Immunization with gp96 from Listeria monocytogenes-infected mice is due to N-formylated listerial peptides

N-Formylated (N-f-met) peptides derived from proteins of the intracellular bacterium Listeria monocytogenes generate a protective, H2-M3-restricted CD8 T cell response in C57BL/6 mice. N-f-met peptide-specific CTL were generated in vitro when mice previously immunized with gp96 isolated from donor mice infected with L. monocytogenes were stimulated with these peptides. No significant peptide-specific CTL activity was observed in mice immunized with gp96 from uninfected animals. Masses corresponding to one N-f-met peptide were found by matrix-assisted laser desorption/ionization-mass spectrometry on gp96 isolated from C57BL/6 mice infected with L. monocytogenes, but not on gp96 from noninfected mice. Therefore, bacterial N-f-met peptides from intracellular bacteria can bind to gp96 in the infected host, and gp96 loaded with these peptides can generate N-f-met-peptide-specific CTL. We assume a unique role of gp96 in Ag processing through the H2-M3 pathway.

Isochromosome 1q as an early genetic event in a child with intracranial ependymoma characterized by molecular cytogenetics

Data concerning cytogenetic features of childhood ependymoma are rare. In this article, a gain of 1q was identified as the sole alteration in a primary childhood infratentorial ependymoma by comparative genomic hybridization (CGH). A recurrence of this brain tumor was studied using multiplex-fluorescence in situ hybridization (M-FISH) in addition to CGH and G-banding analysis. In accordance with the primary tumor, a gain of 1q corresponding to an isochromosome 1q was observed indicating an early event in the tumor development. Furthermore, M-FISH classified several other rearranged chromosomes including 6q and 17p that have previously been found to be involved in the development and progression of childhood ependymoma.

Functional isolation of the Candida albicans FCR3 gene encoding a bZip transcription factor homologous to Saccharomyces cerevisiae Yap3p

We have isolated a C. albicans gene, named FCR3 (for fluconazole resistance 3), based upon its ability to suppress the FCZ hypersusceptibility of a Saccharomyces cerevisiae mutant strain (JY312) lacking the transcription factors Pdr1p and Pdr3p. The FCR3 ORF (1200 bp) encodes a 399 amino acid protein containing a basic leucine zipper (bZip) domain. Fcr3p displays the highest level of sequence homology with the S. cerevisiae Yap3p protein (34% identity, 45% similarity). We had previously shown that deletion of the PDR5 gene encoding a multidrug transporter completely abolished the ability of FCR3 to suppress the FCZ hypersusceptibility of JY312, suggesting that FCR3 confers FCZ resistance by activating PDR5 expression. We show here that the beta-galactosidase activity of a PDR5 promoter-lacZ construct in JY312 is increased two-fold upon FCR3 overexpression, demonstrating that FCR3 regulates PDR5 at the transcriptional level. We also show that FCR3 overexpression not only suppresses the hypersusceptibility of JY312 to 4-nitroquinoline-N-oxide (4-NQO) but also confers higher levels of resistance to this compound as compared to the wild-type KY320 strain. Since PDR5 is not involved in 4-NQO resistance, this result indicates that FCR3 can also activate the transcription of other genes that can confer 4-NQO resistance. Finally, Northern blot analysis indicates that FCR3 encodes a single 2.4 kb RNA transcript in C. albicans, suggesting that the FCR3 mRNA contains long 5' and/or 3' untranslated regions. The nucleotide sequence of the FCR3 gene has been deposited at GenBank under Accession No. AF342983.

Flow cytometry detection of platelet procoagulation activity and microparticles in patients with unstable angina treated by percutaneous coronary angioplasty and stent implantation

Platelet activation is known to participate to the pathogenesis of acute coronary syndromes. Aminophospholipid exposure and microparticles shedding are hallmarks of full platelet activation and may account for the dissemination of prothrombotic seats. Using flow cytometry analysis of annexin V binding to externalized aminophospholipids, we followed platelet procoagulant activity (PPA) and platelet microparticles (PMP) shedding in venous and coronary whole blood samples from 30 patients with unstable angina before and after percutaneous coronary angioplasty (PTCA) and stent implantation. Baseline values of PPA and PMP were significantly more elevated in patients than in control subjects (p < 0.005). PMP percentage was significantly higher in coronary than in venous blood, and in coronary blood of patients with proximal instead of mid/distal lesions of coronary arteries. No enhancement of platelet reactivity to TRAP and collagen was induced by procedure. Whereas activated GpIIb-IIIa and P-selectin expression decreased 24 h and 48 h after procedure, PPA and PMP remained as elevated as before. Thus, flow cytometry is a reliable method for detection of fully activated platelets in whole blood samples. Annexin V binding analysis demonstrates the persistance of in vivo platelet activation, despite the use of antiaggregating agents.

Suburban transmission of Q fever in French Guiana: evidence of a wild reservoir

The annual incidence of Q fever in French Guiana was found to have increased in 1996 and was 37/100,000 population over the last 4 years. Subsequent investigations in Cayenne and its suburbs indicated that a wild reservoir of the bacteria was responsible for the epidemiologic pattern. A case-control study showed that residence near a forest and occupations and activities that result in exposure to aerosols of dusts from the soil are risk factors for Q fever. By means of time-series analysis, a strong positive correlation between rainfall and the incidence of Q fever with a time lag of 1-3 months was found. The spatial distribution of the cases showed that transmission occurs widely throughout greater Cayenne, which is incompatible with a pinpoint source of contamination. Transmission from livestock and dissemination of the bacteria by the wind appeared to be unlikely, which strengthens the hypothesis that a wild reservoir is responsible for transmission.

Substrate binding to DNA photolyase studied by electron paramagnetic resonance spectroscopy

Structural changes in Escherichia coli DNA photolyase induced by binding of a (cis,syn)-cyclobutane pyrimidine dimer (CPD) are studied by continuous-wave electron paramagnetic resonance and electron-nuclear double resonance spectroscopies, using the flavin adenine dinucleotide (FAD) cofactor in its neutral radical form as a naturally occurring electron spin probe. The electron paramagnetic resonance/electron-nuclear double resonance spectral changes are consistent with a large distance (> or =0.6 nm) between the CPD lesion and the 7,8-dimethyl isoalloxazine ring of FAD, as was predicted by recent model calculations on photolyase enzyme-substrate complexes. Small shifts of the isotropic proton hyperfine coupling constants within the FAD's isoalloxazine moiety can be understood in terms of the cofactor binding site becoming more nonpolar because of the displacement of water molecules upon CPD docking to the enzyme. Molecular orbital calculations of hyperfine couplings using density functional theory, in conjunction with an isodensity polarized continuum model, are presented to rationalize these shifts in terms of the changed polarity of the medium surrounding the FAD cofactor.

Occurrence of C-reactive protein in cryoglobulins

A previous case report described the formation of a complex between a monoclonal IgA with cryolabile properties and C-reactive protein (CRP). Our study provides the first evidence for the frequent occurrence of CRP in cryoglobulins (Cg) of all three types according to Brouet's classification. We performed a systematic immunochemical analysis of cryoglobulins from 18 patients by Western blotting and in 15 of 18 cryoprecipitates a single band (23 KD), immunoreactive with anti-CRP antibody, was demonstrable irrespective of the clonal composition of the cryoglobulins. This band was detectable in 4/5 of type I, in 6/8 of type II, and in 5/5 of type III cryoprecipitates, classified according to Brouet et al. In addition, the complement proteins C1q and C3 were present in nearly all CRP-containing cryoglobulins, presumably reflecting previous activation of the classical complement pathway at least. All three CRP-negative cryoprecipitates were derived from sera with low cryoglobulin content (1-2 g/l). Longitudinal investigation of 23 cryoprecipitates from seven patients confirmed that successful detection of CRP by Western blotting depends on the protein concentration of the cryoglobulins. Since complexed CRP was previously shown to be an effective activator of complement, via C1q binding, CRP may modulate pathophysiologic effects mediated by cryoglobulins in vivo.

Localization of processes involved in methanogenic degradation of rice straw in anoxic paddy soil

In anoxic paddy soil, rice straw is decomposed to CH(4) and CO(2) by a complex microbial community consisting of hydrolytic, fermenting, syntrophic and methanogenic microorganisms. Here, we investigated which of these microbial groups colonized the rice straw and which were localized in the soil. After incubation of rice straw in anoxic soil slurries for different periods, the straw pieces were removed from the soil, and both slurry and straw were studied separately. Although the potential activities of polysaccharolytic enzymes were higher in the soil slurry than in the straw incubations, the actual release of reducing sugars was higher in the straw incubations. The concentrations of fermentation products, mainly acetate and propionate, increased steadily in the straw incubations, whereas only a little CH(4) was formed. In the soil slurries, on the other hand, fermentation products were low, whereas CH(4) production was more pronounced. The production of CH(4) or of fermentation products in the separated straw and soil incubations accounted in sum for 54-82% of the CH(4) formed when straw was not removed from the soil. Syntrophic propionate degradation to acetate, CO(2) and H(2) was thermodynamically more favourable in the soil than in the straw fraction. These results show that hydrolysis and primary fermentation reactions were mainly localized on the straw pieces, whereas the syntrophic and methanogenic reactions were mainly localized in the soil. The percentage of bacterial relative to total microbial 16S rRNA content was higher on the straw than in the soil, whereas it was the opposite for the archaeal 16S rRNA content. It appears that rice straw is mainly colonized by hydrolytic and fermenting bacteria that release their fermentation products into the soil pore water where they are further degraded to CH(4). Hence, complete methanogenic degradation of straw in rice soil seems to involve compartmentalization.

Benefit-cost analysis of animal identification for disease prevention and control

Individual animal identification is an important consideration for many countries to improve animal traceback systems. The analysis presented by the authors provides a conceptual benefit-cost framework for evaluating the economic usefulness of improved animal identification systems designed to reduce the consequences of foreign animal diseases (FAD). For cattle in situations similar to those found in the United States of America, results show that improved levels of animal identification may provide sufficient economic benefits, in terms of the reduced consequences of FAD, to justify the improvements. In contrast, the results of similar studies in swine show that the economic benefits of the reduced FAD consequences are not sufficient to justify improvements in animal identification systems. Vertically integrated industries, in which animals have only one owner in a closed system from birth to slaughter, may not require individual animal identification for traceback purposes. However, additional benefits, not quantified in this analysis, could contribute to favourable benefit-cost ratios for improved identification in certain sectors of the swine industry.

Effect of botulinum toxin A injections in the treatment of chronic tension-type headache: a double-blind, placebo-controlled trial

In addition to vascular and supraspinal influences, contraction of craniofacial muscles or central sensitization processes following continuous nociceptive input of craniofacial muscles may play an important role in the pathogenesis of tension-type headache. Chemodenervation induced by botulinum toxin injection is successfully used to decrease muscle tension. If muscle tension is important in this type of headache, then botulinum toxin could be helpful in its treatment. We conducted a randomized, placebo-controlled study to examine the effect of 20 U botulinum toxin injected into frontal and temporal muscles in patients with chronic tension-type headache. During a baseline of 4 weeks and a posttreatment period of 8 weeks, the effect was evaluated with daily records and the West Haven-Yale Multidimensional Pain Inventory. Some improvement in affective variables were demonstrated in the botulinum group, but important outcome variables, such as pain intensity, the number of pain-free days, and consumption of analgesics, were not statistically different between the groups. Reasons for these moderate effects may include the injection sites, dose of botulinum toxin, and duration of treatment.

Identification of a cis-acting element and a novel trans-acting factor of the glutamine synthetase gene in liver cells

In the mammalian liver the expression of the enzyme glutamine synthetase (GS) is restricted to a small population of hepatocytes. In cells expressing the enzyme up to 3.5% of total cellular protein is GS. In order to identify enhancer elements contributing to this extraordinarily high level of expression we focused on a region roughly 2.5 kbp upstream of the GS promoter. Gel mobility shift assays revealed binding of an unknown protein within the most distal part of this region and reportergene assays demonstrated that roughly 60 bp downstream from position -2503 are indispensable for protein binding and the full effect of the enhancer. In UV cross-link analysis a 38 kDa nuclear protein that binds to the sequence was identified in rat hepatocytes. This nuclear protein, designated as upstream binding factor of the GS gene (UFGS) seems to play an important role in high-level expression of GS in liver.

Incidence of T wave alternation after acute myocardial infarction and correlation with other prognostic parameters: results of a prospective study

Tachycardia induced alternation of the T wave (TWA) has been associated with arrhythmia morbidity in mixed patient populations. However, less is known concerning the general incidence of TWA and its usefulness in risk stratification early after acute myocardial infarction (MI). TWA was prospectively and systematically assessed in 140 consecutive patients 15 +/- 6 days after acute MI and prior to discharge. Results of TWA measurements were compared to other noninvasive risk markers, LV function, and coronary angiography. Sustained TWA was present at rest or inducible during exercise in 27% of patients. The patient-specific heart rate for the onset of TWA was 98 +/- 9 beats/min. After multivariate analysis, TWA correlated with age (P = 0.02) and LV function (P = 0.002) and occurred more often in patients after nonanterior MI (P = 0.03). Acute results of Holter monitoring, late potentials by signal-averaged ECG, and heart rate variability were unrelated to the TWA status. During follow-up (451 +/- 210 days) two major arrhythmic events occurred. The incidence of TWA early after MI is about 25%. TWA is related to age and LV function but not to other common arrhythmia markers. Although TWA does not appear to be related to excessive cardiac morbidity, evaluation of the prognostic significance of TWA requires further study.

Interferon alfa down-regulates CD81 in patients with chronic hepatitis C

CD81 protein has been shown to bind hepatitis C virus (HCV) envelope 2 (E2) glycoprotein in vitro and may act as a (co)receptor for HCV. Regulation of CD81 expression by interferon alfa (IFN-alpha) and ribavirin could thereby affect the response to antiviral therapy. In the present study, the effects of IFN-alpha and ribavirin on CD81 protein and CD81 mRNA were assessed in peripheral blood lymphocytes (PBL) and isolated human hepatocytes by fluorescence-activated cell sorter (FACS) analysis and real-time polymerase chain reaction (PCR), respectively. In addition, regulation of CD81 in PBL was investigated in 10 patients treated with combination therapy. Incubation with IFN-alpha (50 U/mL) down-regulated total CD81 in PBL (81.7 +/- 11.6% of control; P =.003) and in isolated human hepatocytes (91.6 +/- 8.1% of control; P =.034). Incubation with IFN-alpha with and without ribavirin (2.2 microg/mL) significantly reduced cell surface-associated CD81 protein (83.9 +/- 10.3% of control; P =.003). PBL of untreated patients chronically infected with HCV had significantly higher levels of total CD81 protein compared with PBL obtained from healthy donors (631.1 +/- 93.3 vs. 538.9 +/- 95.2 relative fluorescence units [RFU]; P =.030). Pretreatment cell surface-associated CD81 protein was lower in patients infected with genotype HCV-3 than those infected with HCV-1 (111.8 +/- 15.0 vs. 162.0 +/- 41.3 RFU; P =.019). Furthermore, cell surface-associated CD81 protein was lower 4 weeks after initiation of therapy in patients with an initial virologic response compared with initial virologic nonresponders (110.5 +/- 8.5 vs. 139.8 +/- 27.5 RFU; P =.057). In conclusion, IFN-alpha and ribavirin regulate CD81 expression in vitro and in vivo. CD81 expression correlates with HCV genotype and initial virologic response in patients with chronic hepatitis C.

Functional heterogeneity of ROMK mutations linked to hyperprostaglandin E syndrome

BACKGROUND

The renal K(+) channel ROMK (Kir1.1) controls salt reabsorption in the kidney. Loss-of-function mutations in this channel cause hyperprostaglandin E syndrome/antenatal Bartter syndrome (HPS/aBS), which is characterized by severe renal salt and fluid wasting.

METHODS

We investigated 10 HPS/aBS patients for mutations in the ROMK gene by single-strand conformation polymorphism analysis (SSCA) and direct sequencing. To assess the functional consequences, Ba(2+)-sensitive K(+) currents were measured in five mutants of the core region as well as one mutant with truncated C-terminus, using the two-electrode voltage-clamp technique after an injection of mutant cRNA into Xenopus oocytes.

RESULTS

Three novel ROMK mutations were identified together with six mutations described previously. The mutations were categorized into three groups: (1) amino acid exchanges in the core region (M1-H5-M2), (2) truncation at the cytosolic C-terminus, and (3) deletions of putative promoter elements. While the core mutations W99C, N124K, and I142T led to significantly reduced macroscopic K(+) currents (1 to 8% of wild-type currents), the A103V and P110L variants retained substantial K(+) conductivity (23 and 35% of wild-type currents, respectively). Coexpression of A103V and P110L, resembling the compound heterozygous state of the affected individual, further reduced macroscopic currents to 9% of the wild-type currents. All mutants in the core region exerted a dominant-negative effect on wild-type ROMK1. The C-terminal frameshift (fs) mutation (H354fs) did not change current amplitudes compared with ROMK1 wild type, suggesting that a mechanism other than alteration of the electrophysiological properties may responsible for loss of channel activity.

CONCLUSIONS

Analysis of ROMK mutants linked to HPS/aBS revealed a spectrum of mechanisms accounting for loss of channel function. Further characterization of the molecular defects might be helpful for the development of new therapeutic approaches.

Vascularization of malignant and benign skin tumours measured by D-galactose-based signal-enhanced colour Doppler sonography

PURPOSE

Evaluation of colour Doppler criteria to differentiate between malignant and benign skin tumours on the basis of the degree of vascularization.

MATERIAL AND METHODS

The B-mode sonomorphology and the degree of vascularization in colour Doppler of 81 clinically potentially malignant tumours of cutaneous and subcutaneous structures were analyzed and quantified by number of intratumoral vessels per sonographic slice and percentage vessel area.

RESULTS

Of all criteria employed, counting the intratumoral vessels visible on one ultrasound slice after application of a signal-enhancing agent led to highest sensitivity (94%) of all used criteria but the specificity was poor (64%). The highest specificity (88%) and greatest diagnostic accuracy (86%) discriminating benign and malignant lesions were found using the criterion "percentage vessel area >5.0%" after all inflamed lesions had been excluded on the basis of clinical criteria. Plain colour Doppler increased the specificity up to 97%, although the sensitivity decreased simultaneously to max. 75%. Analysis of the B-mode morphology and spectral Doppler parameter of intratumoral vessels did not contribute to the differential diagnosis.

CONCLUSION

Signal-enhanced colour Doppler sonography is a valuable tool in the pretherapeutic assessment of cutaneous lesions. This method may be relevant for therapy and prognosis.

The electronic structure of the flavin cofactor in DNA photolyase

Density functional theory is used to calculate the electronic structure of the neutral flavin radical, FADH(*), formed in the light-induced electron-transfer reaction of DNA repair in cis,syn-cyclobutane pyrimidine dimer photolyases. Using the hybrid B3LYP functional together with the double-zeta basis set EPR-II, (1)H, (13)C, (15)N, and (17)O isotropic and anisotropic hyperfine couplings are calculated and explained by reference to the electron densities of the highest occupied molecular orbital and of the unpaired spin distribution on the radical. Comparison of calculated and experimental hyperfine couplings obtained from EPR and ENDOR/TRIPLE resonance leads to a refined structure for the FAD cofactor in Escherichia coli DNA photolyase. Hydrogen bonding at N3H, O4, and N5H results in significant changes in the unpaired spin density distribution and hyperfine coupling constants. The calculated electronic structure of FADH(*) provides evidence for a superexchange-mediated electron transfer between the cyclobutane pyrimidine dimer lesion and the 7,8-dimethyl isoalloxazine moiety of the flavin cofactor via the adenine moiety.

Fluvastatin therapy improves microcirculation in patients with hyperlipidaemia

The purpose of this study was to investigate the effect of fluvastatin on the microcirculation of patients with hyperlipidaemia (low-density lipoprotein cholesterol > 160 mg/dL, triglycerides < 350 mg/dl) inadequately controlled by diet. After a dietary run-in of 4 weeks, patients were randomised in a double-blind study to receive fluvastatin 40 mg twice daily (n = 24) or placebo (n = 24) for 12 weeks. The effect on microcirculation was assessed using capillary microscopy and laser Doppler fluxmetry at the nailfold at baseline and at 6 and 12 weeks after initiation of therapy. Capillaroscopy showed that fluvastatin improved microcirculation, i.e. time to peak flow during postocclusive reactive hyperaemia dropped from 19.7 +/- 7.2 s at baseline to 12.3 +/- 9.5 s at week 6 (P < 0.01) and 10.6 +/- 6.5 s at week 12 (P < 0.0001). These results were confirmed using laser Doppler fluxmetry to study microcirculation in thermoregulatory capillaries at the same site. A significant decrease in total and LDL-cholesterol was achieved during fluvastatin therapy. In conclusion, fluvastatin therapy improves microcirculation in nutritive as well as thermoregulatory capillaries in hypercholesterolaemic patients within 6 weeks.

The design and implementation of a restorative care model for home care

PURPOSE

The increasing demand for geriatric home-based care makes it timely to examine how the existing system can become most effective and efficient in promoting the functional outcomes of older patients.

DESIGN AND METHODS

A multidisciplinary work group identified home care agency policies, misconceptions of older adults and their caregivers, and practice patterns of nurses, therapists, and home health aides that can impede patients' progress toward functional independence. This article describes the process that one home care agency used to remove these obstacles.

RESULTS AND IMPLICATIONS

The work group developed and implemented a restorative model of care that integrates the medical treatments for acute disease processes and the personal care and rehabilitative interventions directed toward chronic disabilities, to improve the functional outcomes of older adults receiving home care.

Anomalous elastic response of silicon to uniaxial shock compression on nanosecond time scales

We have used x-ray diffraction with subnanosecond temporal resolution to measure the lattice parameters of orthogonal planes in shock compressed single crystals of silicon (Si) and copper (Cu). Despite uniaxial compression along the (400) direction of Si reducing the lattice spacing by nearly 11%, no observable changes occur in planes with normals orthogonal to the shock propagation direction. In contrast, shocked Cu shows prompt hydrostaticlike compression. These results are consistent with simple estimates of plastic strain rates based on dislocation velocity data.