Mite-related bacterial antigens stimulate inflammatory cells in rosacea

BACKGROUND

Patients with papulopustular rosacea have a higher density of Demodex folliculorum mites on their faces than normal subjects but the role, if any, of their mites in initiating inflammation is disputed. Selective antibiotics are effective in reducing the inflammatory changes of papulopustular rosacea, but their mode of action is unknown.

OBJECTIVES

To investigate whether a D. folliculorum-related bacterium was capable of expressing antigens that could stimulate an inflammatory immune response in patients with rosacea.

METHODS

A bacterium (Bacillus oleronius) was isolated from a D. folliculorum mite extracted from the face of a patient with papulopustular rosacea, and was investigated further.

RESULTS

This bacterium produced antigens capable of stimulating peripheral blood mononuclear cells proliferation in 16 of 22 (73%) patients with rosacea but only five of 17 (29%) control subjects (P = 0.0105). This antigenic preparation was fractionated into 70 subfractions and the proteins in each fraction were visualized by sodium dodecyl sulphate-polyacrylamide gel electrophoresis. Western blot analysis revealed the presence of two antigenic proteins of size 62 and 83 kDa in fractions when probing with sera from patients with rosacea. No immunoreactivity to these proteins was recorded when probing with sera from control patients. Two-dimensional electrophoretic separation was used to isolate these proteins and matrix-assisted laser desorption/ionization time-of-flight analysis was employed to identify the relevant peptides. The 62-kDa immunoreactive protein shared amino acid sequence homology with an enzyme involved in carbohydrate metabolism and signal transduction while the 83-kDa protein was similar to bacterial heat shock proteins.

CONCLUSIONS

Antigenic proteins related to a bacterium (B. oleronius), isolated from a D. folliculorum mite, have the potential to stimulate an inflammatory response in patients with papulopustular rosacea.

Does an integrated care pathway enhance the management of diabetic ketoacidosis?

AIMS

Integrated Care Pathways (ICPs) are management plans that indicate the sequence and timing of the optimal treatment for individuals with a given disorder. The treatment of diabetic ketoacidosis (DKA) before and after the implementation of an ICP in a teaching hospital was examined.

METHODS

Twenty-seven episodes of DKA were identified during the 13-month control period and 22 in the 13 months following implementation of the ICP. Case notes were reviewed and relevant clinical data extracted.

RESULTS

The introduction of the ICP was associated with a reduction in the time taken to initiate intravenous fluid [45.0 (5-225) min to 37.5 (0-135) min; P = 0.01]. Time taken to initiate insulin infusion was also reduced [60.0 (5-755) min to 37.5 (0-175) min; P = 0.02]. The proportion of patients commenced on intravenous insulin within 60 min increased from 48 to 77% (P = 0.04). In addition, there was a reduction in the prescription of antibiotics (48-18%; P = 0.028) and low molecular weight heparin (59-5%; P < 0.001). Length of stay was not affected.

CONCLUSION

The ICP significantly improved key areas in the management of DKA, although there remains room for further improvements.

Effect of hyperbaric oxygen on oxygen uptake and measurements in the blood and tissues in a normobaric environment

OBJECTIVE

To examine venous partial pressure of oxygen (PvO(2)), transcutaneous oxygen tension (tcPO(2)), and VO(2)MAX in a normobaric environment after a single hyperbaric oxygen (HBO(2)) treatment.

METHODS

This was a prospective study of conditions after the intervention compared with baseline. The participants were 10 moderately trained (VO(2)MAX = 57.6 ml/kg/min) men. Two HBO(2) treatments consisting of breathing 95% oxygen at 2.5 atmospheres absolute (ATA) for 90 minutes were administered on non-consecutive days. Baseline testing included measures of VO(2)MAX, tcPO(2), and anthropometry. At 6.0 (1.0) minutes after the first HBO(2) treatment, a VO(2)MAX test was performed. After the second HBO(2) treatment, leg and chest tcPO(2) and PvO(2) were monitored for 60 minutes.

RESULTS

VO(2)MAX, running time, and peak blood lactate were not altered after the HBO(2) treatment. Leg tcPO(2) was lower (p = 0.003) and chest tcPO(2) was unchanged after the HBO(2) treatment compared with baseline values. PvO(2) was significantly (p<0.001) lower in the first three minutes after treatment than subsequent values, but no other differences were found.

CONCLUSIONS

A single HBO(2) treatment at 2.5 ATA for 90 minutes does not raise PvO(2), tcPO(2), or VO(2)MAX in a normobaric, normoxic environment.

Correlation of photosensitizer delivery to lipoproteins and efficacy in tumor and arthritis mouse models; comparison of lipid-based and Pluronic P123 formulations

PURPOSE

The purpose of this study was the use of animal models to demonstrate the importance of drug delivery (verteporfin) to plasma lipoproteins in order to attain efficacy of photodynamic therapy (PDT) in vivo.

METHODS

Photosensitizers appropriately formulated in various vehicles such as pluronics and lipid-based systems were compared to delivery of the drug in DMSO in two in vivo systems. The first was a tumor model using male DBA/2 mice inoculated intradermally with M1 rhabdomyosarcoma cells and in the second, arthritis in the MRL -lpr mouse strain was enhanced by two intradermal injections of complete Freunds adjunct.

RESULTS

Those formulations in which the drug was in a monomeric form were better able to transfer drug to lipoproteins, which in turn led to superior PDT in vivo.

CONCLUSIONS

The ability to introduce drug in monomeric form into the circulation correlates well with efficacy of photosensitizer formulations in mouse arthritis and tumor models.

Systematic distortions of auditory space perception following prolonged exposure to broadband noise

Perceptual distortions referred to as aftereffects may arise following exposure to an adapting sensory stimulus. The study of aftereffects has a long and distinguished history [Kohler and Wallach, Proc. Am. Philos. Soc. 88, 269-359 (1944)] and a range of aftereffects have been well described in sensory modalities such as the visual system [Barlow, in Vision: Coding and Efficiency (Cambridge University Press, Cambridge, 1990)]. In the visual system these effects have been interpreted as evidence for a population of cells or channels specific for certain features of a stimulus. However there has been relatively little work examining auditory aftereffects, particularly in respect of spatial location. In this study we have examined the effects of a stationary adapting noise stimulus on the subsequent auditory localization in the vicinity of the adapting stimulus. All human subjects in this study were trained to localize short bursts of noise in a darkened anechoic environment. Adaptation was achieved by presenting 4 min of continuous noise at the start of each block of trials and was maintained by a further 15-s noise burst between each trial. The adapting stimulus was located either directly in front of the subject or 30 degrees to the right of the midline. Subjects were required to determine the location of noise burst stimuli (150 ms) in the proximity of the adapting stimulus following each interstimulus period of adaptation. Results demonstrated that following adaptation there was a general radial displacement of perceived sound sources away from the location of the adapting stimulus. These data are more consistent with a channel-based or place-based process of sound localization rather than a simple level-based adaptation model. A simple "distribution shift" model that assumes an array of overlapping spatial channels is advanced to explain the psychophysical data.

The localisation of spectrally restricted sounds by human listeners

The two principal binaural cues to sound location are interaural time differences (ITDs), which are thought to be dominant at low frequencies, and interaural level differences (ILDs), which are thought to dominate at mid to high frequencies. The outer ear also filters the sound in a location dependent manner and provides spectral cues to location. In these experiments we have examined the relative contribution of these cues to the auditory localisation performance by humans. Six subjects localised sounds by pointing their face toward the perceived location of stimuli presented in complete darkness in an anechoic chamber. Control stimuli were spectrally flat (400 Hz to 16 kHz), while the relative contribution of location cues in the low frequency channels was determined using noise high passed at 2 kHz and in the high frequency channels using stimuli low passed at 2 kHz. The removal of frequencies below 2 kHz had little effect on either the pattern of systematic errors or the distribution of localisation estimates with the exception of an increase in the size of the standard deviations associated with a few rear locations. This suggests considerable redundancy in the auditory localisation information contained within a broadband sound. In contrast, restricting the target spectrum to frequencies below 2 kHz resulted in a large increase in the cone-of-confusion errors as well as a subject dependent biasing of the front-to-back or back-to-front confusions. These biases and the reduction in localisation accuracy for high pass stimuli at some posterior locations are consistent with a contribution of spectral information at low frequencies.

A critical evaluation of hepatitis C testing of cadaveric corneal donors

PURPOSE

Enzyme immunoassays (EIAs) for hepatitis C virus (HCV) antibodies used to screen corneal donors are optimized for testing premortem sera. This study evaluated their efficiency when screening cadaveric sera.

METHODS

Abbott HCV EIA 2.0 was used to rescreen 101 cadaveric sera, 70 of which had tested positive and 31 negative by EIA 1.0. Matrix-HCV recombinant immunoblot assay was used as a reference standard. Antibody titers and reactivities were compared in premortem and cadaveric sera. Selected sera from confirmed seropositive donors were screened for virus by polymerase chain reaction (PCR).

RESULTS

HCV EIA 2.0 was 100% sensitive and 92.7% specific. EIA and Matrix-HCV gave similar end-point titers with pre- and postmortem sera. Viral RNA was detected in only three of 15 sera from seropositive donors.

CONCLUSIONS

EIA 2.0 and Matrix-HCV efficiently screen cadaveric sera. However, HCV seropositivity does not necessarily indicate the presence of viral genomes in sera and tissues.

Isolation and genetic mapping of two novel members of the murine Wnt gene family, Wnt11 and Wnt12, and the mapping of Wnt5a and Wnt7a

The murine Wnt genes are implicated in the control of a variety of developmental processes. Using a PCR-based approach, we have isolated two novel members of the murine Wnt gene family, Wnt11 and Wnt12. These cDNAs display an amino acid sequence identity of between 38 and 49% with all other murine Wnts over the regions that we have isolated. In addition, two previously described Wnt genes, Wnt5a and Wnt7a, were detected in RT-PCR products. Interspecific crosses were used to demonstrate close linkage between Wnt12 and Wnt1 on Chromosome (Chr) 15. Wnt7a was mapped to mouse Chr 6, Wnt5a to the centromeric region of Chr 14, and Wnt11 to Chr7.

Sequencing of chromosome I of Saccharomyces cerevisiae: analysis of the 42 kbp SPO7-CENI-CDC15 region

Determination of the DNA sequence and preliminary functional analysis of a 42 kbp centromeric section of chromosome I have been completed. The section spans the SPO7-CEN1-CDC15 loci and contains 19 open reading frames (ORFs). They include an apparently inactive Ty1 retrotransposon and eight new ORFs with no known homologs or function. The remaining ten genes have been previously characterized since this part of the yeast genome has been studied in an unusually intensive manner. Our directed sequencing allows a complete ordering of the region.

Transmission of hepatitis C by kidney transplantation--the risks

The use of cadaveric organ donors with positive serologic tests for hepatitis C (HCV) has caused considerable debate. We have reviewed the clinical course of 43 EIA1 HCV-negative recipients who received kidney transplants from EIA1 HCV-positive donors (Study). We have attempted to define the rate of HCV-RNA transmission and to determine the frequency of HCV disease transmission as determined by abnormalities in liver function tests. Viral transmission was assessed using serologic assays for HCV antibody formation (EIA1, EIA2, and Matrix--an automated multiple antigen immunoblot assay) and with PCR testing for the presence of HCV-RNA on recipient sera. Liver function was followed longitudinally in the Study patients and compared with a group of 103 kidney recipients of organs from EIA1 HCV-negative donors (Control). Of the Study patients, 56% became PCR-positive for HCV-RNA, suggesting the transmission of HCV-RNA from the HCV-positive donor. Interpretation of serologic tests for HCV was complex. Currently available first (EIA1) and second (EIA2) generation serologic assays were always negative. The multiple antigen immunoblots assay (Matrix) had a high positive predictive value (93%) for the presence of HCV-RNA transmission, but one-third of Matrix-negative Study patients were PCR-positive (sensitivity = 66%). Currently, only 38% of recipients have HCV-RNA, suggesting that the virus may have been cleared by one-third of Study recipients who had circulating virus. Traditional tests of liver function (ALT, AST, AP, and GGT) were of limited use in predicting HCV-RNA transmission. Average AST, AP, and GGT were similar in the two groups. Average ALT was increased (93 I/U and 47 I/U) in Study and Control patients, respectively, but this difference was not significant. Episodes of abnormal liver function (ALT 60-99 IU for > or = 14 days) occurred in 22% of Study and 10% of Control patients (P = NS) and lasted longer in Study compared with Control patients (301 vs. 138 days; P < 0.02). Hepatitis (ALT > or = 100 IU for > 14 days) occurred with an equal frequency (6.5%) in both groups. The presence of HCV-RNA did not predict episodes of abnormal liver function. Fulminant hepatitis or rapidly progressive cirrhosis did not occur in the recipients of organs from HCV-positive donors. These data demonstrate a high efficiency of transfer of HCV-RNA by kidney transplantation from an HCV-positive donor to an HCV-negative recipient. A majority of the patients have asymptomatic HCV infection.(ABSTRACT TRUNCATED AT 400 WORDS)

SKN1 and KRE6 define a pair of functional homologs encoding putative membrane proteins involved in beta-glucan synthesis

KRE6 encodes a predicted type II membrane protein which, when disrupted, results in a slowly growing, killer toxin-resistant mutant possessing half the normal level of a structurally wild-type cell wall (1-->6)-beta-glucan (T. Roemer and H. Bussey, Proc. Natl. Acad. Sci. USA 88:11295-11299, 1991). The mutant phenotype and structure of the KRE6 gene product, Kre6p, suggest that it may be a beta-glucan synthase component, implying that (1-->6)-beta-glucan synthesis in Saccharomyces cerevisiae is functionally redundant. To examine this possibility, we screened a multicopy genomic library for suppression of both the slow-growth and killer resistance phenotypes of a kre6 mutant and identified SKN1, which encodes a protein sharing 66% overall identity to Kre6p. SKN1 suppresses kre6 null alleles in a dose-dependent manner, though disruption of the SKN1 locus has no effect on killer sensitivity, growth, or (1-->6)-beta-glucan levels. skn1 kre6 double disruptants, however, showed a dramatic reduction in both (1-->6)-beta-glucan levels and growth rate compared with either single disruptant. Moreover, the residual (1-->6)-beta-glucan polymer in skn1 kre6 double mutants is smaller in size and altered in structure. Since single disruptions of these genes lead to structurally wild-type (1-->6)-beta-glucan polymers, Kre6p and Skn1p appear to function independently, possibly in parallel, in (1-->6)-beta-glucan biosynthesis.

Physical localization of yeast CYS3, a gene whose product resembles the rat gamma-cystathionase and Escherichia coli cystathionine gamma-synthase enzymes

We have cloned, sequenced and physically mapped the CYS3 gene of Saccharomyces cerevisiae. This gene can complement the cys3-1 allele, and disruptions at this locus lead to cysteine auxotrophy. The predicted CYS3 product is closely related (46% identical) to the rat cystathionine gamma-lyase (Erickson et al., 1990), but differs in lacking cysteine residues. These results provide further evidence that the S288C strain of yeast resembles mammals in synthesizing cysteine solely via a trans-sulfuration pathway. The CYS3 product was found to have strong homology to three other enzymes involved in cysteine metabolism: the Escherichia coli metB and metC products and the S. cerevisiae MET25 gene product. The trans-sulfuration enzymes appear to form a diverged family and carry out related functions from bacteria to mammals.

Sequencing of chromosome I from Saccharomyces cerevisiae: analysis of a 32 kb region between the LTE1 and SPO7 genes

The DNA sequencing and preliminary functional analysis of a 32 kb section of yeast chromosome I has been completed. This region lies on the left arm of the chromosome between the LTE1 and SPO7 genes and contains 14 open reading frames (ORFs) positioned closely together, with an average spacing of approximately 350 nucleotides between coding regions. Three of these ORFs correspond to previously identified genes, a further three show significant homology with other proteins, while the remaining eight ORFs share no significant homology to genes in the databases.

Antibody to HIV-1, HTLV-I, and HCV in three populations of rural Haitians

The seroprevalence of antibodies to HIV-1, HTLV-I, and HCV was evaluated in three populations from northern rural Haiti: 1,727 patients attending the hospital for symptoms suggestive of HIV disease, 228 consecutive surgical patients, and 500 pregnant women were tested. HIV-1 seroprevalence was 6.1 and 4.0% in the last two groups, respectively, and 39.3% in the symptomatic population. Associated symptoms of wasting, cough, and diarrhea and a clinical diagnosis of AIDS were significantly predictive of HIV-1 seropositivity. Antibody to HTLV-I seroprevalence ranged from 2.2-5.3% in pregnant women, surgical patients, and HIV-seronegative symptomatic patients and was similar among the three groups when stratified by age. In contrast, HIV-1 seropositivity and HTLV-I seropositivity were significantly associated. The prevalence of confirmed antibody to HCV was low and not associated with either HIV-1 or HTLV-I seropositivity.

The effect of gamma-irradiation on the toxicity of malathion in V79 Chinese hamster cells and Molt-4 human lymphocytes

There is growing interest in the irradiation of food and agricultural products for insect disinfestation, sprout inhibition, delayed ripening and the reduction of microbiological loads. Extensive research has been done on this process, and irradiation to a maximum dose of 10 kGy is recognized as safe by national and international regulatory agencies. The question has been raised, however, whether irradiation of pesticide residues might produce radiation products that were more toxic or less toxic than the original pesticide. To address this question, we observed the effects of 10 kGy of gamma-radiation on malathion as measured by sister-chromatid exchange (SCE), micronuclei formation, cell survival, growth rate and polyploid formation. We found no significant differences between the effects of irradiated and unirradiated malathion on any of these end-points. Polyploid formation was the most dramatic effect of both irradiated and control malathion on V79 Chinese hamster cells. Cell survival, polyploid formation and growth rate were slightly better in cells treated with irradiated malathion. In Molt-4 human lymphocyte cells, micronuclei formation was not affected by irradiated or unirradiated malathion. Compared to malathion alone, the lack of such biological effects indicates that none of the presumed radiation-induced breakdown products increased or decreased the endpoints studied. The number of SCE was consistently, but not significantly, higher in the cells treated with irradiated malathion. There were no significant differences in cell survival or micronucleus formation in the human lymphocyte cell line Molt-4 treated with irradiated or control malathion. Thus, the irradiation of the pesticide malathion to 10 kGy, a recommended upper dose for most food irradiations, does not significantly alter its toxicity in these in vitro systems.

A comparison of two supplemental procedures for confirmation of antibody to hepatitis C virus c100-3 antigen in Louisiana blood donors

In a pilot study designed to evaluate the performance of supplemental hepatitis C virus (HCV) tests, 146 consecutive HCV enzyme immunoassay (EIA)-reactive samples (0.98% of 14,949 donors) were comparatively evaluated with two sets of supplemental tests: HCV antibody neutralization/c100-3 peptide EIA and the first-generation HCV recombinant immunoblot assay (RIBA). Of these samples, 68.5 percent were positive and 17.8 percent were negative on both supplemental assays. Nineteen samples were discordant. Eleven samples were positive on one assay (9 on neutralization/peptide, 2 on RIBA) and negative or indeterminate on the alternate supplemental test, but reacted with two additional HCV antigens outside the c100-3 region in a second-generation dot immunoblot assay. The dot immunoblot assay was used as a reference and reactive samples were considered confirmed. The remaining eight discordant samples were indeterminate or negative on either assay and did not react on the dot immunoblot assay. These data indicate a 0.74-percent prevalence of HCV exposure detected by reactivity with the c100-3 antigen in blood donors in southern Louisiana.

Comparative evaluation of supplemental hepatitis C virus antibody test systems

Implementation of routine blood donor screening using anti-hepatitis C virus (HCV) enzyme immunoassay (EIA) has resulted in an urgent need for well-characterized supplemental assays to confirm the presence of HCV antibodies. A comparative study of four commercially available supplemental assays is reported here: first- and second-generation versions of a strip recombinant immunoblot assay (RIBA-1 and RIBA-2), an HCV neutralization EIA, and HCV neutralization plus synthetic peptide EIA. Three hundred sixty-seven blood donor specimens that were repeatedly reactive on HCV EIA were studied. Most specimens (93%) were also evaluated by radioimmunoassay (RIA) with a six-antigen panel, and 60 selected specimens were tested for HCV RNA by the polymerase chain reaction (PCR). RIBA-1 and RIBA-2 gave concordant results with 86 percent of specimens, while an additional 13 percent were correctly classified by RIBA-2 but not RIBA-1. Neutralization EIA alone correctly identified 94 percent of the study group, while the remaining 6 percent required the peptide EIA or the combined neutralization-peptide assay system for correct classification. The RIBA-2 and neutralization-peptide assay system for correct classification. The RIBA-2 and neutralization-peptide assay systems yielded identical results for 86 percent of specimens, and these results were supported by RIA and selected PCR testing. Only 2 specimens (0.5%) were frankly discrepant, while 51 specimens were indeterminate on either (47) or both (4) assays. When either the RIBA-2 or neutralization-peptide assay yielded an indeterminate interpretation, the other system correctly classified the specimen (based on concordance with RIA and PCR data) in a high proportion (92%) of cases.(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of colcemid on the heat survival of mitotic V79 Chinese hamster cells

V79 Chinese hamster cells were collected by colcemid addition to study the effect of heat on mitosis. When they were heated at 42 degrees C and 45 degrees C in the presence of 0.06 micrograms/mL colcemid, cell survival increased over the control samples, which were heated in ordinary medium. Scanning electron microscopy showed that cells heated to 45 degrees C in the presence or absence of colcemid had fewer microvilli on the surface, but they did not have increased bleb formation. Transmission electron microscopy showed that the chromatin was diffuse in the heated cells and the kinetochores were indistinct. The mitochondria in the heated cells were also swollen and contained visible particles.

The effect of a chimeric mouse-human CD7 antibody on human T, natural killer, and lymphokine-activated killer cell activity in vitro

A chimeric CD7 antibody has been constructed with mouse variable and human constant regions and is currently being assessed in the prophylaxis of renal graft rejection. In this study we have investigated if this antibody or its murine parental form inhibits the function of a number of immune effector mechanisms involved in host defense against infection and/or malignancy. Most memory T cells and all natural killer cells express the CD7 antigen and could therefore be affected by CD7 antibody. Murine and chimeric CD7 antibodies significantly inhibit the alloproliferation of naive (65 +/- 4% and 66 +/- 8%, respectively) but not memory T cells (86 +/- 2% and 98 +/- 4%, respectively) in a primary mixed lymphocyte reaction relative to the negative control CD10 antibody (P less than 0.001). The memory T cell proliferative response to recall antigen is also largely unaffected by murine and chimeric CD7 antibodies relative to the negative control antibody (91 +/- 12% and 103 +/- 10%, respectively). The CD7 antigen is almost completely modulated from the surface of NK cells after incubation for 24 hr with either the murine or chimeric CD7, but not the CD10, negative control. The modulation of CD7 antigen by antibody, however, does not affect the cytotoxic function of either the NK or lymphokine-activated killer cells significantly. Preincubation with the chimeric antibody however, consistently showed a small inhibition relative to the negative control of 75-80% in NK assays and to 80-90% in LAK assays. These data suggest that both murine and chimeric CD7 antibodies may have a selective effect on alloproliferation but may largely spare a major component of the host's innate immunity as well as memory T cell proliferation to previously encountered antigens.

L-[3H]adenosine, a new metabolically stable enantiomeric probe for adenosine transport systems in rat brain synaptoneurosomes

The stereoenantimers D-[3H]adenosine and L-[3H]adenosine were used to study adenosine accumulation in rat cerebral cortical synaptoneurosomes. L-Adenosine very weakly inhibited rat brain adenosine deaminase (ADA) activity with a Ki value of 385 microM. It did not inhibit rat brain adenosine kinase (AK) activity, nor was it utilized as a substrate for either ADA or AK. The rate constants (fmol/mg of protein/s) for L-[3H]adenosine accumulation measured in assays where transport was stopped either with inhibitor-stop centrifugation or with rapid filtration methods were 82 +/- 14 and 75 +/- 10, respectively. Using the filtration method, the rates of L-[3H]adenosine accumulation were not significantly different from the value of 105 +/- 15 fmol/mg of protein/s measured for D-[3H]adenosine transport. Unlabeled D-adenosine and nitrobenzylthiolnosine, both at a concentration of 100 microM, reduced the levels and rates of L-[3H]adenosine accumulation by greater than 44%. These findings suggest that L-adenosine, a metabolically stable enantiomeric analog, and the naturally occurring D-adenosine are both taken up by rat brain synaptoneurosomes by similar processes, and as such L-adenosine may represent an important new probe with which adenosine uptake may be studied.