Immunopathologic responses to Aspergillus antigen in interleukin-4 knockout mice

Two strains of interleukin-4 (IL-4) gene knockout mice were studied and compared with wild strains to determine the role of IL-4 in the immunopathogenesis of murine allergic aspergillosis. Animals immunized intraperitoneally were subsequently challenged with Aspergillus antigen intranasally. The animals were evaluated for total serum immunoglobulin E (IgE) levels, Aspergillus-specific IgG antibody isotypes, peripheral blood eosinophils, cytokine and chemokine mRNA transcripts in spleen cells, and pulmonary histology. No serum IgE was detected in animals deficient in the IL-4 gene. Aspergillus-specific IgG1 was detected in all animals, while enhanced levels of IgG2a were detected in IL-4 knockout animals challenged with A. fumigatus antigen. There were no differences in the peripheral blood or lung eosinophils in the two groups of mice exposed to A. fumigatus. These results indicate that lung injury in Aspergillus-antigen challenged animals may be the result of the eosinophil mediators and that IgE-mediated injury may not be significant in this model, which may be a significant variation between the model and human allergic aspergillosis.

N-alkylated derivatives of [D-Pro10]dynorphin A-(1-11) are high affinity partial agonists at the cloned rat kappa-opioid receptor

As part of an effort to develop peptides with selective kappa-opioid antagonist activity, a series of N-alkylated [D-Pro10]dynorphin A-(1-11) derivatives were made through solid-phase peptide synthesis: R-Tyr-Gly-Gly-Phe-Leu-Arg-Arg-Ile-Arg-D-Pro-LysOH, where R = N-benzyl, N-cyclopropylmethyl, N,N-dicyclopropylmethyl, or N,N-diallyl. These derivatives and dynorphin A-(1-13)NH2 were evaluated for kappa-opioid receptor binding affinity and potency as inhibitors of adenylyl cyclase. Equilibrium competition binding experiments using [3H]diprenorphine (approximately 600 pM) were performed on membranes prepared from cultured Chinese hamster ovary (CHO) cells stably expressing the rat kappa-opioid receptor. Tissue prepared from this cell line was used to evaluate opioid peptide inhibition of forskolin-stimulated (50 microM) adenylyl cyclase activity. Displacement of [3H]diprenorphine specific binding by these peptides was observed with a rank order of affinity (Ki, nM) = [D-Pro10]dynorphin A-(1-11) (0.13) > dynorphin A-(1-13)NH2 (0.34) > N-cyclopropylmethyl- (1.4) > N,N-dicyclopropylmethyl- (12.6) approximately N-benzyl- (18.3) approximately N,N-diallyl-[D-Pro10]dynorphin A-(1-11) (26.0). A similar rank order was observed for potency of adenylyl cyclase inhibition (IC50, nM): [D-Pro10]dynorphin A-(1-11) (0.12) approximately dynorphin A-(1-13)NH2 (0.19) > N-cyclopropylmethyl- (2.7) > N,N-dicyclopropylmethyl- (13.2) approximately N,N-diallyl- (18.0) approximately N-benzyl-[D-Pro10]dynorphin A-(1-11) (36.4). The peptides differed in their percent maximal inhibition of adenylyl cyclase activity: dynorphin A-(1-13)NH2 (100%) approximately N-cyclopropylmethyl- (94.3%) approximately [D-Pro10]dynorphin A-(1-11) (87.9%) > N-benzyl- (71.4%) >> N,N-dicyclopropylmethyl- (23.6%) approximately N,N-diallyl-[D-Pro10]dynorphin A-(1-11)(18.9%). As the N,N-dicyclopropylmethyl- and N,N-diallyl-[D-Pro10]dynorphin A-(1-11) derivatives were found to have only weak partial agonist activity with respect to adenylyl cyclase inhibition, they were evaluated for their ability to reverse dynorphin A-(1-13)NH2 (10 nM) inhibition of adenylyl cyclase activity. N,N-dicyclopropylmethyl- and N,N-diallyl-[D-Pro10]dynorphin A-(1-11) reversed dynorphin A-(1-13)NH2 inhibition to levels equal to the maximal inhibition produced by N,N-dicyclopropylmethyl- and N,N-diallyl-[D-Pro10]dynorphin A-(1-11) alone. This weak partial agonism combined with nanomolar potency render the N,N-dicyclopropylmethyl- and N,N-diallyl-[D-Pro10]dynorphin A-(1-11) compounds promising leads for further attempts to synthesize peptide kappa-opioid receptor antagonists.

Novel fluoroquinolone antibacterial agents containing oxime-substituted (aminomethyl)pyrrolidines: synthesis and antibacterial activity of 7-(4-(aminomethyl)-3-(methoxyimino)pyrrolidin-1-yl)-1-cyclopropyl-6- fluoro-4-oxo-1,4-dihydro[1,8]naphthyridine-3-carboxylic acid (LB20304)

New pyrrolidine derivatives, which bear an alkyloxime substituent in the 4-position and an aminomethyl substituent in the 3-position of the pyrrolidine ring, have been synthesized and coupled with various quinolinecarboxylic acids to produce a series of new fluoroquinolone antibacterials. These fluoroquinolones were found to possess potent antimicrobial activity against both Gram-negative and Gram-positive organisms, including methicillin resistant Staphylococcus aureus (MRSA). Variations at the C-8 position of the quinolone nucleus included fluorine, chlorine, nitrogen, methoxy, and hydrogen atom substitution. The activity imparted to the substituted quinolone nucleus by the C-8 substituent was in the order F (C5-NH2) > F (C5-H) > naphthyridine > Cl = OMe = H against Gram-positive organisms. In the case of Gram-negative strains, activity was in the order F (C5-NH2) > naphthyridine = F (C5-H) > H > Cl > OMe. The advantages provided by the newly introduced oxime group of the quinolones were clearly demonstrated by their comparison to a desoximino compound 30. In addition, the oxime moiety greatly improved the pharmacokinetic parameters of the novel quinolones. Among these compounds, compound 20 (LB20304) showed the best in vivo efficacy and pharmacokinetic profile in animals, as well as good physical properties. The MICs (microgram/mL) of LB20304, compound 30, and ciprofloxacin against several test organisms are as follows: S. aureus 6538p (0.008, 0.031, and 0.13), methicillin resistant S. aureus 241 (4, 16, and 128), Streptococcus epidermidis 887E (0.008, 0.016, and 0.13), methicillin resistant S. epidermidis 178 (4, 32, and 128), Enterococcus faecalis 29212 (0.063, 0.13, and 1), Pseudomonas aeruginosa 1912E (0.25, 0.5, and 0.13), Escherichia coli 3190Y (0.008, 0.016, and 0.008), Enterobacter cloacae P99 (0.008, 0.031, and 0.008), Actinobacter calcoaceticus 15473 (0.063, 0.13, and 0.25). On the basis of these promising results, LB20304 was selected as a candidate for further evaluation.

Transverse carpal ligament: its effect on flexor tendon excursion, morphologic changes of the carpal canal, and on pinch and grip strengths after open carpal tunnel release

A three-part study is described that examines postoperative weakness after open carpal tunnel release and investigates the role of the transverse carpal ligament in the digital flexor pulley system. The effect of this ligament on flexor tendon excursion is evaluated in a cadaver study. Magnetic resonance imaging analysis is used to determine whether division of the transverse carpal ligament promotes volar migration of the median nerve and flexor tendons. Finally, the effects of ligament division and various methods of transverse carpal ligament reconstruction on the return of grip and pinch strengths after open carpal tunnel release are evaluated. The authors were able to determine that transverse carpal ligament reconstruction, particularly the transposition flap repair technique, after open carpal tunnel release confers a mechanical advantage and that the transverse carpal ligament is an important pulley for flexor tendon excursion. Based on the magnetic resonance imaging studies, volar displacement of carpal contents is reduced in patients undergoing transverse carpal ligament reconstruction by means of a transposition flap compared with those undergoing no ligament reconstruction and those undergoing reconstruction using the palmar aponeurosis. Postoperative grip and pinch strength values for the transposition flap repair group surpassed those of the other two groups at 12 weeks.

Synthesis and opioid activity of [D-Pro10]dynorphin A-(1-11) analogues with N-terminal alkyl substitution

Several N-terminal di- and monoalkylated derivatives of [D-Pro10]dynorphin A-(1-11) were synthesized in order to explore the structure-activity relationships for antagonist vs agonist activity at kappa-opioid receptors. N,N-Dialkylated and N-monoalkylated (alkyl = allyl, benzyl, and cyclopropylmethyl (CPM) tyrosine derivatives were prepared from tyrosine tert-butyl ester and the corresponding alkyl halides. [D-Pro10]Dyn A-(2-11) was prepared by solid phase synthesis using Fmoc-protected amino acids, and the tyrosine derivatives were coupled to the peptide with BOP ((benzotriazol-1-yloxy)tris(dimethylamino)phosphonium hexafluorophosphate). Both the degree of substitution and the identity of the alkyl group affected kappa-receptor affinity, selectivity, and efficacy. All of the N-monoalkylated derivatives exhibited much higher affinity (Ki < 0.05 nM) for kappa receptors in the guinea pig cerebellum and greatly enhanced kappa-receptor selectivity (Ki ratio (kappa/mu) > 200) compared to the N,N-dialkyl [D-Pro10]Dyn A-(1-11) analogues, although one disubstituted analogue, N,N-diCPM[D-Pro10]Dyn A-(1-11), retained high affinity (Ki = 0.19 nM) for kappa receptors. Thus the introduction of the second alkyl group at the N-terminus lowered kappa-receptor affinity and selectivity. The N-allyl and N-CPM analogues were moderately potent agonists in the guinea pig ileum (GPI) assay, while the N-benzyl derivative was a weak agonist in this assay. In vivo in the phenylquinone abdominal stretching assay the N-CPM analogue exhibited potent antinociceptive activity (ED50 = 1.1 micrograms/mouse), while N-allyl[D-Pro10]Dyn A-(1-11) exhibited weak antinociceptive activity (ED50 = 27 micrograms/mouse). For the N,N-dialkyl derivatives the identity of the N-terminal alkyl group affected the efficacy observed in the smooth muscle assays. The N,N-diCPM analogue exhibited negligible agonist activity, and N,N-diallyl[D-Pro10]Dyn A-(1-11) showed weak antagonist activity against Dyn A-(1-13)NH2 in the GPI. In contrast, the N,N-dibenzyl compound showed appreciable opioid agonist activity in this assay. In vivo the N,N-diallyl analogue exhibited weak antinociceptive activity (ED50 = 26 micrograms/mouse in the phenylquinone abdominal stretching assay). The N-monoalkylated peptides are among the most kappa-selective opioid peptides reported to date, showing comparable or greater selectivity and higher affinity than the kappa-selective non-peptide agonists U-50,488 and U-69,593. The N,N-diCPM and N,N-diallyl peptides are lead compounds in the development of peptide-based kappa-receptor antagonists.

Regulation of developing dopaminergic axonal arbor size in three-dimensional reaggregate tissue culture

The role of target availability in determining axonal size of the developing dopaminergic neuron was examined in three-dimensional reaggregate culture in which these neurons undergo normal neurochemical and morphological development. The ratio of striatal target cells to dopaminergic neurons was systematically increased from 2:1 to 50:1 (striatal to mesencephalic cells). These ratios provide sufficient target for quantitative survival of dopaminergic neurons similar to that seen in vivo. After 3 weeks in culture, dopamine levels increased linearly and proportionally to dopaminergic cell number over a 25-fold relative increase in target cell availability. The amount of neurotransmitter per dopaminergic cell remained constant, suggesting that the axonal arbor did not increase as a function of target availability. This conclusion was directly tested by morphological analysis of the dopaminergic axonal arbor in single aggregates containing between 0 and 45 dopaminergic cells under conditions in which sufficient target was not a factor in dopaminergic cell survival. As was the case with respect to dopamine concentration, axonal arbor size per cell remained constant in the face of increasing target availability. Thus, availability of target cells under these conditions, is not, per se, the limiting factor on the rate of growth of the developing dopaminergic axonal arbor.

The effect of promoter strength in adenoviral vectors containing herpes simplex virus thymidine kinase on cancer gene therapy in vitro and in vivo

The use of adenoviral vectors to deliver the herpes simplex virus thymidine kinase (HSVtk) gene followed by treatment with the prodrug ganciclovir (GCV) has promise for a variety of applications where excess cell proliferation is detrimental such as treatment of tumors and vascular restenosis. Optimizing this system is thus an important goal. The purpose of this study was to determine if the induction of higher levels of HSVtk expression would augment the sensitivity to GCV. This was accomplished by generating adenoviral vectors that expressed HSVtk from promoters of different efficiencies (the CMV versus RSV promoters). Despite higher levels of HSVtk expression per cell with the CMV promoter, there was no significant enhancement of antitumor effects between RSV- and CMV-driven adenovirus vectors in in vitro and in vivo studies indicating that simply increasing HSVtk enzyme levels per cell above a minimal threshold level will not be effective in augmenting the HSVtk/GCV system. These results suggest that other strategies, e.g., the use of higher doses of GCV, augmentation of the "bystander effect," the generation of mutant HSVtk genes with higher substrate affinities, the discovery of improved vectors with increased transduction efficiencies, or the development of new prodrugs with higher affinities for HSVtk will therefore be needed to enhance therapeutic responses.

Improvement of the 3'-5' exonuclease activity of Taq DNA polymerase by protein engineering in the active site

Taq DNA polymerase from Thermus aquaticus has been shown to be very useful in the polymerase chain reaction method. Taq DNA polymerase has a domain at its amino terminus (residue 1 to 291) that has a 5'-3' exonuclease activity, a 3'-5' exonuclease domain in the middle (residue 292 to 423), and a domain at its C-terminus that catalyzes polymerase reactions. Taq DNA polymerase is classified into the polI family which is represented by E. coli DNA polymerase I. The three dimensional structural alignment of 3'-5' exonuclease domains from the polI family, DNA polymerases leads us to understand why Taq DNA polymerase does not carry out proof-reading in the polymerase chain reaction. Three sequence motifs, called ExoI, II, and III must be present in order to carry out proof-reading by the 3'-5' exonuclease reaction in DNA polymerization, but Taq DNA polymerase contains none of them. The key catalytic module in the 3'-5' exonuclease is two metal ions chelated by active-site carboxylic amino acids. In order to render the 3'-5' exonuclease activity in Taq DNA polymerase, a catalytic module was constructured in the active site by protein engineering. The mutant Taq DNA polymerase shows twice as much the 3'-5' exonuclease activity as that of wild-type DNA polymerase.

Combination of tracheal gas insufflation and airway pressure release ventilation

STUDY OBJECTIVE

We hypothesized that the continuous gas flow administration delivered through an insufflation catheter positioned above the carina during airway pressure release ventilation (APRV) would facilitate carbon dioxide (CO2) elimination, resulting in normocarbia with a substantially reduced peak airway pressure (Paw). To test this hypothesis, we compared intermittent positive pressure ventilation (IPPV), tracheal gas insufflation (TGI), APRV, and combined TGI and APRV (TGI + APRV).

DESIGN

Animal study with random application of four ventilatory modes in a canine restrictive-thorax model with and without pulmonary edema.

SETTING

Research laboratory at Kumamoto (Japan) University School of Medicine.

SUBJECTS

Six mongrel dogs.

INTERVENTIONS

Application of four ventilatory modes (IPPV, TGI, APRV, and TGI + APRV).

MEASUREMENTS AND RESULTS

TGI + APRV facilitated CO2 elimination. The peak Paw was significantly lower during TGI + APRV than during IPPV (nonpulmonary edema model; 15 +/- 4 vs 28 +/- 9 cm H2O; p < 0.05; pulmonary edema model: 20 +/- 4 vs 34 +/- 10 cm H2O; p < 0.05). Normocarbia was observed in both models. Neither TGI nor APRV alone maintained normocarbia.

CONCLUSION

The combined use of TGI and APRV is a more effective method of maintaining normocarbia with reduced peak Paw than either IPPV or APRV alone.

Mapping murine loci for seizure response to kainic acid

Mature DBA/2J (D2) mice are very sensitive to seizures induced by various chemical and physical stimuli, whereas C57BL/6J (B6) mice are relatively seizure resistant. We have conducted a genome-wide search for quantitative trait loci (QTLs) influencing the differential sensitivity of these strains to kainic acid (KA)-induced seizures by studying an F2 intercross population. Parental, F1, and F2 mice (8-10 weeks of age) were injected subcutaneously with 25 mg/kg of KA and observed for 3 h. Latencies to focal and generalized seizures and status epilepticus were recorded and used to calculate an overall seizure score. Results of seizure testing indicated that the difference in susceptibility to KA-induced seizures between D2 and B6 mice is a polygenic phenomenon with at least 65% of the variance due to genetic factors. First-pass genome screening (10-cM marker intervals) in F2 progeny (n = 257) documented a QTL of moderate effect on Chromosome (Chr) 1 with a peak LOD score of 5.5 (17% of genetic variance explained) localized between D1Mit30 and D1Mit16. Provisional QTLs of small effect were detected on Chr 11 (D11Mit224-D11Mit14), 15 (D15Mit6-D15Mit46) and 18 (D18Mit9-D18Mit144). Multiple locus models generally confirmed the Mapmaker/QTL results and also provided evidence for another QTL on Chr 4 (D4Mit9). Multilocus analysis of seizure severity suggested that additional loci on Chrs 5 (D5Mit11), 7 (D7Mit66), and 15 (D15Nds2) might also contribute to KA-induced seizure response. Overall, our results document a complex genetic determinism for KA-induced seizures in these mouse strains with contributions from as many as eight QTLs.

Role of particulate antigens of Aspergillus in murine eosinophilia

OBJECTIVE

Allergic bronchopulmonary aspergillosis, a disabling hypersensitivity lung disease, results from inhalation of Aspergillus fumigatus antigens present in contaminated environments. A murine model has been developed to understand the immune mechanism involved in allergic bronchopulmonary aspergillosis. We have investigated the immunoregulatory role of different physical forms of A.fumigatus antigens, such as A.fumigatus spores, soluble antigens. and soluble antigen coupled inert particles, in the model.

METHODS

BALB/c mice were exposed to soluble A.fumigatus antigens, spores, or inert particles of comparable size to the spores coupled with A.fumigatus soluble antigens. Antibody and eosinophil response, pulmonary pathology, and cytokine expressions were studied.

RESULTS

Peripheral blood eosinophilia and pulmonary inflammation with influx of eosinophils into the lung was detected more in animals exposed to particulate antigens than in those exposed to soluble antigen. However, the total serum IgE and Aspergillus-specific IgG levels showed only a slight increase in the former groups as opposed to elevated levels in animals exposed to soluble antigen. The cytokine expression in in vitro antigen stimulated spleen cells showed a typical Th2 pattern in all antigen-exposed animals. IL-5 mRNA could be detected in the spleen cells cultured with antigen from all groups of antigen-exposed animals.

CONCLUSION

Particulate A.fumigatus antigens induced eosinophilia in mice prior to the elevation of serum IgE levels. This pattern of IgE and eosinophilia is reversed with the soluble antigen exposure in this model.

A linkage study of bipolar illness

BACKGROUND

Although genetic epidemiological studies of bipolar (BP) illness are consistent with a heritable component, inherited risk factors remain unknown. The goal of the present study is to describe the localization of BP susceptibility loci through linkage strategies, including a genome-wide search.

METHODS

A linkage study of 22 BP families has been performed. These BP families include almost 400 persons, 173 of whom have been diagnosed as having BP I, schizoaffective, BP II with major depression, or recurrent unipolar illness. Using an autosomal dominant disease model with 85% or 50% age-dependent penetrance, and a recessive model with 85% penetrance, linkage analyses were performed assuming a narrow (BP and schizoaffective) or a broad (BP, schizoaffective, or unipolar) definition of the BP spectrum. Affected sibling pairs and affected pedigree member analyses were performed when positive lod scores were observed in multiple pedigrees. The present article describes linkage analysis of 310 DNA markers on chromosomes 1, 5p, 6, 8, 10q, 11q, and 12 to 18.

RESULTS

None of the loci examined disclosed compelling evidence for linkage using lod score analyses. Model-independent analysis by multilocus affected pedigree member method in the pericentromeric chromosome 18 region disclosed statistically significant evidence (P < .0001) for a BP susceptibility gene in this region. Multilocus analysis by affected sibling pair method also disclosed evidence for linkage (P < .00008).

CONCLUSIONS

Our results imply that a BP susceptibility gene exists near the centromere of chromosome 18. Confirmation of this finding (by independent investigators studying different pedigrees) has been published, suggesting that a valid BP disease linkage may have been discovered.

Dynamic-robotic telepathology: Department of Veterans Affairs feasibility study

In this retrospective study, we assess the accuracy, confidence levels, and viewing times of two generalist pathologists using both dynamic-robotic telepathology and conventional light microscopy (LM) to render diagnoses on a test set of 100 consecutive routine surgical pathology cases. The objective is to determine whether telepathology will allow a pathology group practice at a diagnostic hub to provide routine diagnostic services to a remote hospital without an on-site pathologist. For TP, glass slides were placed on the motorized stage of the robotic microscope of a telepathology system by a senior laboratory technologist in Iron Mountain, MI. Real-time control of the motorized microscope was then transferred to a pathologist in Milwaukee, WI, who viewed images of the glass slides on a video monitor. The telepathologists deferred rendering a diagnosis in 1.5% of cases. Clinically important concordance between the individual diagnoses rendered by telepathology and the "truth" diagnoses established by rereview of glass slides was 98.5%. In the telepathology mode, there were five incorrect diagnoses out of a total of 197 diagnoses. In four cases in which the telepathology diagnosis was incorrect, the pathologist's diagnosis by LM was identical to that rendered by telepathology. These represent errors of interpretation and cannot be ascribed to telepathology. The certainty of the pathologists with respect to their diagnoses was evaluated over time. Results for the first 50 cases served as baseline data. For the second 50 cases, confidence in rendering a diagnosis in the telepathology mode was essentially identical to that of making a diagnosis in the LM viewing mode. Viewing times in the telepathology mode also improved with more experience using the telepathology system. These results support the concept that an off-site pathologist using dynamic-robotic telepathology can substitute for an on-site pathologist as a service provider.

Recombinant adenovirus deleted of all viral genes for gene therapy of cystic fibrosis

Recombinant adenoviruses are being developed for gene therapy of inherited disorders such as cystic fibrosis because they efficiently transduce recombinant genes into nondividing cells in vivo. First generation recombinant adenoviruses, rendered defective by deletion of sequences spanning E1a and E1b, express low levels of early and late viral genes that activate destructive cellular immune responses. Current strategies for improving recombinant adenoviruses attempt to inactivate other essential genes through deletion and growth in new packaging cell lines or incorporation of temperature sensitive mutations which allow propagation of the virus in available packaging cell lines at permissive temperatures. We describe in this report a new type of recombinant adenovirus that is deleted of all viral open reading frames. This recombinant (called delta-rAd), which contains only the essential cis elements (i.e., ITRs and contiguous packaging sequence), is propagated in 293 cells in the presence of E1-deleted helper virus. Concatamers of the monomeric vector genome were passaged and capable of transduction. The delta-rAd genome is packaged into virions that sediment at a lower density than the helper virus in cesium gradients forming the basis for a purification protocol. A fully deleted recombinant adenovirus that expresses human cystic fibrosis transmembrane conductance regulator was produced and used to transduce human airway epithelial cells derived from a cystic fibrosis patient. Packaging and propagation of a fully deleted adenovirus is an important step toward the development of a safer vector. Improved production and purification strategies need to be developed before this new vector system can be evaluated in vivo.

Anatomic delineation of the ulnar nerve and ulnar artery in relation to the carpal tunnel by axial magnetic resonance imaging scanning

In a number of publications the distal branches of both the ulnar artery and ulnar nerve have been identified as being positioned ulnar to the hook of the hamate. We undertook a magnetic resonance imaging project in patients who presented for carpal tunnel release to determine how far radially vital structures of Guyon's canal may be located and if they may overlap the carpal tunnel at the hook of the hamate. Cross-sectional magnetic resonance imaging scans of 20 patients were performed prior to carpal tunnel release with the wrist positioned in neutral, flexed, and extended positions. Linear measurements were made either radial or ulnar to the hook of the hamate taken as the reference point. In the neutral position, the ulnar nerve was found to be, on average, 3.6 mm ulnar to the hook of the hamate (range of 5.8 mm radial to 7.5 mm ulnar). The ulnar artery averaged 0.7 mm to the radial side of the hook of the hamate (range 7.8 mm radial to 2.8 mm ulnar). Guyon's canal extended 28% of the way across the carpal ligament (range 9 to 63%). With the wrist in flexion and extension, there was an ulnar displacement and a radial displacement, respectively, of these structures relative to the hook of the hamate.

Interferon-gamma and tumor necrosis factor-alpha protect mice from invasive aspergillosis

The immunopathogenesis of invasive aspergillosis and the role played by cytokines are not fully understood. The roles of interferon (IFN)-gamma and tumor necrosis factor (TNF)-alpha were investigated in BALB/c mice infected intravenously with 5 x 10(5) Aspergillus fumigatus conidia. Eight groups of animals were studied, including 2 control groups (mice only infected with A. fumigatus and those given cortisone acetate and infected with A. fumigatus) and 6 groups of infected mice either treated or not treated with cortisone acetate and given IFN-gamma, anti-IFN-gamma, TNF-alpha, or anti-TNF-alpha. No deaths occurred among the mice treated with IFN-gamma and TNF-alpha, compared with 40%-80% mortality in the other groups. IFN-gamma- and TNF-alpha-treated mice also had fewer organs from which A. fumigatus could be cultured or demonstrated on histologic examination. These observations suggest that IFN-gamma and TNF-alpha have protective roles in invasive aspergillosis.

Catalytically active forms of the individual subunits of Vibrio harveyi luciferase and their kinetic and binding properties

Contradictory findings have recently been reported regarding the (in)abilities of individual subunits of the Vibrio harveyi alpha beta dimeric luciferase to catalyze bioluminescence. We have produced individual alpha and beta subunits separately in Escherichia coli JM109 cells by recombinant DNA techniques. Both subunits were purified to more than 90% homogeneity and found to be catalytically active, with their general catalytic properties and the specific activities similar to those reported earlier (Sinclair, J. F., Waddle, J. J., Waddill, E. F., and Baldwin, T. O. (1993) Biochemistry 32, 5036-5044). Individual subunits were significantly distinct from the native luciferase with respect to inactivations by trypsin and N-ethylmaleimide, and the stability of the flavin 4a-hydroperoxide intermediate. The active species in isolated alpha and beta samples were each the predominant protein species, corresponding to a 42,000 M(r) alpha monomer and a 67,000 M(r) beta dimer, respectively. These findings clearly indicate that the activities of the individual subunits are not due to trace contaminations of the respective counter subunits. The much reduced specific activities of the individual subunits are, in part, a consequence of diminished abilities to oxidize the aldehyde substrate. Kinetic and equilibrium measurements indicate that alpha and beta 2 each contained a reduced flavin site, an aldehyde substrate site, and an aldehyde inhibitor site. The on and off rates of the decanal inhibitor binding were substantially slower than the bindings of decanal and reduced riboflavin 5'-phosphate substrates. These findings are consistent with a scheme that the aldehyde inhibitor blocks the binding of the reduced flavin substrate.

Percutaneous drainage of splenic abscess in typhoid fever--a case report

Salmonella typhi splenic abscesses are a very rare complication of typhoid fever. Splenectomy is the standard surgical treatment for these lesions. But these days, with improvements in imaging techniques, percutaneous drainage of splenic abscesses has been demonstrated to be one of the alternative treatment in selected cases. We report the case of a 7 year-old male, who presented with Salmonella typhi in blood and urine cultures, and a 1: 320 in O titer of Widal test. Ultrasound and computed tomography showed a single splenic abscess, 3 cm in diameter. He was treated with antibiotics, but the symptoms were not relieved. Thus we performed the percutaneous drainage of the splenic abscess under ultrasound guidance. A culture of the aspirated material was positive for Salmonella typhi, and the boy's condition improved. We think that percutaneous drainage of a single lesion was an excellent alternative to surgery, particularly because our patient was young and spleen conservation was desirable.

Pigeon-serum-induced hypersensitivity pneumonitis in the dog

Pigeon serum (PS) is one of the most common causes of hypersensitivity pneumonitis (HP). PS-induced HP was examined in a dog model. The dogs (n = 6) were immunized by i.m. injections of PS, followed by insufflation with aerosolized PS, while all control dogs (n = 3) received saline only. All animals insufflated with PS developed tachypnea 2-4 h after PS inhalation. After PS insufflation, a significant decrease in arterial oxygen tension (PaO2) was detected in sensitized dogs. No change in PaO2 was detected in sensitized dogs after saline or in the controls after PS insufflation. In intradermal skin tests with PS antigen, a positive skin reaction was found in 3/6 dogs in 30 min, and in 5/6 dogs in 6 and 48 h after the PS injections. Sensitized dogs showed a significant increase in PS-specific IgG in serum and lavage fluid (LF). In LF of sensitized dogs, an increase in the percentage of lymphocytes, eosinophils, and neutrophils was detected. Sensitized dogs developed chronic interstitial inflammation with lymphocytes, macrophages, plasma cells, and eosinophils in lungs. Granulomas with lymphocytes, histiocytes, and giant cells were detected in both the interstitium and the bronchiolar wall in the lungs of sensitized dogs. PaO2 was lowest in dogs showing the most severe interstitial inflammation in the lungs. The results indicate that dogs can be successfully used in immunologic and physiologic studies of PS-induced HP.

Stopped lower buffer flow electrofractionation: simple electrofractionation for complex protein mixture

The standard electrofractionation technique simulated the liquid chromatography to create a continuous elution system. Though this continuous lower buffer flow electrofractionation system served as an excellent model for preparative electrophoresis, the restricted current flow caused by electric resistance arising from the column holder prevented the application to the purification of complex protein mixtures. To overcome the electric current problem, the stopped lower buffer flow electrofractionation (SFE) system is designed to work without using a column holder and use prestained markers as the detection tool of protein position during the electrofractionation process. Through this improvement, the SFE system widens the availability of electrofractionation to the purification of complex and low-concentration protein mixtures. In this report, the efficiency of this technique is shown through the partial purification of a 32P-labeled protein in the rat liver microsome.

Latex-induced dermal and pulmonary hypersensitivity in rabbits

BACKGROUND

Natural rubber latex (NRL) causes immediate, IgE-mast cell-mediated reactions in sensitized individuals, especially among health care workers and children with spina bifida. The immunopathogenesis of the reaction is obscure.

METHODS

To study the immunologic mechanisms of NRL allergy, rabbits were sensitized with two nonammoniated and one ammoniated NRL antigens. Subcutaneous and intratracheal injections were used to immunize rabbits. Intradermal skin tests, IgG antibodies against NRL in serum and lung lavage fluid, and pulmonary histologic features were evaluated.

RESULTS

One of nine sensitized rabbits died of anaphylaxis immediately after the third intratracheal injection with nonammoniated NRL. All sensitized rabbits, but not the controls, showed an immediate wheal and flare reaction in intradermal skin testing with NRL antigens. A positive skin reaction was detected 6 and 48 hours after the intradermal injections in four of five sensitized rabbits. A significant increase in NRL-specific IgG antibodies was detected in serum and lung lavage fluid of immunized rabbits. Lung histologic evaluation of NRL-sensitized rabbits showed a granulomatous interstitial and bronchial inflammation with a predominance of eosinophils and histiocytes in both intratracheally and subcutaneously sensitized rabbits. Vasculitis, hypertrophia, and contraction of pulmonary arteries could be detected in sensitized animals.

CONCLUSION

The results of the first NRL rabbit model study indicate that eosinophils and IgE antibodies play a major role in the immunopathogenesis of NRL-induced allergy and anaphylaxis. A wide range of inflammatory responses detected in rabbits injected by subcutaneous route without intratracheal exposure suggests that NRL exposure may pose a risk for a subsequent systemic reaction.