The regulation of phenotype and function of human liver infiltrating lymphocytes (LIL) by in vitro culture with IL-2, IL-12 and anti-CD3 monoclonal antibodies (mAb) was investigated. The CD3+ LIL which express 50% less CD3 molecules per cell than peripheral blood T lymphocytes, exhibited a 6-fold reduction in proliferation when stimulated through the CD3 complex by anti-CD3 mAb. LIL freshly isolated or cultured in medium did not suppress MLR response, nor were they cytotoxic. However, treatment of the LIL cells with IL-2, IL-12 and anti-CD3 induced these cells to suppress autologous responding cells in MLR (ca. 70%) and to kill autologous or allogeneic cells. Low level cytotoxicity could be induced by cytokines IL-2, IL-12 or anti-CD3 alone. However, the development of optimum MLR suppression and cytotoxicity induction was dependent upon stimulation of the LIL cells through the CD3 complex. The co-expression of CD3 and CD56 on LIL was also up-regulated by anti-CD3 stimulation in the combination of IL-2 and IL-12. Most of the CD3+/CD56+ cells, also expressed CD8. After the magnetic bead separation procedure, the cytotoxic activity was found mainly in the CD3+/CD56+/CD8+ population. These results suggest that CD3+/CD56+/CD8+ cells can be expanded by stimulation through the TCR/CD3 complex in the presence of IL-2 and IL-12, which results in the suppression of autologous responding cells by a cytotoxic mechanism. The proliferative response of the CD3+/CD56+/CD8+ population was enhanced by the induction of CD1 molecules on the stimulating cells, and anti-CD1 mAb were able to block the response in a dose-dependent manner. The CD3+/CD56+/CD8+ cells were examined for cytokine production by flow cytometry. Cytokines IL-4, TNF-alpha, and IFN-gamma were produced by 91.7%, 29.2%, and 27.4% of the cells, respectively.

Antibodies, Monoclonal↗

PubMed1998

Protective efficacy of a recombinant protective antigen against Bacillus anthracis challenge and assessment of immunological markers.

The efficacy of recombinant Bacillus anthracis Protective Antigen (rPA) produced in Bacillus subtilis and formulated in Alhydrogel or MPL-TDM-CWS (Ribi adjuvant) has been tested and compared to the licensed UK human vaccine in guinea pigs challenged by the aerosol route with the Ames strain of B. anthracis. rPA combined with the Ribi adjuvant was found to be the only formulation to provide 100% protection from challenge. Analysis of immunological parameters in the individual animals revealed significant differences between the rPA/Ribi vaccine group and rPA/Alhydrogel and human vaccine groups for antigen specific lymphocyte proliferation, PA neutralisation and antigen specific IgG2 levels, but indicated no significant differences in PA-specific IgG1 levels. rPA formulated in Alhydrogel induced a mainly IgG1 response whilst the rPA/Ribi vaccine produced a predominantly IgG2 response.

Adjuvants, Immunologic↗

PubMed1998

Cytogenetic effects of energetic ions with shielding.

In order to understand the effects of shielding on the induction of biological damages by charged particles, we conducted experiments with accelerated protons (250 MeV) and iron particles (1 GeV/u). Human lymphocytes in vitro were exposed to particle beams through polyethylene with various thickness, and chromosomal aberrations were determined using FISH technique. Dose response curves for chromosome aberrations were obtained and compared for various particle types. Experimental results indicated that for a given absorbed dose at the cell, the effectiveness of protons and iron particles in the induction of chromosomal aberrations was not significantly altered by polyethylene with thickness up to 30-cm and 15-cm respectively. Comparing with gamma rays, charged particles were very effective in producing complex chromosomal damages, which may be an important mechanism in alterating functions in non dividing tissues, such as nervous systems.

Chromosome Aberrations↗

PubMed1998

Using hospital performance data in quality improvement: the Cleveland Health Quality Choice experience.

BACKGROUND: Cleveland Health Quality Choice is a regional initiative to assess hospital performance which was implemented in 1989. The project developed and validated CHOICE, a severity adjustment system that includes diagnosis-specific models for medical, surgical, and obstetrical patients which are based on clinical data abstracted from patients' medical records. METHODOLOGY: Since 1992 Cleveland Health Quality Choice has disseminated semi-annual reports that profile hospital mortality rates, lengths of stay, and cesarean section rates using the CHOICE severity adjustment models. Hospitals receive tabular and graphical representations of hospital outcomes and electronic patient-level data files that can be used to further examine outcomes in clinical subgroups. RESULTS: Four case studies illustrate how outcomes data derived from the CHOICE models led to the development of successful hospital programs to decrease lengths of stay, cesarean section rates, and hospital mortality rates. Although each case study reflected a unique approach to process improvement, several common characteristics were observed: (1) establishment of interdisciplinary process improvement teams with senior physician and nursing leadership; (2) detailed review of the process of care to identify modifiable clinical practices likely to affect outcomes; (3) development of practice guidelines based on group consensus or published recommendations that were designed to affect modifiable practices; and (4) aggressive sharing of serial data with individual practitioners. CONCLUSIONS: Although outcomes data can provide powerful insight on where to target quality improvement efforts, hospitals must identify influential and modifiable clinical practices. Such efforts are most likely to be successful if driven by interdisciplinary work groups, supported by senior clinicians and administrators, and based on locally accepted practice standards.

Adult↗

PubMed1998

An outbreak of viral gastroenteritis associated with consumption of sandwiches: implications for the control of transmission by food handlers.

Although food handlers are often implicated as the source of infection in outbreaks of food-borne viral gastroenteritis, little is known about the timing of infectivity in relation to illness. We investigated a gastroenteritis outbreak among employees of a manufacturing company and found an association (RR = 14.1, 95% CI = 2.0-97.3) between disease and eating sandwiches prepared by 6 food handlers, 1 of whom reported gastroenteritis which had subsided 4 days earlier. Norwalk-like viruses were detected by electron microscopy or reverse transcriptase-polymerase chain reaction (RT-PCR) in stool specimens from several company employees, the sick food handler whose specimen was obtained 10 days after resolution of illness, and an asymptomatic food handler. All RT-PCR product sequences were identical, suggesting a common source of infection. These data support observations from recent volunteer studies that current recommendations to exclude food handlers from work for 48-72 h after recovery from illness may not always prevent transmission of Norwalk-like viruses because virus can be shed up to 10 days after illness or while exhibiting no symptoms.

Caliciviridae Infections↗

PubMed1998

Effects of stimulus duration and intensity on simple reaction time and response force.

Previous research indicates that response force increases with stimulus intensity in simple reaction time (SRT) tasks. This result contradicts the common view that the perceptual system activates the motor system via a punctate go signal of fixed size. An elaborated view assumes that the size of the go signal depends on stimulus intensity so that more intense stimuli yield more forceful responses. In order to examine the latter hypothesis, the present experiments manipulated stimulus duration as well as intensity. Response force increased with duration even beyond a critical value of about 60 ms at which stimulus duration no longer affected SRT. In addition, increasing the duration of a stimulus also increased the duration of force output. These findings argue against models with punctate transmission of activation to the motor system. Certain continuous models and variable output models with prolonged go signals provide acceptable accounts of these effects.

Acoustic Stimulation↗

PubMed1998

On the temporal relations between memory scanning and response preparation.

Three experiments were conducted to investigate whether response processes can start before memory scanning has finished when both are required in the same task. In Experiment 1 the color of a stimulus letter determined which hand might respond, and the letter's memory set membership determined whether that response should be made or withheld. Electrophysiological data suggested that lateralized response preparation was not initiated until memory scanning finished. Experiment 2 replicated these results with a consistent stimulus-response mapping to make the scanning process easier. Experiment 3 tested for earlier response priming with a probe reaction time paradigm, and the results suggested that color information can be used to activate a response before memory scanning is finished. The results of Experiments 1-3 suggest that interference between memory scanning and response preparation precludes the concurrent operation of these processes.

Adult↗

PubMed1998

Production and purification of recombinant protective antigen and protective efficacy against Bacillus anthracis.

Recombinant protective antigen (rPA), expressed by Bacillus subtilis WB600 (pPA 101), has been purified to homogeneity and the protective efficacy against a Bacillus anthracis challenge has been investigated. rPA was fractionated from culture supernatant fluid by ammonium sulphate, followed by anion exchange chromatography using DEAE Streamline, anion-exchange chromatography on FPLC MonoQ HR 10/10 and finally, gel filtration chromatography on FPLC Superose 12 HR 10/30, to yield 7 mg rPA per litre of culture. The protective efficacy of rPA against an airborne challenge with the AMES strain of B. anthracis was determined in the presence of the adjuvants, alhydrogel and Ribi, and compared to that achieved by the current UK human vaccine in guinea pigs. rPA combined with the Ribi adjuvant was found to provide 100% protection against challenge.

Adjuvants, Immunologic↗

PubMed1998

Meter-dosed, inhaled beclomethasone attenuates bronchoalveolar oxyradical inflammation in premature infants at risk for bronchopulmonary dysplasia.

The object of this study was to examine the hypothesis that meter-dosed, inhaled beclomethasone administered to premature infants beginning at birth in a tapering dosage schedule over the first 12 days of life attenuates bronchoalveolar lining fluid oxyradical inflammation concomitant with modulation of bronchopulmonary dysplasia. The design of this study was an unblinded, uncontrolled phase I, pilot investigation of inhaled beclomethasone primarily examining safety and administration. The setting was a tertiary care neonatal intensive care unit. Intubated, premature infants were studied longitudinally to 36 weeks corrected gestational age. Meter-dosed, inhaled beclomethasone was administered in a tapering dosage schedule over the first 12 days of life. Endotracheal tube aspirates were collected on Days 2, 4, and 6 of life and assayed for various markers of bronchoalveolar lining fluid oxyradical stress. Infants were also assessed with regards to a number of relevant clinical variables and presence or absence of bronchopulmonary dysplasia at 36 weeks corrected gestational age. Although no differences in clinical outcome were apparent in comparing nine control infants with nine beclomethasone-treated infants, bronchoalveolar lining fluid from control infants exhibited evidence of apparent phospholipid peroxidation (enhanced polyunsaturated fatty acid consumption) on Day 2 of life compared to beclomethasone-treated infants. Significant differences were noted for percent arachidonic acid, total polyunsaturated fatty acids and ratio of polyunsaturated fatty acids, to saturated fatty acids. The ratio of monohydroxyl linolenic acid to native linoleic acid (a more specific marker of lipid peroxidation) as well as myeloperoxidase activity (a marker of neutrophil oxyradical stress) tended to be higher in the control group but did not achieve statistical significance for this small subject number study. No adverse reactions related to meter-dosed, inhaled beclomethasone were noted in the treatment group; most specifically no evidence of hypothalamic-pituitary-adrenal axis suppression was noted in either control or beclomethasone-treated infants. Meter-dosed, inhaled beclomethasone in the dosage schedule utilized was safe and appeared to moderate bronchoalveolar lining fluid phospholipid peroxidation. Small numbers of infants entered into the present investigation preclude comments on clinical efficacy because of the likelihood of a statistical type 2 error. However, additional investigations of inhaled beclomethasone initiated at birth in premature infants at risk for bronchopulmonary dysplasia, enrolling larger number of subjects and perhaps a higher dosage of beclomethasone, are warranted.

Administration, Inhalation↗

PubMed1998

Continuum solvent studies of the stability of RNA hairpin loops and helices.

We apply continuum solvent models to investigate the relative stability of various conformational forms for two RNA sequences, GGAC(UUCG)GUCC and GGUG(UGAA)CACC. In the first part, we compare alternate hairpin conformations to explore the reliability of these models to discriminate between different local conformations. A second part looks at the hairpin-duplex conversion for the UUCG sequence, identifying major contributors to the thermodynamics of a much large scale transition. Structures were taken as snapshots from multi-nanosecond molecular dynamics simulations computed in a consistent fashion using explicit solvent and with long-range electrostatics accounted for using the Particle-Mesh Ewald procedure. The electrostatic contribution to solvation energies were computed using both a finite-difference Poisson-Boltzmann (PB) model and a pairwise Generalized Born model; non-electrostatic contributions were estimated with a surface-area dependent term. To these solvation free energies were added the mean solute internal energies (determined from a molecular mechanics potential) and estimates of the solute entropy (from a harmonic analysis). Consistent with experiment and with earlier solvated molecular dynamics simulations, the UUCG hairpin was found to prefer conformers close to a recent NMR structure determination in preference to those from an earlier NMR study. Similarly, results for the UGAA hairpin favored an NMR-derived structure over that to be expected for a generic GNRA hairpin loop. Experimental free energies are not known for the hairpin/duplex conversion, but must be close to zero since hairpins are seen in solution and duplexes in crystals; out calculations find a value near zero and illustrate the expected interplay of solvation, salt effects and entropy in affecting this equilibrium.

Computer Simulation↗

PubMed1998

Nosocomial penicillin-resistant pneumococcal infections at a Midwestern university hospital.

We analyzed 333 isolates of Streptococcus pneumoniae from adult inpatients over a continuous 30-month period. Twenty-five percent of isolates were resistant to penicillin, and 18% of tested strains were not susceptible to ceftriaxone. For 29 (15%) of 199 evaluable patients, S pneumoniae was isolated from a culture first obtained >48 hours after admission, and chart review satisfied our case definition for nosocomial infection. S pneumoniae isolates were penicillin-resistant in 14 of 29 nosocomial and 34 of 170 community-acquired cases (odds ratio, 3.73; 95% confidence interval, 1.53-9.15; P=.01).

Community-Acquired Infections↗

PubMed1998

Contrasting levels of DNA polymorphism at the autosomal and X-linked visual color pigment loci in humans and squirrel monkeys.

The X-linked color pigment (opsin) locus is known to be highly polymorphic in the squirrel monkey and other New World monkeys. To see whether this is also the case for the autosomal (blue) opsin locus, we obtained 32 squirrel monkey and 30 human blue opsin gene sequences. No amino acid polymorphism was found in either the squirrel monkey sample or the human sample, contrary to the situation at the X-linked opsin locus. This sharp contrast in the level of polymorphism might be due to differences in gene expression between the autosomal and the X-linked loci. At the X-linked locus, heterozygote advantage can occur because, owing to X-inactivation, the two alleles in a heterozygote are expressed in different cone cells, producing two types of cone cell, whereas at the autosomal locus, heterozygote advantage cannot occur because the two alleles in a heterozygote are expressed in the same cone cells, producing only one type of cone cell (i.e., phenotypically a homozygote). From the sequence data, the levels of nucleotide diversity (pi, i.e., the number of nucleotide differences per site) are estimated: for the human sample, pi = 0.00% per nondegenerate site, 0.00% per twofold degenerate site, and 0.04% per fourfold degenerate site in the coding regions and 0.01% per site in intron 4; for the squirrel monkey sample, pi = 0.00% per nondegenerate site, 0.00% per twofold degenerate site, and 0.15% per fourfold degenerate site in the coding regions and 0.17% per site in intron 4. The blue opsin genes from the common and pygmy chimpanzees, the gorilla, the capuchin, and the howler monkey were also sequenced. Features critical to the function of the opsin are well conserved in all known mammalian sequences. However, the interhelical loops are, on average, actually more conservative than the transmembrane helical regions. In addition, these sequence data and those from some other genes indicate that the common and pygmy chimpanzees are not closely related, their divergence data being from one third to one half the date of the human-chimpanzee divergence.

Amino Acid Sequence↗

PubMed1998

Epinephrine in digital blocks: revisited.

Digital block anesthesia with epinephrine, ring technique, and digital tourniquet have been implicated in causing finger gangrene. An extensive review of the literature provided no case of finger gangrene attributed solely to the adjunctive use of epinephrine with lidocaine for digital block. By causing vasoconstriction, epinephrine complements the local analgesic by prolonging the duration of action and providing a temporary hemostatic effect. Epinephrine augmentation of digital block anesthesia was used in the treatment of 23 finger injuries without a complication.

Adolescent↗

PubMed1998

God in a teddy bear smock.

Explore the source record for details and available documents.

Child, Hospitalized↗