Evaluation of the behavior of murine and human embryonic stem cells in in vitro migration and invasion assays.

Cell migration and invasion are essential processes in a variety of physiological events in the body, but also in several patho-physiological events. In this paper, the behavior of murine and human embryonic stem cells is examined in in vitro migration and invasion models. mESC and hESC were applied as spheroids, also known as patches, and as single cells, to mimic possible cell therapy application strategies. Two known in vitro migration assays, the ECM (extracellular matrix) assay and the Boyden chamber migration assay were selected. These assays revealed that mESC are statistically significantly more infiltrative than hESC. Application as spheroid results in a slightly higher infiltrative capacity compared single cells. The PHF (precultured chick heart fragment) assay was selected as an invasion assay. In the PHF assay a more 3D examination of the infiltrative nature of the ESC can be observed. The mESC showed infiltrative behavior, as spheroids and as single cells. The hESC were infiltrative as single cells but not as spheroids. The results of these assays are mostly complementary and prove the applicability of these assays, which were originally applied in tumor biology, in migratory behavior studies regarding stem cells and their progeny in basic and other conditions.

Platelet gel supernatant as a potential tool to repopulate acellular heart valves.

OBJECTIVE: The aim of this study was to repopulate decellularized heart valve matrices with ovine mesenchymal stem cells (oMSCs) by the use of platelet gel (PG) supernatant, a storage vehicle for growth factors. METHODS: oMSCs were exposed to different concentrations of PG-released supernatant and cell proliferation was evaluated using the MTS assay. oMSC motility and invasiveness were assayed using a Boyden chamber. A quantitative sandwich enzyme immunoassay was used to examine amounts of bFGF and TGF-ß1 in the PG supernatant. Repopulation of acellular heart valve matrices was stimulated by seeding matrices with oMSCs supplemented with the PG supernatant. RESULTS: The most significant increase in proliferation induced by PG supernatant appeared at 1 × 10(5) plts/ml concentration. Higher concentrations evoked reduction of the stimulatory process. oMSC motility was most significantly stimulated at 1 × 10(6) plts/ml. Stimulating invasiveness of oMSCs needed the much higher concentration of 2 × 10(6) plts/ml. Immunoassays revealed that sheep PG supernatant contains 184.8 pg/ml bFGF and 60.5 ng/ml TGF-ß1. Moreover, repopulation of acellular heart valve matrices was significantly enhanced by PG supernatant addition and resulted in upregulation of the myofibroblast marker alpha-smooth muscle actin. CONCLUSIONS: Growth factors released from platelets had the potential to induce cell repopulation in a heart valve tissue engineering procedure, through stimulation of mesenchymal stem-cell migration and invasion.

Electron spin resonance observation of an interfacial Ge P(b 1)-type defect in SiO(2)/(100)Si(1-x)Ge(x)/SiO(2)/Si heterostructures.

Using electron spin resonance (ESR), we report on the observation of a first Ge dangling bond (DB)-type interface defect in the SiO(2)/(100)Ge(x)Si(1-x)/SiO(2)/(100)Si heterostructure manufactured by the condensation technique. The center, exhibiting monoclinic-I (C(2v)) symmetry with principal g values g(1) = 2.0338 ± 0.0003, g(2) = 2.0386 ± 0.0006, g(3) = 2.0054 is observed in maximum densities of ∼6.8 × 10(12) cm(-2) of the Ge(x)Si(1-x)/SiO(2) interface for x∼0.7, the signal disappearing for x outside the 0.45-0.93 range. The notable absence of interfering Si P(b)-type centers enables unequivocal spectral analysis. Collectively, the combination of all data leads to depicting the defect as a Ge P(b 1)-type center, i.e. not a trigonal basic Ge P(b(0))-type center ([Formula: see text]). Understanding the modalities of the defect's occurrence may provide an insight into the thus far elusive role of Ge DB defects at Ge/insulator interfaces, and widen our understanding of interfacial DB centers in general.

Nitrobenzene compounds inhibit expression of VCAM-1.

A series of nitrobenzene compounds has been discovered as potent inhibitors of VCAM-1 expression and, therefore, potential drug candidates for autoimmune and allergic inflammatory diseases. Structure-activity relationship (SAR) studies showed that a nitro group and two other electron-withdrawing groups are essential for these compounds to be potent inhibitors of VCAM-1 expression.

Dithiocarbamates: effects on lipid hydroperoxides and vascular inflammatory gene expression.

Dithiocarbamates are a well-defined family of antioxidants that may have therapeutic uses such as in treatment of inflammation and atherosclerosis. A critical event in the pathogenesis of atherosclerosis is the infiltration of inflammatory cells into the vessel wall. Vascular cell adhesion molecule-1 (VCAM-1) plays a pivotal role in this process by mediating leukocyte binding to endothelial cells. VCAM-1 expression is stimulated by oxidized polyunsaturated fatty acids such as 13-hydroperoxy-octadecadienoic acid (13-HPODE), and this lipid hydroperoxide has been proposed to be a second messenger for induction of VCAM-1 gene expression. Pyrrolidine dithiocarbamate (PDTC) markedly represses cytokine-induced VCAM-1 gene expression in cultured human endothelial cells; however, its effects on the oxidative second messenger pathway are unknown. Using a lipoxygenase (LO) inhibition assay in tandem with a colorimetric assay for lipid peroxides, we determined that PDTC does not inhibit the enzymatic oxidation of linoleic acid to 13-HPODE by LO, but directly interacts with and chemically reduces 13-HPODE. We hypothesize that dithiocarbamates may intercept the oxidative second-messenger-induced expression of VCAM-1 and other redox-regulated genes important in inflammation and atherosclerosis.

Don't send us your huddled masses.

"The notion of the United States as ¿the mother of exiles' is an illusion, a legend perpetuated during an era when cheap immigrant labor was necessary to fuel the development of the country. The truth is that immigrants have been shunned for much of our history, tolerated only because their semiskilled labor was needed. Immigrant bashing was common, especially during times of economic distress. This article details the history of U.S. immigration and squarely places the current nativist sentiments in perspective."

Imposed and chosen monitoring and blunting strategies in the dental setting: Effects, self-efficacy, and coping preference.

Abstract In the present study, 94 dental patients received either monitoring (i.e., paying attention) or blunting (i.e., distraction) coping instructions during treatment. Half of the patients were given the possibility of choice, whereas the other half were offered one of both strategies without choice. A majority of the patients (n=61) indicated that the intervention had resulted in a decrease of their anxiety. Some indications were found for the monitoring strategy to be more effective than the blunting strategy. More specifically, monitoring strategy subjects reported that they had experienced less distress during treatment than blunting strategy subjects. In agreement with this finding, self-efficacy ratings of monitoring strategy subjects were higher than those of blunting strategy subjects. Possibility of choice and coping preference had no substantial influence on effectiveness of the interventions.

Probing immunosuppressant action with a nonnatural immunophilin ligand.

The immunosuppressants FK506 and rapamycin bind to the same immunophilin, FK506 binding protein (FKBP), and inhibit distinct signal transduction pathways in T lymphocytes. A nonnatural immunophilin ligand, 506BD, which contains only the common structural elements of FK506 and rapamycin, was synthesized and found to be a high-affinity ligand of FKBP and a potent inhibitor of FKBP rotamase activity. Whereas 506BD does not interfere with T cell activation, it does block the immunosuppressive effects of both FK506 and rapamycin. Thus, the common immunophilin binding element of these immunosuppressants, which is responsible for rotamase inhibition, is fused to different effector elements, resulting in the inhibition of different signaling pathways. Inhibition of rotamase activity is an insufficient requirement for mediating these effects.

The efficacy of biobehavioral and compliance interventions in the adjunctive treatment of mild pregnancy-induced hypertension.

This investigation assessed the efficacy of a biobehavioral intervention in the adjunctive treatment of mild pregnancy-induced hypertension (PIH), a potentially serious complication of pregnancy in which normotensive women develop hypertension, proteinuria, and edema of unknown etiology late in gestation. Forty-five women with symptoms of PIH were randomly assigned to one of three treatment conditions: bed rest alone (the most common obstetrical treatment), bed rest with individualized compliance enhancement training, or a four-session biobehavioral treatment consisting of bed rest, compliance enhancement training, and individualized thermal biofeedback-assisted relaxation training. Results indicated that while blood pressure for the bed rest and compliance enhancement groups continued to rise and pose an increasing health risk to maternal and fetal well-being, subjects in the biobehavioral group maintained their blood pressure at a significantly lower, and presumably safer, level. The biobehavioral treatment is hypothesized to affect blood pressure levels in subjects with mild PIH through the mediation of the sympathetic nervous system, decreasing peripheral vascular resistance and cardiac output. The results of this investigation suggest that the biobehavioral intervention may be an effective adjunct to bed rest in the treatment of mild PIH remote from term.

Method for the detection and quantitation of chitinase inhibitors in fermentation broths; isolation and insect life cycle effect of A82516.

A new method of screening for chitinase inhibitors in crude fermentation broths as a means of discovering new insecticidal leads has been developed. In this procedure soluble Remazol brilliant violet 5R dye-coupled chitin degradation products released from insoluble chitin azure substrate by hydrolysis with Streptomyces griseus chitinase are filtered in 0.45 micron Millititer HA 96 well filtration plates and collected in 96 well microtiter plates. Inhibitors of this reaction are detected by a decrease in absorbance (570 nm) of the filtrate. A chitinase inhibitor, designated A82516, produced by culture A82516 was discovered using this screen. Purified A82516 was found to have an IC50 of 3.7 X 10(-6) M for S. griseus chitinase. At a test concentration of 0.27 mg/ml, A82516 was 100% effective in preventing development of house fly larvae to pupae. Allosamidin, a recently reported chitinase inhibitor in vitro, has spectral properties identical to A82516.

The use of Champy miniplates for osteosynthesis in craniofacial deformities and trauma.

Champy miniplates have been used in the treatment of craniofacial fractures and in osteotomies for correction of posttraumatic deformities, congenital craniofacial deformities, and secondary bony deformities due to pathologies such as hemangioma and neurofibroma. An additional use has been to stabilize free and vascularized bone grafts. The total number of cases reviewed were 50 (25 acute trauma, 4 vascularized mandible reconstruction, and 21 osteotomies of varied types). There were three infections, two in mandibular fractures that were comminuted and compound into the mouth and one in a compound comminuted fracture of the frontal and maxillary area that was judged to be infected when the plate was placed in position. Two plates have been obvious under the skin. No patient has requested plate removal. The advantages of plating in selected cases are decreased operating time, rigid fixation at surgery, good fixation of bone grafts, and the ability to remove intermaxillary fixation in children at the end of the procedure or within the first few postoperative days.

Methods for the detection and quantitation of angiotensin converting enzyme inhibitors in fermentation broths.

Two procedures are described for the detection of inhibitors of angiotensin converting enzyme (ACE). The first is a new agar-plate method useful as a screening tool. Two ACE inhibitors produced by culture A58365 were discovered using this plate test. The second method is a modification of a previously reported spectrophotometric procedure. Both procedures utilize p-nitrobenzyl-oxycarbonylglycyl-(S-4-nitrobenzo-2-oxa-1,3- diazole)-L-cysteinyl-glycine as substrate.

Esthesioneuroblastoma: treatment of skull-base recurrence.

Thirty-nine patients with esthesioneuroblastoma are reviewed. The presentation of the tumor, symptomatology, investigation, and treatment are discussed. A recommended treatment regimen is outlined. Histologic typing is valueless in predicting tumor behavior. An illustrative and difficult case of recurrent base of skull esthesioneuroblastoma is presented. The resection performed is described, and the problem of extradural oropharyngeal communication is discussed. The solution was to use a temporalis and galeal frontalis flap. Reconstruction was with an external and intraoral prosthesis. Optimal treatment in a fresh lesion is radical surgery with or without radiation therapy. Esthesioneuroblastoma is a rare and often misdiagnosed malignant tumor of the olfactory epithelium. Originally described by Bergen et al. in 1924 as "esthesioneuroepithelioma olfactif," it was introduced into the North American literature by Schall and Lineback in 1951. Since then, fewer than 200 cases have been collected. The various terms used to describe it--olfactory esthesioneuroblastoma, esthesioneurocytoma, and olfactory neuroblastoma--all denote origin from the neural crest. The sensory nerves of smell are short bundles of fibers that originate in the olfactory bulb and pass through the cribriform plate to the olfactory area of the nasal mucosa. This mucosa is located in the most superior part of both nasal fossae. Thus the usual primary sites of occurrence include the superior nasal cavity or nasal septum, and turbinates, the ethmoid, or the cribriform plate, although an extranasal site of origin has been suggested. Symptoms are usually progressive and range from nasal obstruction or epistaxis to diplopia, ocular pain, and headaches in the more advanced disease state.(ABSTRACT TRUNCATED AT 250 WORDS)

Human fibroblast interferon for clinical trials: pharmacokinetics and tolerability in experimental animals and humans.

Human fibroblast interferon (F-interferon) purified by adsorption on controlled-pore glass was given intramuscularly to patients at daily dosages of up to 20 x 10(6) units. Serum levels of antiviral activity were low or undetectable. In contrast, reasonably high serum titers were found in patients receiving interferon prepared from leukocytes (L-interferon). Similarly, in rabbits lower serum titers were seen with F-interferon than with L-interferon. These results are at variance with those obtained earlier (V. G. Edy, A. Billiau, and P. De Somer, J. Infect. Dis. 133:A18-A21, 1976). Possible explanations for this discrepancy are discussed. The F-interferon evoked febrile reactions, delayed skin reactivity, and transitory lymphopenia in humans. Some patients developed an allergic state of the reaginic type as evidenced by a weal and flare reaction after intradermal challenge. However, these patients did not show allergic symptoms after intramuscular injections. None of the side effects was severe enough to prohibit continuation of the treatment; most of them seemed to be due to contaminants not removed by the purification method. The possibility is considered that some of the side effects, e.g., delayed skin reactivity, are sufficiently specific to justify identification of the active principals.

Degradation of levan by Actinomyces viscosus.

Actinomyces viscosus ATCC 15987 was examined for its ability to hydrolyze its own levan. Washed whole cells and an ammonium sulfate fraction from cell-free culture fluids were shown to possess levan hydrolase activity. Analyses of reaction mixtures by gel filtration and thin-layer chromatography demonstrated that the product of levan hydrolysis was free fructose. The cell-associated and extracellular enzyme preparations also hydrolyzed inulin and the levans synthesized by Aerobacter levanicum and Bacillus subtilis. Growth of A. viscosus in media supplemented with 0.1% A. viscosus levan resulted in a 33-fold increase and a 7-fold increase in the specific activities of the respective extracellular and cell-associated enzymes when compared with those from 55 mM glucose cultures. Growth in the presence of 29.2 mM sucrose resulted in a 28-fold increase and a 5-fold increase in the specific activities of the respective enzymes when compared with those from the glucose cultures. The extracellular enzyme exhibited high activity over a wide pH range, with 87 and 89% of its pH 6.0 optimum activity at pH 5.0 and 7.0, respectively. The cell-associated enzyme also exhibited optimum activity at pH 6.0, but this was decreased to 10 and 20% at pH 5.0 and 7.0, respectively. Analysis for the presence of extracellular levan during growth of A. viscosus in sucrose broths demonstrated that peak levan concentrations occurred during the mid-exponential to late-exponential phase of growth followed by a rapid decline in extracellular levan as a result of levan hydrolase activity.

Agar plate screening procedure for cyclic adenosine 3',5'-monophosphate and inhibitors of cyclic nucleotide phosphodiesterase.

A procedure is described for the semiquantitative measurement of cyclic adenosine 3',5'-monophosphate (cAMP) and detection of inhibitors of cAMP phosphodiesterase by an agar plate test. The assay organism was an adenyl cyclase-deficient mutant derived from Escherichia coli HfrH. In the presence of an acid base indicator, acid production from barbohydrate metabolism was observed as a yellow zone around filter paper disks containing cAMP. Since yellow zone formation reflects the presence of cAMP, a phosphodiesterase inhibitor can be detected indirectly by the presence of a yellow zone on assay plates from a reaction mixture of an inhibitor, phosphodiesterase, and cAMP. Three known cyclic nucleotide phosphodiesterase inhibitors were active against beef brain phosphodiesterase in this system.