Migration behavior and separation of sulfonamides in capillary zone electrophoresis. I. Influence of buffer pH and electrolyte modifier

The influence of buffer pH and electrolyte modifier on the migration behavior and separation of thirteen sulfonamides was investigated by capillary zone electrophoresis. The results indicate that precise optimization of buffer pH is crucial in improving the separation of some closely migrating sulfonamides. On the addition of either an appropriate amount of an organic modifier (methanol or acetonitrile) or a low concentration of beta-cyclodextrin (beta-CD, 0.5 mM) to a phosphate-borate buffer at pH 6.85 and an applied voltage of 20 kV, the resolution of peaks between sulfathiazole and sulfamethoxypyridarine is markedly enhanced and effective separations of thirteen sulfonamides are achieved within a relatively short time. Methanol gives better resolution than acetonitrile as an organic modifier. Weak inclusion complexation occurs between beta-CD and sulfonamides, with the exception of sulfathiazole. The formation constants of thirteen sulfonamides with beta-CD are reported.

Lack of NK cells and related cytokines in pleural effusion

BACKGROUND

Relatively low number and activity of natural-killer (NK) cells have been reported in malignant pleural effusions. However, there has been no report on NK cells related cytokines.

METHODS

Lymphocyte subpopulations were studied in 30 cases of pleural effusion with various etiologies, along with peripheral blood, by using flow cytometry. The related cytokine levels in peripheral blood and pleural fluid, including IL-1 alpha, IL-4 and IL-12, were also analyzed with ELISA assays.

RESULTS

The results showed significant increase of T-helper cell subpopulation in pleural effusion of various etiologies. No obvious change of B-lymphocyte subpopulation between peripheral blood and pleural effusion was found. IL-4 was undetectable in both peripheral blood and pleural fluid in most cases. IL-1 alpha was detectable in some cases and the level was highest in pleural fluid of empyema. Decreased NK cells were found in most cases of pleural effusion and accompanied by undetectable IL-12 both in pleural fluid and peripheral blood. The only one case with detectable IL-12 concentration in pleural fluid was the one with tuberculous pleurisy.

CONCLUSIONS

Increased T-helper cell subpopulation and decreased NK cell subpopulation were found in pleural effusion of various etiologies. In spite of the small series of our patients, the decrease of NK cell subpopulation and the undetectable IL-12 concentration in pleural effusion deserves further investigations.

A comparative study on commercial samples of the roots of Paeonia vitchii and P. lactiflora

A total of 37 commercial samples of paeoniae radix (Paeonia lactiflora Pall. = P. albiflora Pall, and P. vitchii Lynch), were collected from Taiwan's herbal market. The contents of eight constituents (gallic acid, oxypaeoniflorin, albiflorin, paeoniflorin, benzoic acid, pentagalloylglucose, paeonol, and benzyoylalbiflorin) in these samples were determined by high-performance liquid chromatography. It was found that constituent contents in P. lactiflora samples were generally higher than in P. vitchii samples except for the albiflorin/oxypaeoniflorin ratio and paeonol content. The major compounds of P. lactiflora were paeoniflorin, albiflorin, and pentagalloylglucose, while those in P. vitchii were paeoniflorin, pentagalloylglucose, and oxypaeoniflorin. The peak-area ratio of albiflorin/oxypaeoniflorin was higher than unity in P. lactiflora samples but lower than unity in P. vitchii, and the ratio can be used to differentiate the origin of Paeonia species clearly. In addition, the former had higher contents in the core wood but the latter in the cortex.

Dynamics of tissue optics during laser heating of turbid media

The dynamics of the optical behavior of tissue during the photothermal interaction of laser radiation with tissue could significantly affect the optimization of light doses for effective and safe applications of lasers in medicine. Characterization of the dynamics of tissue optics during laser heating was performed by means of simultaneous measurements of the total transmittance, diffuse reflectance, and surface temperature of fresh and thermally coagulated human skin and canine aorta during long-pulsed Nd:YAG laser heating with a double integrating-sphere system and an infrared camera. Thermally induced changes in the optical properties of tissue caused a decrease in the total transmittance and an increase in the diffuse reflectance of both fresh and precoagulated skin and aorta samples. For fresh tissue, these changes were primarily reversible until photocoagulation occurred, then both the reversible, as well as the irreversible, changes were observed. However, for precoagulated tissue the reversible changes in the optical properties were dominant, whereas the irreversible changes were insignificant. Results from this study indicate the existence of the nonlinear behavior in the optics of turbid biological media during pulsed laser heating. Possible mechanisms responsible for this nonlinear optical behavior are discussed.

Characterization of guanine and hypoxanthine phosphoribosyltransferases in Methanococcus voltae

Phosphoribosyltransferase (PRTase) and nucleoside phosphorylase (NPase) activities were detected by radiometric methods in extracts of Methanococcus voltae. Guanine PRTase activity was present at 2.7 nmol min(-1) mg of protein(-1) and had an apparent Km for guanine of 0.2 mM and a pH optimum of 9. The activity was inhibited 50% by 0.3 mM GMP. IMP and AMP were not inhibitory at concentrations up to 0.6 mM. Hypoxanthine inhibited by 50% at 0.16 mM, and adenine and xanthine were not inhibitory at concentrations up to 0.5 mM. Guanosine NPase activity was present at 0.01 nmol min(-1) mg of protein(-1). Hypoxanthine PRTase activity was present at 0.85 nmol min(-1) mg of protein(-1) with an apparent Km for hypoxanthine of 0.015 mM and a pH optimum of 9. Activity was stimulated at least twofold by 0.05 mM GMP and 0.2 mM IMP but was unaffected by AMP. Guanine inhibited by 50% at 0.06 mM, but adenine and xanthine were not inhibitory. Inosine NPase activity was present at 0.04 nmol min(-1) mg of protein(-1). PRTase activities were not sensitive to any base analogs examined, with the exception of 8-azaguanine, 8-azahypoxanthine, and 2-thioxanthine. Fractionation of cell extracts by ion-exchange chromatography resolved three peaks of activity, each of which contained both guanine and hypoxanthine PRTase activities. The specific activities of the PRTases were not affected by growth in medium containing the nucleobases. Mutants of M. voltae resistant to base analogs lacked PRTase activity. Two mutants resistant to both 8-azaguanine and 8-azahypoxanthine lacked activity for both guanine and hypoxanthine PRTase. These results suggest that analog resistance was acquired by the loss of PRTase activity.

Divergent phosphotyrosine signaling via Fc gamma RIIIA on human NK cells

Previous studies have indicated that interaction of Fc gamma RIIIA on natural killer (NK) cells with various immunoglobulin ligands or monoclonal antibodies (mAbs) can have either stimulatory or inhibitory effects on cytotoxic activity, but the basis for such divergent functional effects has been unclear. We report here that stimulation of NK cells via Fc gamma RIIIA by monoclonal anti-human CD16 (3G8), monomeric IgG (mIgG), or dimeric IgG (dIgG), used either alone or cross-linked by secondary Ab (goat anti-mouse IgG or goat anti-human IgG), resulted in different phosphotyrosine protein patterns. These results suggest that distinct substrates are involved in signaling pathways activated via various agonists of the same triggering surface molecule. Three protein tyrosine kinases, i.e., LCK, LYN, and SYK, were activated by occupancy of the Fc gamma RIIIA, and only LCK activity showed a divergence in effects induced by the various ligands, with strong autophosphorylation induced by mIgG upon cross-linking. We observed no ligand-induced activation of p59fyn, p60c-src, or p62c-yes, src-related protein tyrosine kinases which are expressed in NK cells. Activity of phosphatidylinositol 3-kinase (PI 3-kinase) induced by receptor-specific antibodies or IgG ligands had different kinetics while the level of cytoplasmic free calcium was greatest upon 3G8-induced stimulation. Although the changes in kinase activities associated with Fc gamma RIIIA-mediated regulation of NK cells are complex, it appears that the patterns induced varied with the nature of the ligand and the direction of the regulation of NK activity.

Relaxant effects of berberine on the rat fundus

The present study examines the relaxant effect of berberine on the longitudinal muscle of the isolated rat gastric fundus. Our experiments show that berberine reduces the tonic contraction more than the phasic contraction induced by carbachol. In addition, the carbachol induced phasic contraction in Ca+2 -free solution was only inhibited at the highest concentration of berberine. Berberine inhibited the slow phase more than the fast phase in KCl-induced contractions. These results suggest that the major mechanism of berberine consists of an inhibition of calcium entry from extracellular in the second phase induced by both carbachol and KCl. Conversely, prevention of the mobilization of store Ca+2 in the phasic contraction phase induced by carbachol and prevention of the calcium entry from extracellular in first phase elicited by high levels of potassium play only a minor role in the dilatory effect of berberine.

Nonlinear optical behavior of ocular tissue during laser irradiation

A pump (cw Ho-YAG laser) and probe (He-Ne laser) system was used to study the dynamics of the optical behavior of ocular tissue during laser heating. The nonlinear optical behavior of porcine corneal and vitreous-humor tissue was characterized in vitro by means of measurements of the radial profile of a He-Ne laser beam transmitted through the tissue. Temperature gradients in the tissue created by the absorption of pump radiation caused the probe beam to diverge. For constant laser power, the rate of divergence was made dependent on the spot size of the pump beam. The profile of the transmitted probe beam returned to its original magnitude and shape after the tissue was permitted to cool. This reversible change in optical behavior was attributed to the formation of a negative lens owing to thermally induced local gradients in the refractive index of the tissue.

Cloning and characterization of a cDNA encoding an 18.0-kDa class-I low-molecular-weight heat-shock protein from rice

A novel cDNA clone, Oshp18.0 cDNA, encoding a rice (Oryza sativa L. cv. Tainong 67) 18.0-kDa heat-shock protein (HSP), was isolated from a cDNA library of heat-shocked rice seedlings by use of the rice HSP cDNA, Oshsp17.3 cDNA, as a probe. The sequence showed that Oshsp18.0 cDNA contains a 749-bp insert encoding an ORF of 160 amino acids, with a predicted molecular mass of 18.0 kDa and a pI of 7.3. Sequence comparison reveals that Oshsp18.0 cDNA is highly homologous to other low-molecular-weight (LMW) HSP cDNAs. Also, the results of hybrid-selected in vitro translation clearly establish that Oshsp18.0 cDNA is the rice 18.0-kDa LMW HSP-encoding cDNA clone. The recombinant Oshsp18.0 fusion protein produced in Escherichia coli was of the size predicted, and was recognized by the class-I rice 16.9-kDa HSP antiserum. The results suggest that Oshsp18.0 cDNA is an 18.0-kDa class-I LMW HSP- encoding cDNA clone from rice.

Constitutive production of IL-2 by human carcinoma cells, expression of IL-2 receptor, and tumor cell growth

Human carcinomas spontaneously express abundant IL-2R beta but little IL-2R alpha on the cell surface, contain mRNA for IL-2R beta- and IL-2R alpha-chains, and may be inhibited in growth by exogenous IL-2. To study the relationship between IL-2R expression and growth inhibition by IL-2, carcinoma cells were transduced with IL-2R alpha and IL-2R gamma cDNAs or IL-2R beta antisense cDNA. Transfectants with the IL-2R alpha gene expressed high levels of the alpha- and beta-receptor chains and showed increased binding of [125I]IL-2. Exogenous IL-2 at the picometer concentrations inhibited their growth, and Abs to IL-2R alpha- or IL-2R beta-chains reversed the inhibition. After transduction of IL-2R beta antisense cDNA, gastric carcinoma (HR) cells no longer expressed IL-2R beta-chain, and their proliferation was depressed in the absence of exogenous IL-2. Transduction of IL-2R gamma-chain cDNA into tumor cells increased sensitivity to growth inhibition by exogenous IL-2 of a squamous cell carcinoma line, but not of HR or renal cell carcinoma lines. All of the parental and transduced tumor cell lines were found to constitutively express intracellular IL-2, detectable by immunostaining or flow cytometry of permeabilized cells. IL-2 was present on the surface of some tumor cells. Intracellular IL-2R beta and IL-2R gamma proteins were also detectable in tumor cells. Using reverse-transcription PCR combined with Southern blots or in situ hybridization, mRNA for IL-2 was found to be present in parental and transduced tumor cells. Expression on human carcinomas of IL-2R beta, inhibition of their growth by IL-2R beta antisense cDNA, and their ability to constitutively produce IL-2 and its presence on the cell surface, all suggest that endogenous IL-2 may play a role in tumor cell growth.

Constitutive production of IL-2 by human carcinoma cells, expression of IL-2 receptor, and tumor cell growth

Human carcinomas spontaneously express abundant IL-2R beta but little IL-2R alpha on the cell surface, contain mRNA for IL-2R beta- and IL-2R alpha-chains, and may be inhibited in growth by exogenous IL-2. To study the relationship between IL-2R expression and growth inhibition by IL-2, carcinoma cells were transduced with IL-2R alpha and IL-2R gamma cDNAs or IL-2R beta antisense cDNA. Transfectants with the IL-2R alpha gene expressed high levels of the alpha- and beta-receptor chains and showed increased binding of [125I]IL-2. Exogenous IL-2 at the picometer concentrations inhibited their growth, and Abs to IL-2R alpha- or IL-2R beta-chains reversed the inhibition. After transduction of IL-2R beta antisense cDNA, gastric carcinoma (HR) cells no longer expressed IL-2R beta-chain, and their proliferation was depressed in the absence of exogenous IL-2. Transduction of IL-2R gamma-chain cDNA into tumor cells increased sensitivity to growth inhibition by exogenous IL-2 of a squamous cell carcinoma line, but not of HR or renal cell carcinoma lines. All of the parental and transduced tumor cell lines were found to constitutively express intracellular IL-2, detectable by immunostaining or flow cytometry of permeabilized cells. IL-2 was present on the surface of some tumor cells. Intracellular IL-2R beta and IL-2R gamma proteins were also detectable in tumor cells. Using reverse-transcription PCR combined with Southern blots or in situ hybridization, mRNA for IL-2 was found to be present in parental and transduced tumor cells. Expression on human carcinomas of IL-2R beta, inhibition of their growth by IL-2R beta antisense cDNA, and their ability to constitutively produce IL-2 and its presence on the cell surface, all suggest that endogenous IL-2 may play a role in tumor cell growth.

Effect of intracerebroventricular and intrahypothalamic administrations of picrotoxin on basal and stimulated gastric acid secretion

The effects of intracerebroventricular and intrahypothalamic injections of picrotoxin, a GABA antagonist, on gastric acid secretion were studied in perfused stomachs of rats under anesthesia. Injection of picrotoxin into the lateral cerebroventricle inhibited the 2-deoxy-D-glucose-stimulated acid secretion. In experiments of intrahypothalamic injections, picrotoxin produced a significant depression of 2-deoxy-D-glucose-stimulated acid secretion when administered to the ventromedial hypothalamus but not to the lateral hypothalamus. In contrast, picrotoxin produced a definite stimulatory effect on basal acid secretion when injected to the lateral hypothalamus or ventromedial hypothalamus; the stimulatory effect of the injection to the lateral hypothalamus was greater than that of the injection to the ventromedial hypothalamus. These findings indicate that picrotoxin acts centrally, probably hypothalamus, to depress the 2-deoxy-D-glucose-stimulated acid secretion. On the other hand, blockade of GABA activity in the lateral hypothalamus or ventromedial hypothalamus may elicit gastric acid secretion. These results, indicate that central GABAergic mechanism is important in regulating gastric acid secretion in the rat.

Stimulatory effect of muscimol on gastric acid secretion stimulated by secretagogues in vagotomized rats under anesthesia

The effect of intravenous administration of muscimol, a GABAA receptor agonist, on gastric acid secretion from perfused stomach was studied in vagotomized rats anesthetized with urethane. Muscimol did not stimulate acid secretion by itself. In contrast, muscimol dose dependently potentiated acid secretion induced by pentagastrin, bethanechol and direct vagal stimulation, but not histamine. Muscimol-potentiated acid secretion induced by pentagastrin and bethanechol was not influenced by pretreatment with atropine or cimetidine, respectively. Muscimol-potentiated acid secretion evoked by direct vagal stimulation was prevented by pretreatment with proglumide, a gastrin receptor antagonist. Muscimol-potentiated acid secretion evoked by bethanechol was dose dependently prevented by bicuculline methiodide, suggesting an involvement of peripheral GABAA receptors. These results suggest that muscimol stimulates acid secretion under certain conditions, and that two mechanisms are involved in this effect. The effects of muscimol on acid secretion may be mediated by increasing the release of histamine by pentagastrin, bethanechol and direct vagal stimulation. In addition, muscimol would also be effective if muscarinic agents were already occupying muscarinic acetylcholine receptors on parietal cells.

V(D)J recombination and the cell cycle

V(D)J recombination is a major source of antigen receptor diversity and represents the only known form of site-specific DNA rearrangement in vertebrates. V(D)J recombination is initiated by specific DNA cleavage at recombinational signal sequences and requires components of the general machinery used for double-strand (DS)-break repair. The involvement of DS cleavage and repair mechanisms suggests that V(D)J recombination might be coupled to the cell cycle, as introduction or persistence of DS breaks during DNA replication or mitosis could interfere with faithful transmission of genetic information to daughter cells. Here, Weei-Chin Lin and Stephen Desiderio review recent evidence indicating that this is indeed the case and consider some biological implications of this linkage.

Induction of protein tyrosine phosphorylation in human natural killer cells by triggering via alpha 4 beta 1 or alpha 5 beta 1 integrins

Recent studies have shown that cell-surface integrins expressed on platelets, fibroblasts, or carcinoma cell lines serve not only as adhesion receptors that connect the extracellular matrix to the cytoskeleton, but also as signal-transducing molecules involved in altering cellular patterns of tyrosine phosphorylation. In this present report we provide evidence that adhesion of freshly purified human natural killer (NK) cells to fibronectin (FN) induces tyrosine phosphorylation of intracellular proteins of approximate molecular mass of 60, 70, and 120 kD. Increases in phosphorylation induced by NK cell binding to immobilized FN were partially blocked by EILDV- (CS-1) or RGD-containing peptides, which compete specifically for a distinct binding site for either alpha 4 beta 1 or alpha 5 beta 1 integrins, respectively, within the FN molecule. The presence of either one of the inhibitory peptides alone inhibited tyrosine phosphorylation primarily during short-term (30 minutes) and, to a lesser extent, during long-term (2 to 3 hours) periods of adhesion. These observations indicate that triggering either via alpha 4 beta 1 or alpha 5 beta 1 integrins, which are constitutively expressed on NK cells, induces protein tyrosine phosphorylation. Moreover, FN fragments of 40 or 120 kD, known to contain the binding sites for alpha 4 beta 1 or alpha 5 beta 1 integrins, respectively, used as immobilized substrates for NK cell adhesion, were able to initiate tyrosine kinase activity. The induced tyrosine phosphorylation was observed mainly on intracellular proteins of greater than 50 kD molecular weight. We have identified a 70-kD tyrosine phosphoprotein as paxillin, a cytoskeletal-associated tyrosine kinase substrate previously identified in fibroblasts and shown to localize to focal adhesions. Thus, interaction of NK cells with immobilized extracellular matrix glycoproteins required for migration and extravasation of these cells involves activation of intracellular protein tyrosine kinases and tyrosine phosphorylation of cytoskeleton-associated protein, paxillin, which may play a role in signaling between beta 1 integrins and the underlying cytoskeleton.

Production by human squamous cell carcinoma of a factor inducing activation and proliferation of immune cells

OBJECTIVE

To examine supernatants (SNs) of human squamous cell carcinoma of the head and neck cell lines for soluble tumor-derived factors capable of inducing activation and proliferation of human immune cells.

DESIGN

The SN of squamous cell carcinoma of the head and neck cell line PCI-50 was cultured in serum-free medium and tested for the ability to induce expression of activation antigens, proliferation, cytotoxicity against tumor cell targets and cytokine production by purified human natural killer (NK) and CD4+ T cells.

RESULTS

Supernatant of PCI-50 promoted expression of the following activation markers on NK and T cells: CD25 (interleukin-2R-alpha), HLA-DR (major histocompatibility complex class II), CD54 (ICAM-1), CD71 (transferrin receptor), and CD69 (activation-inducing molecule). In addition, SN induced and significantly sustained (P < .01) proliferation of human unseparated peripheral blood lymphocytes and NK or T cells in culture. Purified human NK or T cells cultured in the presence of the SN and IL-2 (120 IU/mL) had significantly higher antitumor cytotoxicity than that mediated by NK or T cells cultured in AIM-V medium and IL-2. The SN induced cytokine (interferon gamma, tumor necrosis factor alpha, interleukin-6) production in purified NK or T cells. When the SN was fractionated by molecular weight-based filtration into fractions greater and less than 30 kd, the growth- and cytotoxicity-promoting activities were consistently detectable in the greater than 30-kd fraction.

CONCLUSIONS

Culture SN of squamous cell carcinoma of the head and neck cell lines contain a soluble factor(s) capable of activating NK and CD4+ T cells and of promoting growth and antitumor cytotoxicity of these lymphocyte subsets in vitro.

Expression of vitronectin receptor on human NK cells and its role in protein phosphorylation, cytokine production, and cell proliferation

In this paper, we provide evidence that the vitronectin receptor (VNR) alpha v beta 3 is expressed on human NK cells. The presence of this VNR on freshly purified NK cells was demonstrated by flow cytometry analysis, as well as biochemically, after 125I-labeled surface lactoperoxidase labeling and immunoprecipitation. mAbs LM142 and LM609 specific for alpha v and alpha v beta 3, respectively, precipitated a heterodimer of alpha- and beta-chains with approximate molecular masses of 155 and 110 kDa under nonreducing conditions. Under reducing conditions, there was an apparent decrease in the molecular mass of the alpha-chain, which is likely to result from the release of a protein of 20 to 30 kDa linked by internal disulfide bond to the alpha v-chain. Integrin alpha v beta 3 expressed on NK cells became functional, i.e., was able to bind its ligand, vitronectin (VN), only after cellular activation or when costimulation with an additional signal was provided. Thus, NK cells adhered to plastic-immobilized VN only after IL-2 activation, and RGD-containing synthetic peptides or mAbs specific for alpha v beta 3 complex inhibited this binding. To assess the role of the VNR in signal transduction, anti-beta 3 mAb was used to cluster the VNR on NK cells and, thereby, mimic the process that occurs during formation of adhesive contacts. Cross-linking of VNR on fresh NK cells stimulated phosphorylation on tyrosine residues of several intracellular proteins. The major increase in tyrosine phosphorylation was observed in proteins of approximate molecular masses of 75 and 120 kDa. Therefore, signal transduction by the VNR on NK cells induced activation of intracellular protein kinases. Ligand engagement of the VNR on NK cells also costimulated cytokine production and proliferation of NK cells. Binding of NK cells to plastic-immobilized VN served as a costimulus with either anti-Fc gamma RIII or IL-2 to produce IFN-gamma, TNF-alpha, and cell proliferation. Our findings suggest that occupancy and subsequent clustering of VNRs play a role in the activation and function of human NK cells.

Expression of vitronectin receptor on human NK cells and its role in protein phosphorylation, cytokine production, and cell proliferation

In this paper, we provide evidence that the vitronectin receptor (VNR) alpha v beta 3 is expressed on human NK cells. The presence of this VNR on freshly purified NK cells was demonstrated by flow cytometry analysis, as well as biochemically, after 125I-labeled surface lactoperoxidase labeling and immunoprecipitation. mAbs LM142 and LM609 specific for alpha v and alpha v beta 3, respectively, precipitated a heterodimer of alpha- and beta-chains with approximate molecular masses of 155 and 110 kDa under nonreducing conditions. Under reducing conditions, there was an apparent decrease in the molecular mass of the alpha-chain, which is likely to result from the release of a protein of 20 to 30 kDa linked by internal disulfide bond to the alpha v-chain. Integrin alpha v beta 3 expressed on NK cells became functional, i.e., was able to bind its ligand, vitronectin (VN), only after cellular activation or when costimulation with an additional signal was provided. Thus, NK cells adhered to plastic-immobilized VN only after IL-2 activation, and RGD-containing synthetic peptides or mAbs specific for alpha v beta 3 complex inhibited this binding. To assess the role of the VNR in signal transduction, anti-beta 3 mAb was used to cluster the VNR on NK cells and, thereby, mimic the process that occurs during formation of adhesive contacts. Cross-linking of VNR on fresh NK cells stimulated phosphorylation on tyrosine residues of several intracellular proteins. The major increase in tyrosine phosphorylation was observed in proteins of approximate molecular masses of 75 and 120 kDa. Therefore, signal transduction by the VNR on NK cells induced activation of intracellular protein kinases. Ligand engagement of the VNR on NK cells also costimulated cytokine production and proliferation of NK cells. Binding of NK cells to plastic-immobilized VN served as a costimulus with either anti-Fc gamma RIII or IL-2 to produce IFN-gamma, TNF-alpha, and cell proliferation. Our findings suggest that occupancy and subsequent clustering of VNRs play a role in the activation and function of human NK cells.

Antitumor activities of subsets of human IL-2-activated natural killer cells in solid tissues

Human NK cells can be separated into two functionally distinct subpopulations based on the ability to rapidly respond to IL-2 by adherence to solid surfaces. To determine functions of the NK cell subsets in solid tumor tissues, adherent (A) and nonadherent (NA) NK cells were evaluated for their ability to infiltrate multicellular tumor spheroids in vitro, to kill carcinoma (CA) cell targets in these spheroids, and to mediate antitumor activity in vivo. A-NK cells were less cytolytic than NA-NK cells against CA targets in single cell suspensions or in monolayers. However, A-NK cells showed a significantly better ability than NA-NK cells to infiltrate tumor tissues and kill tumor cells in spheroids of human squamous cell CA of the head and neck or breast CA. Perilesional delivery of human A-NK cells and IL-2 resulted in regression of established human squamous cell carcinoma of the head and neck tumors growing subcutaneously in immunosuppressed nude mice. Similarly, in a xenograft model of human gastric CA metastatic to liver of nude mice, a single intrasplenic injection of A-NK cells in combination with i.p. infusions of IL-2 significantly reduced the number of established hepatic metastases (p < 0.007) and prolonged survival of the mice (p < 0.003). In contrast, NA-NK cells were ineffective in either of the in vivo xenograft tumor models. These findings demonstrate that A-NK cells represent a biologically unique and important subset of NK cells that, in contrast to the rest of NK cells, function as effector cells in solid tumor tissues and, consequently, have a great antitumor therapeutic potential.

Antitumor activities of subsets of human IL-2-activated natural killer cells in solid tissues

Human NK cells can be separated into two functionally distinct subpopulations based on the ability to rapidly respond to IL-2 by adherence to solid surfaces. To determine functions of the NK cell subsets in solid tumor tissues, adherent (A) and nonadherent (NA) NK cells were evaluated for their ability to infiltrate multicellular tumor spheroids in vitro, to kill carcinoma (CA) cell targets in these spheroids, and to mediate antitumor activity in vivo. A-NK cells were less cytolytic than NA-NK cells against CA targets in single cell suspensions or in monolayers. However, A-NK cells showed a significantly better ability than NA-NK cells to infiltrate tumor tissues and kill tumor cells in spheroids of human squamous cell CA of the head and neck or breast CA. Perilesional delivery of human A-NK cells and IL-2 resulted in regression of established human squamous cell carcinoma of the head and neck tumors growing subcutaneously in immunosuppressed nude mice. Similarly, in a xenograft model of human gastric CA metastatic to liver of nude mice, a single intrasplenic injection of A-NK cells in combination with i.p. infusions of IL-2 significantly reduced the number of established hepatic metastases (p &lt; 0.007) and prolonged survival of the mice (p &lt; 0.003). In contrast, NA-NK cells were ineffective in either of the in vivo xenograft tumor models. These findings demonstrate that A-NK cells represent a biologically unique and important subset of NK cells that, in contrast to the rest of NK cells, function as effector cells in solid tumor tissues and, consequently, have a great antitumor therapeutic potential.

Anti-inflammatory and hepatoprotective effects of Solanum alatum

Solanum alatum aqueous extract was investigated on carrageenin-induced edema and on CCl4-induced liver injury. The extract (100 or 200 mg/kg body weight) exhibited both anti-inflammatory and hepatoprotective activities. The effects were more prominent at the dose of 200 mg/kg. Histological changes such as necrosis, fatty changes, ballooning degeneration, and inflammatory infiltration of lymphocytes and Kupffer cells around the central veins were concurrently improved by treatment with the S. alatum aqueous extract.

Artificial neural networks for 3-D motion analysis. I. Rigid motion

Proposes an approach applying artificial neural net techniques to 3D rigid motion analysis based on sequential multiple time frames. The approach consists of two phases: (1) matching between every two consecutive frames and (2) estimating motion parameters based on the correspondences established. Phase 1 specifies the matching constraints to ensure a stable and coherent feature correspondence establishment between two sequential time frames and configures a 2D Hopfield neural net to enforce these constraints. Phase 2 constructs a 3-layer net to estimate parameters through supervised learning. The method performs motion analysis based on sequential multiple time frames. It represents an effective way to achieve optimal matching between two frames using neural net techniques. The energy function of the Hopfield net is designed to reflect the matching constraints and the minimization of this function leads to the optimal feature correspondence establishment. The approach introduces the learning concept to motion estimation. The structure of the net provides the flexibility in estimating motion parameters based on information from multiple frames.

Artificial neural networks for 3-D motion analysis-Part II: Nonrigid motion

For pt. I see ibid., p. 1386-93 (1995). An approach applying artificial neural net techniques to 3D nonrigid motion analysis is proposed. The 3D nonrigid motion of the left ventricle of a human heart is examined using biplanar cineangiography data, consisting of 3D coordinates of 30 coronary artery bifurcation points of the left ventricle and the correspondences of these points taken over 10 time instants during the heart cardiac cycle. The motion is decomposed into global rigid motion and a set of local nonrigid deformations which are coupled with the global motion. The global rigid motion can be estimated precisely as a translation vecto and a rotation matrix. Local nonrigid deformation estimation is discussed. A set of neural nets similar in structure and dynamics but different in physical size is proposed to tackle the problem of nonrigidity. These neural networks are interconnected through feedbacks. The activation function of the output layer is selected so that a feedback is involved in the output updating. The constraints are specified to ensure stable and globally consistent estimation. The objective is to find the optimal deformation matrices that satisfy the constraints for all coronary artery bifurcation points of the left ventricle. The proposed neural networks differ from other existing neural network models in their unique structure and dynamics.

The role of gastric muscle relaxation in cytoprotection induced by san-huang-xie-xin-tang in rats

We examined the mechanism of the protective effect of San-huang-xie-xin-tang (SHXT), a traditional oriental drug, on the gastric mucosa. SHXT, given intraduodenally, inhibited the gastric secretion in pylorus-ligated rats. SHXT, given orally 30 min before the administration of aspirin, HCl-aspirin and ethanol, protected the gastric mucosa from these agent-induced gastric lesions, although it had no effect on the gastric lesions induced by indomethacin and water immersion stress. Oral administration of SHXT increased gastric contents (muscle relaxation) when they were measured 30 min after SHXT administration. SHXT also inhibited carbachol-contracted gastric muscle in vitro. Neither increased gastric contents nor inhibited ethanol lesions of SHXT were observed when these were tested 4 h after SHXT administration. Pretreatment with indomethacin which is a prostaglandin synthesis inhibitor, and N-ethylmaleimide which is a sulfhydryl blocker did not influence either the increased gastric contents or inhibited ethanol lesions of SHXT. These results indicate that gastric muscle relaxation plays an important role in the gastric protective mechanisms of SHXT, and the endogenous prostaglandins and the sulfhydryl compounds are not necessary for the action of SHXT.