, test for trend). Cyclosporine had no detectable effect on the spectra.

CONCLUSIONS

The correlation between changes in autofluorescence spectra and ISHLT rejection grade strongly supports the possibility of catheter-based, fluorescence-guided surveillance of rejection.

[Influence factors in hepatic artery infusion chemotherapy and embolization of liver metastases from alimentary tract cancer]

OBJECTIVE

To evaluate the efficacy and the value of hepatic artery infusion chemotherapy and embolization in the treatment of liver metastases from alimentary tract cancer with Cox's proportional hazard model.

METHODS

A total of 92 patients with unresectable liver metastases from alimentary tract cancer were treated by hepatic artery infusion chemotherapy and embolization in 316 times. Of 92 patients, 29 were given infusion chemotherapy only, 63 were given infusion chemotherapy together with embolization. Anticancer agents were the combination of epirubicin and/or cisplatin, mitomycin-C and fiuorouracil plus calcium folinate, added to embolization with lipiodol ultrafluid or lipiodol ultra-fluid and gelatin sponge. Cox's proportional hazard model was used in multivariate analysis.

RESULTS

The results showed that the therapeutic efficacy of 9 cases with single liver metastasis was the best. The mean survival period > 30 months (P < 0.05). Comprehensive treatment significantly improves therapeutic efficacy (P < 0.01). Response rates were assessed by CT scan. An overall response rate (CR + PR) of the cases was 45.65%. The mean survival period of 92 patients were 19.6 months. The 0.5, 1, 2, 3, and 5-year survival rates were 95.7%, 73.8%, 36.3%, 20.6% and 11.6% respectively. These was no severe side effect or complication.

CONCLUSION

The hepatic artery infusion chemotherapy and embolization were of benefit to patients with liver metastases from alimentary tract cancer. It contributes not only to improving therapeutic efficacy, but also to an improved quality of life for the patients. Single liver metastasis and comprehensive treatment were the most important influence factors in hepatic artery infusion chemotherapy and embolization of the liver metasetases from alimentary tract cancer.

Molecular cloning of the Pasteurella haemolytica pomA gene and identification of bovine antibodies against PomA surface domains

The gene (pomA) encoding PomA, an OmpA-like major outer membrane protein of the bovine respiratory pathogen Pasteurella haemolytica, was cloned, and its nucleotide sequence was determined. The deduced amino acid sequence of PomA has significant identity with the sequences of other OmpA family proteins. Absorption of three different bovine immune sera with whole P. haemolytica cells resulted in a reduction of bovine immunoglobulin G reactivity with recombinant PomA in Western immunoblots, suggesting the presence of antibodies against PomA surface domains.

Evaluation of cardiac beta-adrenergic receptor function in children by dobutamine stress echocardiography

OBJECTIVE

To investigate the role of dobutamine stress echocardiography in evaluating cardiac beta-adrenergic receptor (beta-AR) function and responsiveness in children.

METHODS

Left ventricular ejection fraction (EF), fractional shortening (FS), left ventricular end systolic volume index (ESVI), the ratio of systolic blood pressure and ESVI (SP/ESVI) were measured by dobutamine stress echocardiography (DSE) in 30 children with beta-AR hypersensitivity, 15 children with dilated cardiomyopathy and 30 normal children respectively.

RESULTS

Before pharmacological stress, EF and FS were 0.72 and 0.39 respectively in beta-AR hypersensitivity group versus 0.70 and 0.35 respectively in control group. There was no difference of the indices between the two groups (P > 0.05). SP/ESVI was 0.76, higher than the value of 0.66 in control group (P < 0.05); EF, FS and SP/ESVI were 0.41, 0.15 and 0.10 respectively, which were significantly lower than those in control group. After dobutamine stress of 5 micrograms.kg-1.min-1 and 10 micrograms.kg-1.min-1, EF, FS and SP/ESVI were significantly increased in patients with beta-AR hypersensitivity and there were no changes in children with dilated cardiomyopathy compared with values of baseline.

CONCLUSION

Cardiac beta-AR function and responsiveness can be evaluated by dobutamine stress echocardiography.

[To evaluate the examinations both colour Doppler flow image and CT for orbital pseudotumors]

PURPOSE

To explore the values of colour doppler flow image(CDFI) technique and computer tomographic(CT) scan in diagnosising orbital pseudotumors.

METHODS

CDFI and CT were used for examining 67 cases of orbital pseudotumors demonstrated with surgery and pathaology. The results were treated with self-match design Chi-square test.

RESULTS

The diagnosis validities for 29 mass-type cases with CDFI and CT were 44.8% and 82.8%, respectively, with significant difference (chi 2 = 5.88, P < 0.05). The validities for 25 diffuse-type cases were 84.0% and 56.0%, respectively, with significant difference. (chi 2 = 4.0, P < 0.05). The validities for 19 mixture-type cases were 63.2% and 78.9%, respectively, with no significant difference (chi 2 = 1.63, P > 0.05). The diagnosis validities for all 67 cases were 63.0% and 72.7%, respectively, with no significant difference (chi 2 = 1.16, P > 0.05).

CONCLUSION

The diagnosis validities with both imaging methods were not different for diagnosis of orbital pseudotumors. But the values for diagnosing various pseudotumors were different. The validity with CDFI was superior to CT in diffuse type; CT was superior to CDFI in mass type; while the validity with CDFI and CT were not significant different in mixture type.

Enrichment of transiently transfected mesangial cells by cell sorting after cotransfection with GFP

Early passage mesangial cells, like many other nonimmortalized cultured cells, can be difficult to transfect. We devised a simple method to improve the efficiency of transient protein expression under the transcriptional control of promoters in conventional plasmid vectors in rat mesangial cells. We used a vector encoding modified green fluorescent protein (GFP) and sterile fluorescence-activated cell sorting (FACS) to select a population consisting of >90% GFP-expressing cells from passaged nonimmortalized cultures transfected at much lower efficiency. Only 10% transfection efficiency was noted with a beta-galactosidase expression vector alone, but cotransfection with GFP followed by FACS and replating of GFP+ cells yielded greater than fivefold enrichment of cells with detectable beta-galactosidase activity. To demonstrate the expression of a properly oriented and processed membrane protein, we cotransfected GFP with a natriuretic peptide clearance receptor (NPR-C) expression vector. Plasmid-dependent cell surface NPR-C density was enhanced by 89% after FACS, though expression remained lower in selected mesangial cells than in the CHO cell line transfected with the same vector. We conclude that cotransfection of rat mesangial cells with GFP, followed by FACS, results in improvement in transient transfection efficiencies to levels that should suffice for many applications.

Dissolution/reprecipitation of calcium phosphate thin films produced by ion beam sputter deposition technique

The dissolution, reprecipitation and protein adsorption properties of amorphous CaP bioceramic thin films produced with an ion beam sputter deposition technique using hydroxyapatite (HA) and fluorapatite (FA) as starting materials were studied using Fourier transform infrared spectroscopy (FTIR) with attenuated total internal reflectance (ATR). Our studies showed that these amorphous CaP coatings dissolved to a greater extent when exposed to bovine serum albumin (BSA) in saline solution when compared to a protein free saline solution. Analysis of changes in infrared spectra revealed that coatings exposed to BSA solution exhibited a higher degree of crystalline structure after dissolution/reprecipitation than those exposed to saline alone. There was the indication that the association of inorganic and organic contents was achieved on the coating surface in BSA solution. We could detect no significant difference between the coatings produced from HA and FA targets.

[Taxonomy of the producing strain of agricultural antibiotic 2-16]

In screening process of new agricultural, a streptomycetes, 2-16, was isolated from the soil sample collected in Huangsan. The secondary metabolites produced by the strain had strong inhibition to Sclerotinia sclerotiorum. By identification, this strain was regarded as new variety of Streptomyces ahygroscopicus and was called Streptomyces ahygroscopicus var. huangsanensis.

Analysis of bovine serum albumin adsorption on calcium phosphate and titanium surfaces

The protein adsorption behavior of thin films of calcium phosphate (CaP) bioceramic and titanium (Ti) was studied in this research. The thin films were produced with an ion beam sputter deposition technique using targets of hydroxyapatite (HA), fluorapatite (FA) and titanium (Ti). Fourier transform infrared spectroscopy (FTIR) with attenuated total internal reflectance (ATR) was used to evaluate protein adsorption on these surfaces. This study showed that surface composition and structure influenced the kinetics of protein adsorption and the structure of adsorbed protein. CaP surfaces adsorbed greater amount of protein than the Ti surface, and caused more alteration of the structure of adsorbed BSA than did the Ti surface. The differences in protein adsorption behavior could result in very different initial cellular behavior on CaP and Ti implant surfaces.

The experimental study on mixed culture of osteoblasts and tricalcium phosphate ceramics in vitro

To study the effects of tricalcium phosphate (TCP) ceramics on osteoblasts, the rat osteoblasts were cultured with the TCP ceramics in vitro. Scanning electron microscopy and the colorimetric methyl-thiazol-tetrazolium assay showed that the osteoblasts could adhere well to the surface of the ceramics and the culture dish, and the proliferation of the cells was not inhibited. The results demonstrated that TCP ceramics possessed an excellent cytocompatibility with the osteoblasts, and had some promoting effects on proliferation of osteoblasts.

[Study on the expression of interleukin-8 and its receptors in acute leukemia]

OBJECTIVE

To evaluate the expression of interleukin 8 (IL-8) and its A, B type receptors (IL-8RA, IL-8RB) in acute leukemia (AL).

METHODS

Plasma IL-8 concentrations in peripheral blood and IL-8R expressions on bone marrow mononuclear cell (MNC) membrane of 77 newly diagnosed AL patients were assayed by ELISA and FACS, respectively. IL-8 concentration in cerebral spinal fluid (CSF) of 15 AL patients in complete remission (CR) were kinetically measured.

RESULTS

Plasma IL-8 levels in newly diagnosed AL patients were increased. IL-8 levels were higher in AML than in ALL, in AML-M4, M5 were higher than in AML-M1-M3, and in B-ALL were higher than in T-ALL, respectively (P < 0.05). In ALL, CR rate in patients with IL-8 > 100 ng/L was lower than in those with IL-8 < or = 100 ng/L (P < 0.05). 36.36% of the patients were MNC IL-8R positive. Peripheral blood WBC and blasts amounts in IL-8R(+) group were significantly higher than IL-8R (-) group (P < 0.05). CSF IL-8 levels in CR patients were not different from newly diagnosed patients (P > 0.05) and were increased while central nervous system leukemia (CNSL) developed.

CONCLUSION

Detection of IL-8 and IL-8R might help to identify AL types and predict prognosis and the development of CNSL.

TCR diversity in gammadeltaTCR+ hybridomas derived from mice given portal vein donor-specific pre-immunization and skin allografts

Portal venous (p.v.) immunization with multiple minor histoincompatible cells leads to antigen-specific increased skin allograft survival. GammadeltaTCR+ hybridoma cells, prepared from mesenteric lymphocytes of p.v. immunized animals, can adoptively transfer this increased graft survival to naive animals. We have analyzed VgammaVdelta gene usage, and TCR gamma-chain junctional diversity in gammadeltaTCR+ hybridomas from mice immunized with different antigen combinations by p.v. or conventional lateral tail vein (i.v.) immunization. Following p.v. immunization two independent sets of hybridoma cells were derived, one expressing a common gamma-chain junctional sequence which was also found in > 85% of the hybridomas derived following i.v. immunization, while the other set showed remarkable gamma-chain junctional sequence diversity. The diversity seen in these latter hybridomas was associated with the antigen specificity of the hybridoma cells. Cells expressing these 'unique' TCR junctional sequences were stimulated to produce cytokines both by hsp and by minor-histocompatibility-specific irradiated peritoneal cells. Cells expressing TCR with a common gamma-chain junctional sequence were stimulated to cytokine production by MHC-matched but minor-histocompatibility mismatched (as well as matched) peritoneal cells, but not by hsp. We suggest that p.v. immunization results in stimulation of both antigen-specific and non-specific regulatory gammadeltaTCR+ cells, which can be distinguished by gamma-chain TCR sequence diversity.

[Development of a long-term dynamic ECG monitoring system (Holter system)]

The development of a Holter system is introduced here with the emphasis on some key problems such as low power consumption hardware design, high efficient real-time algorithm, high speed reliable playback interface and full function interactive software.

[The diagnosis and treatment of primary carcinoma of the duodenum]

OBJECTIVE

To improve the diagnosis and treatment of primary duodenal carcinoma.

METHOD

The records of 18 patients with primary carcinoma of the duodenum were reviewed.

RESULT

7 cases underwent pancreatoduodenectomy: segmental duodenectomy (1), intraoperative death (1), survived 3 years (2), and survived 5 years after operation (3). 7 cases underwent gastroenterostomy or cholangioenterostomy; they died in 11 months after operation. Three cases who received biopsy only died in six months after operation.

CONCLUSION

The understanding of duodenal carcinoma is the key factor for early diagnosis. The appropriate examinations are necessary for suspected patients. Once the diagnosis is confirmed, the result of surgical treatment is improved.

[Effect of allicin on ethanol-induced hepatotoxicity in mice]

To study the effect of allicin, an effective component of garlic, on ethanol-induced hepatotoxicity in mice. The results showed that allicin (10 mg/kg ig, qd x 10) could reverse the higher activities of serum ALT and glutathione s-transferase (GST) in ethanol-treated mice. Furthermore, allicin could significantly enhance the content of hepatic reduced glutathione (GSH), and the activities of hepatic glutathione peroxidase (GSH-Px), glutathione reductase (GSH-Re) and GST in ethanol-induced hepatotoxicity mice. There were no remarkable changes in the hepatic catalase (Cat) and superoxide dismutase(SOD) activities. These results suggested that allicin have the effective hepato-protection on ethanol-induced hepatotoxicity, which is related to its selective effect on the glutathione-related enzyme system.

Molecular cloning of a chitinase gene from Bacillus circulans C-2

The 2-10 kb DNA fragments of the PstI partially digested total DNA of Bacillus circulans C-2 were cloned into the PstI site of vector pUC19 and the resulting hybrid DNA molecules were then transformed into Escherichia coli. One chitinase gene-containing clone (named pCHT1) was selected from about 8000 recombinants on chitin overlay plates. Analysis of pCHT1 cut with 12 restriction enzymes showed that the inserted fragment in this clone was about 3.0 kb in size and contained one site for each of the three restriction enzymes: KpnI, SacI, and SspI. Cells harboring the recombinants plasmid (pCHT1-R) in which the insert was in an inverted orientation also displayed chitinase activity, indicating that the cloned fragment from B. circulans C-2 contained an intact chitinase gene and its own promoter could be recognized by the Escherichia coli transcriptional system. Southern hybridization analysis proved that the inserted fragment of pCHT1 was really from the genome of B. circulans C-2, and there was only one copy existing in the genome. This fragment could not hybridize with the total DNAs from the other seven chitinase-producing bacteria.

[Isolation and identification of Rhodopseudomonas acidophila from Fujian province, China]

A strain P301 of Gram negative purple nonsulfur bacterium was isolated from the ditch's mud collected in Fuzhou, Fujian. The cells are rod-shaped. Multiplication occur by budding without stalk formation. Growth optimum pH is 5.0-5.7. No growth factors required. The cells contain bacteriochlorophyll a. The photosynthetic membrane system consists of parallel lamellae. According to Bergery's Manual of Determinative Bacteriology, 8th ed. (1974) and 9th ed. (1994), the strain was identified to be Rhodopseudomonas acidophila. But on the side of enzyme activity, utilization of organic substrates and others the strain some differ from the type strain described by N Pfennig (1969). Therefore the strain P301 was identified to be Rhodopseudomonas acidophila var. fujianensis n. var.

Psoriatic plaques exhibit red autofluorescence that is due to protoporphyrin IX

In evaluating the autofluorescence properties of normal and diseased skin we discovered that psoriatic plaques can emit a distinct red fluorescence when illuminated with UVA or blue light. Using a macrospectrofluorometer equipped with a 442 nm excitation laser, a sharp in vivo fluorescence emission peak around 635 nm could be demonstrated within the plaques of 34 of 75 (45%) patients with psoriasis. This peak was absent from normal appearing skin of psoriatic patients and also from the skin of 66 patients with other dermatologic diseases. A microspectrofluorometer coupled with the same excitation laser was used to obtain emission spectra of separated epidermal sheets and dermis from plaques demonstrating macroscopic red autofluorescence. An emission peak around 635 nm was observed in all three patients thus studied, but only on spectra obtained from the epidermis. Additional spectra of vertical microscopic sections of intact psoriatic skin from five other patients revealed that the peak originated from the stratum corneum. Emission spectra from other microlocations including the mid-epidermis and dermis of psoriatic and normal skin, as well as the stratum corneum of normal skin, failed to demonstrate a 635 nm peak. The excitation and emission fluorescence spectra of acid extracts of psoriatic scale from five patients were all similar to those of protoporphyrin IX in acid solution. High performance liquid chromatography identified the presence of protoporphyrin IX in the acid extracts from psoriatic scale of the same patients. We conclude that native psoriatic plaques can exhibit red autofluorescence that is due to elevated levels of protoporphyrin IX within scales.

[Expression and significance of interleukin 6, interleukin 8 and their receptors in acute promyelocytic leukemia during all-trans retinoic acid induction treatment]

OBJECTIVE

To evaluate the expression and clinical significance of interleukin 6, soluble glycoprotein 130 (sgp 130), interleukin 8 and type A interleukin 8 receptor (IL-8RA) in acute promyelocytic leukemia (APL) patients during all-trans retinoic acid (ATRA) treatment.

METHODS

Serum and bone marrow mononuclear cell (MNC) culture supernatant IL-6, sgp 130, IL-8 concentrations of 18 cases APL patients were measured (ELISA). Bone marrow MNC IL-8RA was measured by flow cytometry after cultured with ATRA (10(-6) mmol/L).

RESULTS

Serum IL-6, sgp130, IL-8 levels were higher than normal (P < 0.05), IL-6, sgp130 levels correlated with white blood cell (WBC) counts (P < 0.05) while IL-8 level correlated with body temperature (P < 0.05) at initial diagnosis after 72-hour incubation with ATRA, concentration of IL-6 of bone marrow MNC culture supenatant did not change, that of sgp130 mildly decreased, and IL-8 significantly decreased while the positive rate of IL-8RA on bone marrow MNC increased. During ATRA treatment, serum IL-6 changes were correlated with WBC changes. Peak level of IL-6 and WBC was lower in patients received intermittent therapy than continuous therapy. Serum IL-6 and IL-8 increased when complicated with infection and increase in IL-8 seemed more sensitive.

CONCLUSION

Serum levels of IL-6, sgp130, IL-8 may reflect patient's responsiveness to ATRA treatment, predict hyperleukocytosis and intercurrent infection. ATRA induces APL cell differentiation possibly via gp130 signal transduction.

A role for persisting antigen, antigen presentation, and ICAM-1 in increased renal graft survival after oral or portal vein donor-specific immunization

BACKGROUND

We studied the mechanism behind increased renal allotransplant survival when C3H mice received donor-specific portal vein or oral immunization with C57BL/6 cells. Both regimens lead to donor-specific increased graft survival, in association with decreased production of cytotoxic T lymphocytes and altered cytokine production from host lymphocytes (decreased interleukin [IL]-2 production; increased IL-4, IL-10, and transforming growth factor-beta).

METHODS

We examined a role for persistent donor-derived antigen, in association with host dendritic cells, as well as a role for intercellular adhesion molecule-1 (ICAM-1), in the maintenance of unresponsiveness in host C3H spleen cells to donor antigen. We investigated whether there was a cooperative interaction between donor dendritic cells (DC) and host hepatic mononuclear cells in the induction of immunoregulation in C3H cells.

RESULTS

In mice with surviving renal grafts, donor antigen, in association with host DC, induced the recall of cytotoxicity from C57BL/6 immune C3H spleen cells and IL-4 but not IL-2 production, despite the decreased cytotoxicity seen in the renal transplant recipients themselves. Fresh donor DC induced IL-2 but not IL-4 production. Blocking expression of ICAM-1 on donor grafts, either with anti-ICAM-1 monoclonal antibodies after renal grafting or using grafts from ICAM-1 "knockout" mice, led to further increased survival. Cultured C3H responder spleen cells, incubated with C57BL/6 DC and C3H hepatic cells, transferred hyporesponsiveness to C57BL/6 cells in vitro and in vivo (as assayed by survival of C57BL/6 renal allografts).

CONCLUSIONS

Our data suggest a role for ICAM-1, persistent donor antigen (on host DC), and accessory hepatic monocytes in the induction and maintenance of tolerance after portal vein immunization.

The dynamics of laser-induced changes in human skin autofluorescence--experimental measurements and theoretical modeling

To study the temporal dynamics of human skin autofluorescence photobleaching, we measured the autofluorescence spectral changes of skin in vivo during continuous exposure to 442 nm (He-Cd) laser light. Integral intensities were calculated for various spectral wavelength bands and plotted as a function of time. Mathematical analysis of the time function revealed a double-exponential photobleaching process: I(t) = a exp (-t/tau 1) + b exp(-t/tau 2) + c, in which tau 1 and tau 2 differed by an order of magnitude. A hypothesis for the mechanism of the double-exponential photobleaching dynamics was proposed and evaluated using Monte Carlo modeling of light propagation in the skin and autofluorescence escape from skin. By combining the fluorophore microdistributions, Monte Carlo simulation results and the variation in fluorescence decrease parameters (a, b, c, tau 1, tau 2) with increasing exposure intensities a biophysical explanation for the double-exponential photobleaching function was elucidated. The fast decrease term corresponds to laser-induced photobleaching in the stratum corneum, while the slow decrease term represents fluorophore changes in the dermis. The measured autofluorescence photobleaching dynamics can be used to determine the fractional contributions of different skin layers to the total autofluorescence signal measured in vivo.

Cloning and characterization of a novel binding factor (GMEB-2) of the glucocorticoid modulatory element

The 21-base pair glucocorticoid modulatory element (GME) of the rat tyrosine aminotransferase gene is the only cis-acting element known to modulate the transcriptional activity of receptors bound to glucocorticoid response elements. Specifically, the GME increases the activity of complexes bound both by physiological concentrations of glucocorticoids, due to a left shift in the dose-response curve, and by saturating concentrations of anti-glucocorticoids. For this reason, the nuclear protein(s) that has been demonstrated to bind to the GME is of major interest as a possible transcription factor with hitherto undescribed properties. Subsequent studies indicated that not one but two proteins of 88 and 67 kDa (= GMEB-1 and -2, respectively) formed a heteromeric complex with double-stranded GME oligonucleotides in gel shift assays and participated in the expression of GME activity (Oshima, H., Szapary, D., and Simons, S. S., Jr. (1995) J. Biol. Chem. 270, 21893-21910). Here, we report the use of polymerase chain reaction of degenerate oligonucleotides and 5'- and 3'-rapid amplification of cDNA ends to clone two cDNAs of 2. 0 and 1.9 kilobase pairs that probably result from alternative splicing. Both cDNAs encoded open reading frames containing all four previously sequenced peptides. The longer 2.0-kilobase pair cDNA encoded an open reading frame for an acidic, 529-amino acid protein and afforded a major 67-kDa and a minor 58-kDa protein after in vitro transcription/translation. Both proteins were recognized by a mono-epitopic antibody raised against a peptide of GMEB-2. The in vitro translated protein bound to GME DNA in gel shift assays. However, the binding to GME DNA increased markedly after mixing with authentic GMEB-1 to give a gel-shifted complex that was similar to that derived from HTC cell cytosol. GMEB-2 shares a unique domain (KDWKR) with proteins derived from diverse organisms as follows: Drosophila (DEAF-I), rat (Suppressin), and Caenorhabditis elegans (three unknown open reading frames). Collectively, these data suggest that the 67-kDa GMEB-2 not only is an important factor for the modulation of glucocorticoid receptor bound to glucocorticoid response elements but also may belong to a novel family of transcription factors.

Low ubiquinone content in Escherichia coli causes thiol hypersensitivity

Thiol hypersensitivity in a mutant of Escherichia coli (IS16) was reversed by complementation with a plasmid that carried the ubiX gene. The mutant had low ubiquinone content. Complementation elevated the ubiquinone level and eliminated thiol hypersensitivity. Analysis of chromosomal ubiX genes indicated that both parent and mutant strains were ubiX mutants. The low ubiquinone content of IS16 was possibly caused by a ubiD ubiX genotype. A ubiA mutant also exhibited thiol hypersensitivity. Neither IS16 nor the ubiA mutant strain could produce alkaline phosphatase (in contrast to their parent strains) after 2 h of induction, thus showing Dsb- phenotypes. The phenomena of thiol hypersensitivity and low ubiquinone content may be linked by their connections to the periplasmic disulfide bond redox machinery.

[Expression of interleukin-8 and its receptor in acute promyelocytic leukemia under all-trans retinoic acid treatment]

OBJECTIVE

To evaluate the clinical significance of expression of interleukin-(IL-8) and its type A receptor(IL-8RA) in acute promyelocytic leukemia(APL) patients under all trans-retinoic acid(ATRA) induction.

METHODS

Serum IL-8 level of 18 APL patients were dynamically studied(ELISA). Fresh APL cells from 3 patients were cultured with ATRA(10(-6) mmol/L). Supernatant IL-8 level and IL-8RA expression on APL cells were measured by FACS.

RESULTS

In vitro, IL-8 concentrations decreased 72 hours after incubation, while IL-8RA increased. In vivo, IL-8 increased more rapidly and markedly than temperature and WBC counts did before retinoic acid syndrome(RA-S) occurred. Serum IL-6 and IL-8 levels significantly increased when the patients suffered infection, and IL-8 increased even before fever. Both IL-8 and D-dimer increased while DIC progressed.

CONCLUSION

ATRA inhibited IL-8 secretion of APL cells while increased the expression of IL-8RA. Monitoring serum IL-8 concentrations could predict the development of RA-S and infection. Increase of both IL-8 and D-dimer concentrations suggested DIC progression.

Synergetic protective effects of combined blockade by two kinds of autolesion mediator receptor on neurological function after cervical cord injury

OBJECTIVE

To investigate the effects of combined blockade by platelet activating factor (PAF) receptor antagonist BN52021 in combination with opiate receptor antagonist naloxone on neurological function and neurological tissue damage after cervical cord injury.

METHODS

Spinal cord contusion at C6 segment was made with Allen method in cats, which were randomly divided into four groups: saline control group; BN52021 group; naloxone group; and combined treatment group with BN52021 and naloxone. Alteration of cervical cord blood flow, blood barrier permeability of the spinal cord, cervical cord tissue pathology and neurological functional scores were studied after experimental cervical cord injury.

RESULTS

The animals treated with BN52021 or naloxone had significantly better functional scores than saline controls 6 weeks after injury (P < 0.05). Moreover, the combined treatment showed significantly better neurologic recovery than either naloxone or BN52021 treated animals (P < 0.05). The other indexes in combined treatment animals were also superior to those in naloxone or BN52021 treated animals.

CONCLUSIONS

Combined blockade by two kinds of autolesion mediator receptor can more effectively inhibit secondary damage production and development after cervical cord injury and improve neurologic function.

[Retinoic acid inducing Fas expression in HL-60 cells]

OBJECTIVE

To investigate the effect of all-trans retinoic acid (ATRA) and 9-cis retinoic acid (9-cis RA) on the expression of Fas and the sensitivity to anti-Fas induced apoptosis in HL-60 cells.

METHODS

Fas expression was detected by flow cytometry. Anti-Fas induced apoptosis (AFIA) was determined by morphological features, DNA fragment electrophoresis, and flow cytometric cell cycle analysis.

RESULTS

Fas antigen was weakly expressed on HL-60 cells. After incubation of HL-60 cells with 10(-6) mol/L ATRA or 9-cis RA for 4 days, both the Fas expression and AFIA were significantly enhanced. 9-cis RA was more potent than ATRA in increasing the sensitivity to AFIA.

CONCLUSION

RA might upregulate Fas expression. Further elucidation of its molecular mechanisms might provide a rationale for new therapeutic strategies of malignant diseases.

Increased expression of the novel molecule OX-2 is involved in prolongation of murine renal allograft survival

BACKGROUND

Portal venous (p.v.) peritransplant immunization with dendritic cells from bone marrow cultures, along with cyclosporine (10 mg/kg), produces antigen-specific increased renal allograft survival compared with recipients receiving intravenous (i.v.) immunization. Increased survival is associated with altered cytokine production from recipient T cells restimulated with donor antigen. We used a suppressive subtractive hybridization approach to explore a role in the regulation of transplant rejection for other genes differentially expressed after p.v. immunization.

METHODS

Subtractive hybridization was performed using tissue from p.v. and i.v. immunized mice and a novel polymerase chain reaction-based approach. A gene-bank search was used to identify the source of the differentially expressed cDNAs. One product, the mouse homologue of rat OX-2, was further analyzed using Western gels and FACS analysis of dendritic cells (NLDC145+) isolated from p.v.-immunized mice.

RESULTS

Eighty cDNA clones were obtained by suppressive subtractive hybridization. Differential expression was confirmed in Northern RNA blots. One clone showed sequence homology to a gene encoding a molecule on rat dendritic cells (MRC OX-2), with homology to genes encoding the costimulatory molecules CD80 (B7-1) and CD86 (B7-2). In p.v.-immunized mice, a monoclonal antibody to the rat OX-2 molecule identified, by Western blot analysis, increased expression of a molecule with molecular weight (43 kDa) analogous to rat MRC-OX-2; labels (by FACS analysis) indentified increased numbers of a population of cells staining with NLDC145; and blocks indentified increased graft survival.

CONCLUSION

Our data suggest that OX-2 is functionally important in the increased graft survival seen in p.v.-immunized mice receiving renal allografts.

Analysis of cytokine production and V beta T-cell receptor subsets in irradiated recipients receiving portal or peripheral venous reconstitution with allogeneic bone marrow cells, with or without additional anti-cytokine monoclonal antibodies

Irradiated (800 rads) AKR mice received intravenous (i.v.) reconstitution with a mixture of B10.BR T-depleted bone marrow cells and spleen cells. Only in groups of mice treated additionally with i.v. cyclophosphamide (Cy; 150 mg/kg), 24 hr before transplantation, was long-term (> 60% at 50 days) survival seen. In mice receiving only irradiation all animals died by 30 days post-transplantation. Histological changes consistent with graft-versus-host disease (GVHD) were seen in the liver of reconstituted mice at 30 days, along with an organ-specific increase in V beta 3 T-cell receptor-positive (TCR+) cells. No such increase in V beta 3 TCR+ cells was seen in the spleen from the same mice. These data are consistent with a tissue antigen-driven expansion of V beta 3 TCR+ cells associated with GVHD in the liver in this model. When we analysed cytokine production in vitro from CD3+ cells restimulated with 'host' (AKR) antigen-presenting cells (APC), we found a transition in cytokine production from preferential synthesis of type-1 cytokines [interleukin-2 (IL-2) and interferon-gamma (IFN-gamma)] at early times (day 15) post-reconstitution to increased production of type-2 cytokines [IL-4, transforming growth factor-beta (TGF-beta) and IL-10] at later times (day 30) post-reconstitution in Cy-treated recipients. Animals not receiving Cy did not show this 'switch' in cytokine production at later time points. We have observed a similar polarization in cytokine production, along with increased graft survival, in recipients of vascularized and non-vascularized allografts after portal venous (p.v.), but not i.v., pretransplant donor-specific immunization. We next studied AKR mice receiving 800 rads and subsequently reconstituted with B10.BR stem cells via the p.v. route. Again these mice showed prolonged survival (> 50% at 50 days), with polarization to IL-4, IL-10 and TGF-beta on restimulation of CD3+ cells in vitro at 30 days post-transplant and increased V beta 3 TCR+ cells in the liver. Infusion of anti-IL-12 monoclonal antibodies into irradiated mice receiving i.v. cell reconstitution produced a similar pattern of changes to those seen after p.v. reconstitution, while a combination of anti-IL-10 and anti-TGF-beta monoclonal antibodies reversed the changes seen after p.v. reconstitution. These data are consistent with an important role for differential cytokine production in the regulation of GVHD following allogeneic bone marrow transplantation.

Biodegradation of tricalcium phosphate ceramics by osteoclasts

Biodegradation of tricalcium phosphate (TCP) ceramics was observed through mixed culture of osteoclasts and TCP discs in vitro in this study. Osteoclasts were isolated from newborn SD rat's marrow of long bone and cultured on TCP discs. The culture terminated at the 48th h and 96th h respectively. Under an inverted microscope, the osteoclasts imparted round or oval body with multinuclear and many thin processes. These cells were positively stained for tartrate-resistance acid phosphatase (TRAP). Scanning electron microscope showed that many resorption lacunae on TCP disc surface and their diameters were smaller than 20 microns. Osteoclasts were located in the lacunae. At the 96th h, the resorption lacunae become larger and osteoclasts showed degeneration. It is suggested that osteoclasts possess ability to re-absorb TCP ceramics under in vitro culturing condition.

[Design of the ECG recording system based on ISD2500 series voice chips]

An ECG recording system based on voice chip ISD2560 is introduced. According to the frequency range of ECG, we make the best use of the ISD2500 series voice chips. This device can easily record patient's ECG for clinical diagnosis.

Cloning and characterization of the murine homologue of the rat/human MRC OX-2 gene

A 350 bp amplicon, obtained by PCR-select subtractive hybridization from RNA derived from mesenteric lymph nodes (MLN) cells from mice pre-immunized with allogeneic lymphocytes 36hrs prior to receiving donor-specific skin grafts, and showing > 98% homology with a published sequence for the rat MRC OX-2 gene, was used as a hybridization probe to screen a cDNA library constructed from adult mouse MLN treated in the same fashion. Several clones were identified which, on DNA sequence analysis, predicted a 218 amino acid protein showing significant homology with the rat and human MRC OX-2 gene product.

[The technology of real time telemetring and monitoring multi-channels ECGs through public telephone network]

In this essay a kind of technology of real time telemetring and monitoring multi channels ECGs through public telephone network is presented. Two limb leaders (I and II) ECG signals are transmitted from the sender at first. After they are received by the receiver the other four limb leaders are calculated by computer in the basis of the relation among the limb leaders, the received waveform and the calculated waveform are just the same as those described directly by Electro Cardiograph. After the limb leaders ECG signals (34 s) are transmitted, two selectable thorax leaders ECG signals are transmitted for 34 seconds after automatically changing the leaders. The received ECG waves are displayed on screen real time, shifting smoothly. After transmission doctors may make diagnoses and give some suggestion for treatment. Thus, telemetrying and monitoring multi channels ECGs is realized.

Specificity for in vivo graft prolongation in gamma delta T cell receptor+ hybridomas derived from mice given portal vein donor-specific preimmunization and skin allografts

gamma delta TCR+ hybridoma cells prepared from mesenteric lymph node cells of animals receiving donor-specific immunization via the portal vein can adoptively transfer this increased graft survival to naive animals. Analysis of TCR gamma-chain junctional sequence diversity suggested that some 40 to 50% of the hybridomas expressed gamma-chain junctional sequence diversity and were stimulated to produce cytokines both by heat shock proteins and by minor histocompatibility Ag-specific irradiated peritoneal cells. The remaining gamma delta TCR+ hybridoma cells expressed TCR with a common gamma-chain junctional sequence and were stimulated to cytokine production by MHC-matched, but minor histocompatibility Ag-mismatched (as well as matched), peritoneal cells, but not by heat shock proteins. We have compared the effectiveness of representative hybridomas expressing unique gamma-chain junctional sequences or common gamma-chain junctional sequences for prolongation of donor-specific or third-party (MHC-matched or MHC-mismatched) skin grafts. Our data show a good correlation between the specificity for stimulation for cytokine production in vitro and efficacy in graft prolongation assays in vivo. Hybridoma cells expressing unique gamma-chain junctional sequences that showed Ag-specific stimulation of cytokine production in vitro and skin graft survival in vivo augmented survival of third-party skin grafts if simultaneously transplanted with both Ag-specific and third-party skin grafts. Graft prolongation in vivo using cells from either population of gamma delta TCR+ hybridomas was decreased by infusion of anti-IL-10 mAb and abolished when both anti-IL-10 and anti-TGF-beta Abs were used together.

Specificity for in vivo graft prolongation in gamma delta T cell receptor+ hybridomas derived from mice given portal vein donor-specific preimmunization and skin allografts

gamma delta TCR+ hybridoma cells prepared from mesenteric lymph node cells of animals receiving donor-specific immunization via the portal vein can adoptively transfer this increased graft survival to naive animals. Analysis of TCR gamma-chain junctional sequence diversity suggested that some 40 to 50% of the hybridomas expressed gamma-chain junctional sequence diversity and were stimulated to produce cytokines both by heat shock proteins and by minor histocompatibility Ag-specific irradiated peritoneal cells. The remaining gamma delta TCR+ hybridoma cells expressed TCR with a common gamma-chain junctional sequence and were stimulated to cytokine production by MHC-matched, but minor histocompatibility Ag-mismatched (as well as matched), peritoneal cells, but not by heat shock proteins. We have compared the effectiveness of representative hybridomas expressing unique gamma-chain junctional sequences or common gamma-chain junctional sequences for prolongation of donor-specific or third-party (MHC-matched or MHC-mismatched) skin grafts. Our data show a good correlation between the specificity for stimulation for cytokine production in vitro and efficacy in graft prolongation assays in vivo. Hybridoma cells expressing unique gamma-chain junctional sequences that showed Ag-specific stimulation of cytokine production in vitro and skin graft survival in vivo augmented survival of third-party skin grafts if simultaneously transplanted with both Ag-specific and third-party skin grafts. Graft prolongation in vivo using cells from either population of gamma delta TCR+ hybridomas was decreased by infusion of anti-IL-10 mAb and abolished when both anti-IL-10 and anti-TGF-beta Abs were used together.