Adverse events during treatment of critical limb ischemia with autologous peripheral blood mononuclear cell implant.

AIM: Trials have reported clinical improvement and reduced need for amputation in critical limb ischemia (CLI) patients receiving therapeutic angiogenesis with stem cells. Our objective was to test peripheral stem cell therapy efficacy and safety to gain experiences for further work. METHODS: We included nine CLI patients (mean age 76.7 ±9.7). Stem cells were mobilized to the peripheral blood by administration of G-CSF (Filgrastim) for 4 days, and were collected on day five, when 30 mL of a stem cell suspension was injected into 40 points of the limb. The clinical efficacy was evaluated by assessing pain relief, wound healing and changes in ankle-brachial pressure index (ABI). Local metabolic and inflammatory changes were measured with microdialysis, growth factors and cytokine level determination. Patients were followed for 24 weeks. RESULTS: Four patients experienced some degree of improvement with pain relief and/or improved wound healing and ABI increase. One patient was lost to follow up due to chronic psychiatric illness; one was amputated after two weeks. Two patients had a myocardial infarction (MI), one died. One patient died from a massive mesenteric thrombosis after two weeks and one died from heart failure at week 11. Improved patients showed variable effects in cytokine-, growth factor- and local metabolic response. CONCLUSION: Even with some improvement in four patients, severe complications in four out of nine patients, and two in relation to the bone marrow stimulation, made us terminate the study prematurely. We conclude that with the increased risk and the reduced potential of the treatment, peripheral blood stem cell treatment in the older age group is less appropriate. Metabolic and inflammatory response may be of value to gain insight into mechanisms and possibly to evaluate effects of therapeutic angiogenesis.

Experiences with the new genetic variant of Chlamydia trachomatis in Orebro county, Sweden - proportion, characteristics and effective diagnostic solution in an emergent situation.

A Chlamydia trachomatis variant that contains a 377 bp deletion in the cryptic plasmid was recently reported in Sweden. This deletion includes the targets for Cobas Amplicor, Cobas TaqMan48, and Abbott m2000. We examined the proportion and characteristics of this variant in Orebro county, Sweden and developed an effective diagnostic solution. In total, 2,401 consecutive C. trachomatis culture samples and 536 PCR samples from symptomatic and asymptomatic patients and screened females were included. Culture, Cobas Amplicor, and LightMix 480HT were used for diagnosis. A mutant-specific PCR, plasmid sequencing, omp1 sequencing and multilocus sequence typing (MLST) were used to identify and characterise mutants. In total, 162 (6.7%) of the cultured samples were positive for C. trachomatis. However, 61 (38%) of those were negative when using Cobas Amplicor, and 60 of these were subsequently confirmed as the new variant. 13 of these mutant isolates were further characterised genetically, and all were of identical genotype E and the unique MLST sequence type: 21, 19, 1, 2, 1. Of all culture-positive samples, 161 of 162 were positive in the LightMix 480HT assay. The single negative sample was only weakly positive in culture, and negative in all PCRs. Of the 536 PCR samples, 37 were positive in both Cobas Amplicor and LightMix 480HT, 13 were only positive in LightMix 480HT (mutants), and two were only positive in Cobas Amplicor. Mutated C. trachomatis were prevalent in Orebro county in the period from October 2006 to February 2007, and it appeared to be a single clone. LightMix 480HT seemed sensitive, specific, and enabled high throughput diagnostics. However, rare low positive samples may be false-negative. Frequent surveillance and evaluations of diagnostic methods worldwide are crucial.

Similar inflammatory response in human whole blood to live Streptococcus pneumoniae of different serotypes.

Differences in inflammatory responses in human adult whole blood to live pneumococcal serotypes 3, 7F, 9V and 23F were investigated. Using flow cytometry and ELISA, oxidative burst, expression of activation markers CD11b/CD18, and in-vitro production of tumour necrosis factor-alpha, interleukin-6 (IL-6) and interleukin-8 were measured. There was no significant difference between the serotypes regarding any of the variables investigated, although there was a trend towards higher concentrations of IL-6 induced by serotypes 9V and 23F. In the present experimental model, the serotypes of Streptococcus pneumoniae shown previously to cause different degrees of inflammation were found to cause a similar inflammatory response in human whole blood.

Characterization of Chlamydia trachomatis omp1 genotypes among sexually transmitted disease patients in Sweden.

A method for detection and genotyping of genital Chlamydia trachomatis infections based on omp1 gene amplification and sequencing was developed. DNA was extracted from urogenital or urine samples using a Chelex-based method, and an approximately 1,100-bp-long fragment from the omp1 gene was directly amplified and sequenced. Genotyping was performed by BLAST similarity search, and phylogenetic tree analysis was used to illustrate the evolutionary relationships between clinical isolates and reference strains. The method was used to determine the genotypes of C. trachomatis in 237 positive urogenital and/or urine specimens collected at a Swedish sexually transmitted disease clinic during 1 year. The most common genotypes corresponded to serotypes E (47%) and F (17%). The omp1 gene was highly conserved for genotype E (106 of 112 samples without any mutation) and F (41 of 42 samples without any mutation) strains but appear slightly less conserved for genotypes G (n = 6) and H (n = 6), where the sequences displayed one to four nucleotide substitutions relative to the reference sequence. Genotyping of samples collected at the follow-up visit indicated that two patients had become reinfected, while three other patients suffered treatment failure or reinfection. One woman appeared to have a mixed infection with two different C. trachomatis strains. This omp1 genotyping method had a high reproducibility and could be used for epidemiological characterization of sexually transmitted Chlamydia infections.

Inhibition of nonopsonic Helicobacter pylori-induced activation of human neutrophils by sialylated oligosaccharides.

Certain strains of Helicobacter pylori have nonopsonic neutrophil-activating capacity. Some H. pylori strains and the neutrophil-activating protein of H.pylori (HPNAP) bind selectively to gangliosides of human neutrophils. To determine if there is a relationship between the neutrophil-activating capacity and the ganglioside-binding ability, a number of H. pylori strains, and HPNAP, were incubated with oligosaccharides, and the effects on the oxidative burst of subsequently challenged neutrophils was measured by chemiluminescence and flow cytometry. Both by chemiluminescence and flow cytometry a reduced response was obtained by incubation of H.pylori with sialic acid-terminated oligosaccharides, whereas lactose had no effect. The reductions obtained with different sialylated oligosaccharides varied to some extent between the H. pylori strains, but in general 3'-sialyllactosamine was the most efficient inhibitor. Challenge of neutrophils with HPNAP gave no response in the chemiluminescence assay, and a delayed moderate response with flow cytometry. Preincubation of the protein with 3'-sialyllactosamine gave a slight reduction of the response, while 3'-sialyllactose had no effect. The current results suggest that the nonopsonic H. pylori-induced activation of neutrophils occurs by lectinophagocytosis, the recognition of sialylated glycoconjugates on the neutrophil cell surface by a bacterial adhesin leads to phagocytosis and an oxidative burst with the production of reactive oxygen metabolites.

Nonopsonic activation of neutrophils by Helicobacter pylori is inhibited by rebamipide.

Some clinical isolates of nonopsonized H. pylori have the ability to activate neutrophils to an oxidative burst (neutrophil activating capacity, NAC), and such strains were significantly more often isolated from patients with peptic ulcer disease and active chronic gastritis. The purpose of the present work was to investigate the effect of rebamipide (Mucosta) on the release of reactive oxygen metabolites from neutrophils activated by various strains of H. pylori with or without NAC, nonopsonized or opsonized, using as controls fMLP and PMA, known activators of neutrophils, and to study the kinetics of these events by luminol-enhanced chemiluminescence and by flow cytometry. The results showed that the oxidative burst induced in neutrophils by fMLP and by nonopsonized or opsonized H. pylori with NAC was inhibited by rebamipide in a dose-dependent manner both in the early and late phases of activation. In contrast, the oxidative burst induced by opsonized H. pylori without NAC was not inhibited by rebamipide, which might indicate that it does not have the ability to block CR1 or CR3 receptors involved in opsonic phagocytosis but still has the ability to block the receptor(s) for NAC. The oxidative burst induced by PMA, which primarily activates protein kinase C, was not inhibited in the early phase but diminished 40-45% in the late phase with the 2 mM concentration of rebamipide, probably due to scavenging of reactive oxygen species. In conclusion, rebamipide has the ability to diminish the oxidative burst of neutrophils activated by nonopsonized or opsonized H. pylori organisms with neutrophil activating capacity, most likely through the blocking of fMLP-related receptors, inhibition of the production of reactive oxygen species, and the scavenging of such metabolites. Rebamipide may therefore be useful to prevent gastroduodenal lesions associated with gastric mucosal inflammation in H. pylori infection.

Adhesion to and invasion of HeLa cells by Helicobacter pylori.

Eight clinical isolates and two reference strains of Helicobacter pylori were studied with regard to their interactions with HeLa cells. All the isolates adhered poorly to HeLa cells and the number of invasive bacteria was very low. No correlation was found between the adherence and invasiveness of the isolates on one hand, and the corresponding patients having ulcer or non-ulcer disease, or the ability of the strains to produce cytotoxin and to induce an oxidative burst of human polymorphonuclear leukocytes without opsonins, on the other. These results indicate that invasion of epithelial cells would play no important role in the pathogenesis of infections caused by H. pylori.