Influence of hemodialysis membranes on gene expression and plasma levels of interleukin-1 beta

Plasma levels of interleukin-1 beta (IL-1 beta) were measured in 10 normal subjects, in 11 nondialyzed end-stage renal failure (ESRD) patients, and in 22 hemodialysis (HD) patients. Of the HD patients, 7 were dialyzed with Cuprophan (CU), 7 with polymethylmethacrylate (PMMA), and 8 with polysulphone (PS) dialyzers. In normal controls, nondialyzed ESRD patients, and HD equipped with CU, PAMM, and PS dialyzers, plasma levels of IL-1 beta were 10.73 +/- 5.24 pg/ml, 9.97 +/- 3.61 pg/ml, 13.17 +/- 4.04 pg/ml, 15.16 +/- 6.16 pg/ml, and 13.96 +/- 5.47 pg/ml, respectively. There were no statistically significant differences among the groups (p > or = 0.05). In contrast, the gene expression of IL-1 beta for peripheral blood mononuclear cells (PBMC) by in situ hybridization showed differences among the groups. The gene for IL-1 beta for PBMC appears in HD equipped with different membranes, but not in cases of nondialyzed uremic patients and normal subjects. With computer imaging analysis, we carried out quantitative analysis of cells in in situ hybridization with an area of positive spots to an area of total cells. In HD with CU, PMMA, and PS, the results were 10.64 +/- 1.07, 3.34 +/- 0.74, and 3.27 +/- 0.64%, respectively. The levels of IL-1 beta gene expression in CU were higher than that in PMMA or PS. There were statistically significant differences (p < or = 0.001) between CU and PMMA or PS and no significant difference between the PMMA and PS (p > or = 0.05). We suggest measuring the gene expression of cytokines for PBMC and which may be better than measuring cytokine levels only for investigating the blood compatibility of dialyzers, which may help in understanding chronic complications of the dialysis procedure.

Genetic immunization against herpes simplex virus. Protection is mediated by CD4+ T lymphocytes

Plasmid DNA encoding proteins represent a convenient novel approach to vaccination. We have investigated this "genetic immunization" approach as a means to protect against herpes simplex virus (HSV) infection using a mouse zosteriform model that mimics several aspects of reactivated HSV infection of humans. After i.m. immunization with plasmid DNA-encoding glycoprotein B (gB), (pc-gB), 80% of BALB/c mice were completely protected and lesions were delayed in the remaining animals. Upon pc-gB vaccination, the animals developed both gB- and HSV-specific IgG Ab response and the isotype examination revealed a predominance of IgG2a. These mice also have low levels (1/16) of HSV-neutralizing Abs. Immune splenocytes obtained from pc-gB-immunized mice, when restimulated in vitro with HSV resulted in production of type 1 cytokines. Evidence for CD(8+)-mediated cytotoxic T lymphocyte response was equivocal. Protection could be adoptively transferred to nude mice recipients by CD4+ T cells from pc-gB-immunized mice but not by CD8+ T cells. Our results demonstrate that genetic immunization is a potent means of inducing protection against HSV and that the mechanism of immunity responsible for clearing virus from cutaneous sites is principally by CD4+ T cells. It is likely that these cells are Th1 cells because type 1 cytokines were the major cytokines detected upon in vitro Ag stimulation.

Genetic immunization against herpes simplex virus. Protection is mediated by CD4+ T lymphocytes

Plasmid DNA encoding proteins represent a convenient novel approach to vaccination. We have investigated this "genetic immunization" approach as a means to protect against herpes simplex virus (HSV) infection using a mouse zosteriform model that mimics several aspects of reactivated HSV infection of humans. After i.m. immunization with plasmid DNA-encoding glycoprotein B (gB), (pc-gB), 80% of BALB/c mice were completely protected and lesions were delayed in the remaining animals. Upon pc-gB vaccination, the animals developed both gB- and HSV-specific IgG Ab response and the isotype examination revealed a predominance of IgG2a. These mice also have low levels (1/16) of HSV-neutralizing Abs. Immune splenocytes obtained from pc-gB-immunized mice, when restimulated in vitro with HSV resulted in production of type 1 cytokines. Evidence for CD(8+)-mediated cytotoxic T lymphocyte response was equivocal. Protection could be adoptively transferred to nude mice recipients by CD4+ T cells from pc-gB-immunized mice but not by CD8+ T cells. Our results demonstrate that genetic immunization is a potent means of inducing protection against HSV and that the mechanism of immunity responsible for clearing virus from cutaneous sites is principally by CD4+ T cells. It is likely that these cells are Th1 cells because type 1 cytokines were the major cytokines detected upon in vitro Ag stimulation.

In vivo marginal adaptation of cast crowns luted with different cements

Large marginal crown discrepancies are deleterious. Although previous studies have examined casting seating in vitro, few have evaluated the effects of different luting cements on in vivo seating. Hence this in vivo study compared marginal discrepancies created by different cements on cast crowns. Tooth preparations were completed according to acceptable procedures on previously intact human molars that were severely periodontally compromised and scheduled for extraction. Castings were made by conventional techniques. The castings were randomly assigned to the following luting agents: zinc phosphate cement, resin-modified glass-ionomer cement, and the same resin-modified glass-ionomer cement with a dentinal bonding agent. After 6 months the teeth were carefully extracted, embedded, and sectioned, and vertical and horizontal discrepancies were measured. Analysis of variance revealed that all cements resulted in similar discrepancies. Vertical discrepancies were considerably greater than horizontal discrepancies, and the distributions of marginal discrepancies were skewed towards upper ranges.

Antiviral action of interferon-beta on Newcastle disease virus: selectivity to the hemagglutinin-neuraminidase gene expression

Interferon-beta (IFN-beta) strongly inhibited the expression of the hemagglutinin-neuraminidase (HN) gene of Newcastle disease virus (NDV), a paramyxovirus, in HeLa cells under the conditions where it did not affect the expression of the four upstream genes encoding the nucleocapsid protein, phosphoprotein, membrane protein and fusion protein. Even the downstream gene, encoding the large protein as well as the genome replication, appeared to be less susceptible to IFN-beta than the HN gene. This selective action of IFN-beta did not appear to be attributable to its well characterized antiviral mechanisms such as acceleration of RNA decay and translation inhibition. No similar down-regulation of a particular gene expression was found with another paramyxovirus, Sendai virus, or with a rhabdovirus, vesicular stomatitis virus, or seems to have been reported previously with any negative-strand RNA viruses. This new effect of IFN-beta thus suggests gene expression mechanism unique to NDV and may further lead to the discovery of a novel biochemical effect of IFN-beta.

[Relationship between elevated plasma endothelin-1 level and renal function in patients with diabetic nephropathy]

Plasma endothelin-1 (ET-1) level was measured with radioimmunoassay in 33 normal subjects and 92 patients with different stages of diabetic nephropathy, consisting of 35 cases of diabetes mellitus with normal urinary albumin excretion (DM), 22 cases of incipient diabetic nephropathy (IDN), 22 cases of overt diabetic nephropathy (ODN), 8 cases with azotemia (DNa) and 5 cases with uremia (DNu). The results showed that plasma ET-1 levels in DNa and DNu groups (30.24 +/- 1.93 ng/L and 36.38 +/- 3.62 ng/L respectively) were significantly higher than those in other groups (P < 0.05); ET-1 level in ODN group (20.50 +/- 0.93 ng/L) was significantly higher than those in DM and IDN groups (P < 0.001); ET-1 level in IDN group was also significantly higher than that in DM group (17.79 +/- 0.74 vs. 15.06 +/- 0.63 ng/L, P < 0.01); All the above values were significantly higher than that in normal subjects (7.08 +/- 0.22 ng/L) (P < 0.001). There was significant positive correlation between ET-1 level and HbA1c, systolic pressure, diastolic pressure, blood urea nitrogen, serum creatine, uAER and a significant negative correlation between ET-1 level and glomerular filtration rate. It is shown that progressive elevation of plasma ET-1 level is closely related with different stages of renal function impairment, suggesting strongly the role of ET-1 in the development and progression of diabetic nephropathy.

[Treatment and prognosis of stage II testicular seminoma]

Sixty-five patients with stage II testicular seminoma treated from 1960 through 1990 were reviewed. According to Royal Marsden Hospital staging, there were 11 stage IIA, 13 stage IIB, and 41 stage IIC. Thirty Patients were treated with combination of radiotherapy and chemotherapy, 11 chemotherapy alone, 24 rediotherapy alone. The overall 5-year survival rate was 75.6%, with 100% for stage IIA, 92.3% for stage IIB and 62.9% for stage IIC. The differences were statistically significant. In stage IIC patients, there was no significant difference between those tumors > 10cm and < 10cm in diameter. Of the 41 IIC cases, 4 were treated with chemotherapy, 15 were treated with whole abdominal rediation, 22 with paraaortic and ipsilateral pelvic radiation. The 5-year survival rate was 91.7% and 51.2%, respectively. These differences was statistically significant. We recommand that stage IIC disease should be treated primarily with whole abdominal radiation. Regardless of the stage of the disease, prophylactic mediastinal irradiation did not influence the survival nor the relapse rate and may therefore be omitted.

An evaluation of numerical integration algorithms for the estimation of the area under the curve (AUC) in pharmacokinetic studies

Six numerical integration algorithms based on linear and log trapezoidal methods as well as four cubic-spline methods were proposed for estimation of area under the curve (AUC). These six different algorithms were implemented using IMSL/IDL command language and evaluated using data simulated under five different dosing conditions and two different sampling conditions. Comparisons between AUC estimations using these six different algorithms and the theoretical results were made in terms of both overall AUC values and the superimposability of the concentration-time profiles. In well designed studies with ample data points, the algorithm based on IMSL/IDL function CSSHAPE with concavity preservation gave the best performance. In contrast, when the frequency of blood collection was limited, the algorithm based on the log trapezoidal rule proved to be stable with reasonable accuracy, and is recommended as the practical method for numerical interpolation and integration in pharmacokinetic studies. Algorithms based on the combination of the log trapezoidal rule and cubic-spline methods using IMSL/IDL function CSSHAPE can be developed to enhance overall performance.

Induction of protective immunity against herpes simplex virus with DNA encoding the immediate early protein ICP 27

Using a mouse zosteriform model that mimics human herpes simplex virus (HSV) infection in several aspects, the effectiveness of plasmid DNA encoding the immediate early protein ICP 27 was evaluated as a vaccine. Animals were immunized intramuscularly twice with DNA, then either challenged with virus or killed, and the nature of the immune response induced was measured. After intramuscular injection with plasmid DNA encoding ICP 27 (pc-ICP 27), solid protection was evident in 70-80% of mice and the lesions were delayed in the remaining animals. Immune splenocytes obtained from pc-ICP 27 immune mice showed HSV-specific lymphoproliferation, MHC-class I restricted cytotoxic T-lymphocyte (CTL) activity, and type 1 cytokine production. These animals also exhibited delayed-type hypersensitivity (DTH) reactions. Adoptive transfer studies conducted on syngeneic nude mice revealed that those recipients of immune CD4+ T cells, but not CD8+ T cells, were protected from subsequent HSV-1 (strain 17) challenge. Thus pc-ICP 27 DNA immunization protected the mice principally by CD4+ T cells and it is likely that these cells were Th-1 type because only type 1 cytokines were detectable after in vitro antigen stimulation. Our results indicate the potential value of DNA encoding nonstructural viral proteins as vaccines against HSV.

Effect of current magnitude and drug concentration on iontophoretic delivery of octreotide acetate (Sandostatin) in the rabbit

The effect of current magnitude and drug concentration on transdermal iontophoretic delivery of octreotide acetate (Sandostatin) was examined in the rabbit. Plasma samples were collected over 24 hours and octreotide concentrations were determined by a radioimmunoassay. Without an electrical current, negligible plasma concentrations of octreotide were obtained. Following initiation of iontophoresis, plasma concentrations of octreotide increased rapidly, although did not sustain at a plateau level during the dosing period. Octreotide concentrations declined rapidly after removal of the device. Increasing the electrical current from 50 microA/cm2 to 150 microA/cm2 yielded a proportional increase in the delivery. Increasing the drug concentration in the device from 2.5 mg/mL to 5 mg/mL resulted in approximately proportional increase in plasma octreotide concentrations; however, further increase in plasma concentrations was not observed for drug concentrations beyond 5 mg/mL. Iontophoretic delivery at the conditions which yielded the highest octreotide concentrations in this study (5 mg/mL solution at 150 microA/cm2 for 8 hours) yielded an apparent bioavailability (which represents an underestimate of the absolute bioavailability determined when the patches are run to exhaustion) of approximately 8%.

Lysis of porcine trophoblast cells by endometrial natural killer-like effector cells in vitro does not require interleukin-2

Cells with cytotoxic activity against the cell line K562 and expressing perforin have been demonstrated in endometrial cells isolated from pigs early in pregnancy. This study was designed to determine whether porcine trophoblast cells were susceptible to these endometrial effector cells in vitro. Pregnant gilts (n = 8) were slaughtered between Days 17 and 20 of gestation. Immediately after slaughter, both the endometrial effector cells and trophoblast cells were isolated enzymatically from each animal. Enzymatically dispersed endometrial cells were further fractionated by size at unit gravity, whereas trophoblast cells were enriched by discontinuous density centrifugation on Percoll. Cytolytic activity was evaluated against Na2 51CrO4-labeled trophoblast and K562 cells. Comparison was made between freshly prepared and interleukin-2 (IL-2)-stimulated effector cells. The effect of prostaglandin E2 (PGE2) was tested by including it directly in the 51Cr-release assay. The results indicated that porcine trophoblast cells, like K562 cells, could be recognized and directly lysed by endometrial effector cells. Preculture of effector cells with IL-2 was not required for target lysis but enhanced their cytolytic activity against both trophoblast and K562 targets. In contrast, PGE2 exhibited highly suppressive effects on the cytotoxic activity of both freshly isolated and IL-2-stimulated endometrial effector cells. Conjugate assays demonstrated the binding of trophoblast and K562 targets by effector cells of similar morphology. Cold-target inhibition assays suggested that the effectors in porcine endometrial cell preparations that killed trophoblast and K562 cells were the same NK cell-like population.

Saturated molecular map of the rice genome based on an interspecific backcross population

A molecular map has been constructed for the rice genome comprised of 726 markers (mainly restriction fragment length polymorphisms; RFLPs). The mapping population was derived from a backcross between cultivated rice, Oryza sativa, and its wild African relative, Oryza longistaminata. The very high level of polymorphism between these species, combined with the use of polymerase chain reaction-amplified cDNA libraries, contributed to mapping efficiency. A subset of the probes used in this study was previously used to construct an RFLP map derived from an inter subspecific cross, providing a basis for comparison of the two maps and of the relative mapping efficiencies in the two crosses. In addition to the previously described PstI genomic rice library, three cDNA libraries from rice (Oryza), oat (Avena) and barley (Hordeum) were used in this mapping project. Levels of polymorphism detected by each and the frequency of identifying heterologous sequences for use in rice mapping are discussed. Though strong reproductive barriers isolate O. sativa from O. longistaminata, the percentage of markers showing distorted segregation in this backcross population was not significantly different than that observed in an intraspecific F2 population previously used for mapping. The map contains 1491 cM with an average interval size of 4.0 cM on the framework map, and 2.0 cM overall. A total of 238 markers from the previously described PstI genomic rice library, 250 markers from a cDNA library of rice (Oryza), 112 cDNA markers from oat (Avena), and 20 cDNA markers from a barley (Hordeum) library, two genomic clones from maize (Zea), 11 microsatellite markers, three telomere markers, eleven isozymes, 26 cloned genes, six RAPD, and 47 mutant phenotypes were used in this mapping project. Applications of a molecular map for plant improvement are discussed.

Pharmacokinetics of intranasally-administered dihydroergotamine in the rat

Intranasal dosing of dihydroergotamine (DHE) allows convenient self-administration and provides an alternate route of administration for the treatment of migraine in addition to the existing parenteral dosage forms. In this study, the pharmacokinetics of 3H-DHE were investigated following intravenous and intranasal dosing (0.343 mg DHE/animal) in the rat. Intranasal administration of DHE resulted in rapid absorption. The extent of absorption of the radiolabeled dose was approximately 45%-60%. Absolute bioavailability of the parent drug was 35%-40%, as determined by deconvolution and by the ratios of AUC0-infinity following intranasal and intravenous dosing. Due to the limited capacity of the nostrils, approximately half of the intranasal dose was swallowed into the gastrointestinal tract. Biliary excretion was found to be the predominant pathway of radioactivity excretion following both routes of administration. The results from this study suggest that intranasal administration provides a viable means of delivering DHE into the systemic circulation.

Luting cement-metal surface physicochemical interactions on film thickness

Low film thickness is critical to the clinical success of cemented castings. This study investigated the effect of luting agent-metal physico-chemical surface interactions on film thicknesses of representative luting agents. Control group luting agents were placed between two glass plates, as described by American Dental Association specifications 8, 61, and 66, and test group luting agents were positioned between glass and metal plates. The materials selected were zinc phosphate cement, polycarboxylate cement, glass ionomer cement, glass ionomer-composite resin hybrid cement and a resinous cement, with a type III gold alloy, a noble metal ceramic alloy, and a base metal ceramic alloy. A two-way analysis of variance and follow-up tests were done. The effects of the type of metal surface, type of cement, and their statistical interaction significantly affected film thickness (p < 0.0001). The type of cement had a greater affect on film thickness than the type of metal. A glass ionomer cement produced lower overall film thicknesses than other cement types, and a noble metal ceramic alloy created lower overall film thicknesses than other types of metal. American Dental Association specifications for cement film thickness did not accurately reflect normal cement use.

Diminished luminal release of esophageal epidermal growth factor in patients with reflux esophagitis

OBJECTIVES

It has recently been demonstrated that human esophageal mucosa, containing numerous submucosal mucous glands, has the ability to elaborate significant amounts of esophageal epidermal growth factor (eEGF). Because of its role in the maintenance of the integrity of the esophageal mucosa, we elected to study the rate of secretion of eEGF in patients with reflux esophagitis (RE), compared with controls, using our newly developed esophageal perfusion model.

METHODS

Fourteen healthy asymptomatic volunteers and 14 patients with endoscopically confirmed esophagitis underwent esophageal perfusion with saline, HCl (0.01 M, pH 2.1) HCl/pepsin (0.5 mg/ml of HCl), and ending NaCl solution during four consecutive 8-min perfusion periods. All perfusates were assayed for EGF by RIA (Amersham). Results are expressed as mean +/- SEM. Student's t test was used for statistical analysis.

RESULTS

The basal rate of luminal EGF release in patients with RE was 3.78 +/- 0.29 ng/min. This value significantly declined (2.27 +/- 0.27 ng/min; p < 0.001) during mucosal exposure to HCl but was significantly enhanced when the HCl perfusing solution was supplemented with pepsin (4.20 +/- 0.29; p < 0.001 vs. HCl). Introduction of saline during the last perfusion period maintained a rate of luminal EGF release similar to that observed during the initial esophageal perfusion with saline. Luminal release of EGF in patients with RE was significantly lower, compared with corresponding values recorded in controls during perfusion with saline (3.78 +/- 0.29 vs. 14.1 +/- 1.25 ng/min; p < 0.00001), with HCl (2.27 +/- 0.27 vs. 5.95 ng/min; p < 0.0001), with HCl/pepsin solution (4.2 +/- 0.29 vs. 11.7 +/- 1.88 ng/min; p < 0.0001), and during the final perfusion period with saline (3.73 +/- 0.25 vs. 15.1 +/- 1.1 ng/min; p < 0.00001). Therefore, the rate of luminal EGF release in controls was 4-fold, 3-fold, 3-fold, and 4-fold higher than that of patients with RE during perfusion with initial saline, HCl, HCl/pepsin and final saline, respectively.

CONCLUSIONS

1) Decreased esophageal EGF in patients with RE may facilitate the development or delay the healing of mucosal injury. 2) Depletion of EGF from the mucus layer covering the epithelium under the impact of refluxed luminal acid/pepsin may be considered as one of the potential underlying mechanisms leading to damage of the esophageal mucosa during gastroesophageal reflux episodes.

Depressed [Ca2+]i responses to isoproterenol and cAMP in isolated cardiomyocytes from experimental diabetic rats

Experimentally, diabetic rat hearts are characterized by diminished responses to beta-adrenergic stimulation. Among the aberrant responses are diminished beta-adrenoceptor number and depressed contractile protein activity. In this study, intracellular Ca2+ concentration ([Ca2+]i) was determined by microfluorescence in response to beta-adrenergic stimulation to understand the basis for the changes in the beta-adrenergic pathway in diabetic myocardium. In quiescent myocytes, isoproterenol caused a decrease in [Ca2+]i, which was blocked by timolol and thapsigargin. This suggests that the beta-agonist-induced [Ca2+]i changes are mediated, in part, by sarcoplasmic reticulum Ca-adenosinetriphosphatase. Diabetic myocytes showed a blunted response to isoproterenol, which was reversed by insulin treatment. In electrically stimulated myocytes, isoproterenol and 8-bromo-adenosine 3',5'-cyclic monophosphate (cAMP) increased [Ca2+]i and contraction in a concentration-dependent manner. Electrically stimulated diabetic myocytes demonstrated a depressed maximum [Ca2+]i response to isoproterenol and 8-bromo-cAMP without a change in sensitivity. These data suggest that in addition to alterations in beta-adrenoceptor function there are postreceptor defects in diabetic myocardium that may impair the regulation of [Ca2+]i in diabetic myocardium.

An ultra-sensitive electrochemical enzyme immunoassay for thyroid stimulating hormone in human serum

A sensitive heterogeneous electrochemical enzyme immunoassay has been developed for thyroid stimulating hormone (TSH) by modifying a commercially available two-site immunoenzymometric assay. p-Aminophenyl phosphate (PAPP) was used as the substrate of alkaline phosphatase, and hydrolysed to p-aminophenol (PAP). The amount of PAP produced from the assay was proportional to the amount of TSH in the sample. Detection of PAP was done by oxidative amperometry in a flow injection system. The working electrode was a glassy carbon electrode whose potential was held at +325 mV (vs Ag/AgCl). The amperometric detection of PAP required only 1 microliter of sample (the range of linearity: 50.0 fmol-100 pmol PAP, the limit of detection: 10.9 fmol PAP). Intra-assay precision over the assay range of linearity (0.02-60 mIU l-1 or 0.02-60 pIU TSH) showed a maximum RSD of 8.0%, and a low detection limit of 0.01 mIU l-1 or 0.01 pIU TSH. The study also indicates that this two-site electrochemical enzyme immunoassay correlates well with the Bio-Rad's immunoradiometric assay currently used in our medical center (r = 0.992, slope = 1.53, n = 43) and a highly sensitive immunochemiluminometric assay in the Nichols Institute (r = 0.986, slope = 0.499, n = 23).