Isolation of extremely thermophilic sulfate reducers: evidence for a novel branch of archaebacteria.

Extremely thermophilic archaebacteria are known to be metabolizers of elemental sulfur and the methanogens. A novel group of extremely thermophilic archaebacteria is described, which consists of sulfate-respiring organisms that contain pure factor 420 and that have been isolated from marine hydrothermal systems in Italy. They possess a third type of archaebacterial RNA polymerase structure previously unknown, indicating an exceptional phylogenetic position. Most likely, this group represents a third major branch within the archaebacteria. The existence of sulfate reducers at extremely high temperatures could explain hydrogen sulfide formation in hot sulfate-containing environments, such as submarine hydrothermal systems and deep oil wells.

Antiviral activity of Rhus aromatica (fragrant sumac) extract against two types of herpes simplex viruses in cell culture.

We report on the antiviral potency of an aqueous extract of root/stem bark of Rhus aromatica (fragrant sumac extract) against herpes simplex virus type 1 and type 2 in cell culture (RC-37 cells) using a plaque reduction assay. The extract exhibited a high level of anti-HSV activity with IC50-values of 0.0005% for HSV-1 and 0.0043% for HSV-2 as well as high selectivity indices (SI) of 5400 for HSV-1 and 628 for HSV-2. In order to determine the mode of antiviral action, the fragrant sumac extract was added at different times to the cells or viruses during the viral infection cycle. At maximum non-cytotoxic concentration (0.25%), plaque formation was significantly reduced by more than 99% when herpes simplex viruses were pretreated with the plant extract for 1 h prior to cell infection. When the host cells were pretreated with the fragrant sumac extract for 1 h prior to virus infection, the infectivity of viruses was reduced by 50% for HSV-1 but only moderately for HSV-2. No antiviral effect was seen when the plant extract was added to already infected host cells. Based on these findings the plant extract seems to interact not only with the viral envelope but also with the surface of the host cells impairing the ability of herpes simplex viruses to adsorb to and penetrate into the host cells. In conclusion, the aqueous fragrant sumac extract revealed a strong antiviral activity against HSV-1 and HSV-2 in vitro.

Cytokine secretion: clinical relevance of immunosuppression in non-small cell lung cancer.

Increased production of immunosuppressive IL-10 by non-small cell lung cancer (NSCLC) and increased plasma IL-10 concentrations in NSCLC-patients have recently been correlated to reduced survival. We earlier demonstrated suppression of IL-2 secretion in NSCLC-patients. We now analyzed the influence of IL-2 suppression on survival in NSCLC-patients and influence of IL-10 on IL-2 secretion. The correlation of the IL-2-concentration in whole blood cell cultures from 90 NSCLC-patients at the time of diagnosis to survival was analyzed by using crit-level, the Kaplan-Meier method and the log-rank test. IL-2 secretion capacity at the time of diagnosis significantly influenced survival in NSCLC-patients. With a cut-off value for IL-2 of 1100 pg/ml, the difference in survival was significant with a P-value of 0.014 in the whole patient group. In the subgroup of surgically treated patients (n=33), survival was different with a P-value of 0.011. Moreover, secretion of IL-2 was inhibited in a dose-dependent manner upon addition of IL-10 in whole blood cell cultures from normal individuals. Thus, suppression of IL-2 secretion is predictive for survival of NSCLC-patients and may be mediated by tumor-derived IL-10.

Methanococcus igneus sp. nov., a novel hyperthermophilic methanogen from a shallow submarine hydrothermal system.

A novel hyperthermophilic strictly chemolithoautotrophic member of the genus Methanococcus was isolated from a shallow (depth: 106 m) submarine vent system at the Kolbeinsey ridge, Iceland. The isolate grew between 45 and 91 degrees C with an optimum around 88 degrees C (doubling time: 25 min). It differs from Methanococcus jannaschii in its 16S rRNA sequence, its non-hybridizing DNA, and its selenium-independent growth. Therefore, the isolate represents a new species which we name Methanococcus igneus. Type strain is isolate "Kol 5" (DSM 5666).

Nonradiative and radiative deactivation of singlet molecular oxygen (O2(a1deltag)) in micellar media and microemulsions.

The effects of microheterogeneous media (micelles and microemulsions) on the lifetime and, to our knowledge for the first time, on the emission of singlet molecular oxygen (O2 (a1Ag), denoted as 1O2) were investigated. Micellar media and various types of microemulsions based on anionic (sodiumdodecyl sulfate), cationic (cetyltrimethylammonium chloride) or nonionic (Triton X-100) surfactants were formulated for this purpose. The nonradiative and radiative deactivation rate constants (k(d) and k(e), respectively) were determined in selected microheterogeneous media and in the pure solvents used for their formulation, by combining steady-state and time-resolved 1O2, luminescence detection techniques. We have shown that a simple additive model, as used in homogeneous mixtures of solvents, was inadequate for predicting values of k(d) and k(e) in organized media. In contrast, both 1O2 lifetimes (taudelta = 1/k(d)) and k(e) in the microheterogeneous systems investigated could be predicted with good precision from the composition of the media and the taudelta and k(e) values in the pure solvents, using a two-pseudophase kinetic model for the 1O2 distribution. Such a model takes into account the average times spent by 1O2 in the aqueous and lipophilic pseudo-phases of the organized media, the corresponding equilibrium constant (Keq) depending on the nature of the system.

Evaluation of prenatal intra-amniotic LAMB3 gene delivery in a mouse model of Herlitz disease.

Prenatal gene therapy has been considered for Herlitz junctional epidermolysis bullosa (H-JEB), a lethal genodermatosis caused by the absence of any of the three subunits of laminin-5, resulting from birth in widespread blistering and erosions of skin and mucosae. To investigate this strategy in an animal model, adenovirus type 5- and adeno-associated virus (AAV) type 2-derived vectors carrying a beta-galactosidase reporter gene or LAMB3 cDNA encoding the beta3 chain of laminin-5 were generated, tested for stability in amniotic fluid and evaluated in vitro on murine H-JEB keratinocytes, and in vivo by prenatal injection into the amniotic cavities of laminin-5 beta3-deficient mice. The different vectors were administered individually or combined at maximum doses on day 14 post coitum. Adenoviral vectors infected preferentially the foetal epidermis, whereas AAV delivered the transgene mainly to mucous membranes of the airways and the upper digestive tract. The LAMB3 transgene was expressed in target epithelia of newborn laminin-5 beta3-deficient mice, and the transgenic beta3 chain was shown to assemble with its endogenous partner chains, resulting in detectable amounts of laminin-5 in the basement membranes of skin and mucosae and in a lower extent of tissue separation in the skin. However, only combined delivery of the two vector types led to a minor increase of the life span of H-JEB mice. Failure to rescue diseased animals was, at least in part, due to abandonment of any conspicuous pup by the heterozygous mother. This is the first study of a prenatal gene therapy approach to a heritable blistering disorder. Although our findings indicate that prenatal combined administration of adenoviral and adeno-associated LAMB3 vectors provides therapeutic benefit to H-JEB mice, this animal model appears unsuitable for long-term investigations of the therapeutic concept.

Prognostic significance of cytokine modulation in non-small cell lung cancer.

Increased production of immunosuppressive interleukin-10 (IL-10) by non-small cell lung cancer (NSCLC) and increased serum IL-10 concentrations in NSCLC-patients have recently been correlated to reduced survival. We earlier demonstrated suppression of IL-2 secretion in whole blood cell cultures of NSCLC-patients. We now analyzed the influence of IL-2 secretion on survival in NSCLC-patients and the influence of IL-10 on IL-2 secretion. The correlation of the IL-2 producing ability of whole blood cells in response to PHA in 90 NSCLC-patients at the time of diagnosis to survival was calculated by Crit-level, the Kaplan-Meier method and the log-rank test. With a cut-off value of IL-2 production of 1,100 pg/ml by whole blood cells the difference in survival was significant with a p-value of 0.014. In the group with high and low IL-2, median survival was 14.1 and 9.7 months, respectively. In the subgroup of 33 surgically-treated patients the difference in survival was significant with a p-value of 0.011. In 14 patients with surgical resection of the tumor and high IL-2 at diagnosis and 19 patients with surgical resection, but low IL-2 at diagnosis, median survival was 86.2 and 11.3 months, respectively. Secretion of IL-2 in whole blood cell cultures from healthy individuals was inhibited in a dose-dependent manner upon addition of IL-10. Taken together, suppression of IL-2 secretion has prognostic significance for survival of NSCLC-patients and may be mediated by tumor-derived IL-10.