Sativanine-a and sativanine-b,two new cyclopeptide alkaloids from the bark of Zizyphus sativa

From the bark of Zizyphus sativa, in addition to already described cyclopeptide alkaloids, two new compounds of this class, sativanine-A(1) and sativanine-B(2), were isolated. Both alkaloids contain 14-membered ring systems. 1 belongs to the integerrine type, while 2 is similar to nummularine-G, with an additional ring in the side chain.     

Phylogeny and biogeography of the freshwater crab genus Johora (Crustacea: Brachyura: Potamidae) from the Malay Peninsula, and the origins of its insular fauna

The phylogeny and biogeography of the Malayan freshwater crab genus Johora was studied using two mitochondrial genes, 16S rRNA (560 bp) and cytochrome oxidase subunit I (COI) (616 bp), and one nuclear gene, histone 3 (H3) (328 bp). Johora is shown to be monophyletic and composed of three clades that correspond with the topography of the Malay Peninsula. The three clades were estimated to be of similar age ( c . 11 million years ago (mya)). The Malayan island of Pulau Tioman (with five species) was determined to have been colonised independently by two separate clades (at c . 11 and 5 mya, respectively), one of which evolved semiterrestrial habits, possibly in response to competition by the second. A partitioned Bremer support (PBS) analysis reveals that most of the support for the phylogenetic tree comes from the COI gene fragment and that the nuclear protein-encoding genes H3 is useful for reconstructing the relationships of Johora .     

Sensitivity analysis, molecular systematics and natural history evolution of Scathophagidae (Diptera: Cyclorrhapha: Calyptratae)

The 60 000 described species of Cyclorrhapha are characterized by an unusual diversity in larval life‐history traits, which range from saprophagy over phytophagy to parasitism and predation. However, the direction of evolutionary change between the different modes remains unclear. Here, we use the Scathophagidae (Diptera) for reconstructing the direction of change in this relatively small family (≈ 250 spp.) whose larval habits mirror the diversity in natural history found in Cyclorrhapha. We subjected a molecular data set for 63 species (22 genera) and DNA sequences from seven genes (12S, 16S, Cytb, COI, 28S, Ef1‐alfa, Pol II) to an extensive sensitivity analysis and compare the performance of three different alignment strategies (manual, Clustal, POY). We find that the default Clustal alignment performs worst as judged by character incongruence, topological congruence and branch support. For this alignment, scoring indels as a fifth character state worsens character incongruence and topological congruence. However, manual alignment and direct optimization perform similarly well and yield near‐identical trees, although branch support is lower for the direct‐optimization trees. All three alignment techniques favor the upweighting of transversion. We furthermore confirm the independence of the concepts “node support” and “node stability” by documenting several cases of poorly supported nodes being very stable and cases of well supported nodes being unstable. We confirm the monophyly of the Scathophagidae, its two constituent subfamilies, and most genera. We demonstrate that phytophagy in the form of leaf mining is the ancestral larval feeding habit for Scathophagidae. From phytophagy, two shifts to saprophagy and one shift to predation has occurred while a second origin of predation is from a saprophagous ancestor. © The Willi Hennig Society 2006.     

Surface pretreatment for prolonged survival of cemented tibial prosthesis components: full- vs. surface-cementation technique]

Aseptic loosening of tibial components due to degradation of the interface between bone cement and metallic tibial shaft component is still a persistent problem, particularly for surface-cemented tibial components. The surface cementation technique has important clinical meaning in case of revision and for avoidance of stress shielding. This study was done to prove crack formation in the bone cement near the metallic surface when this is not coated. We propose a newly developed coating process by SiOx-PVD layering to avoid crack formation. A biomechanical model for a vibration fatigue test was done to prove that crack formation can be significantly reduced in the case of coated surfaces. It was found that coated tibial components showed a highly significant reduction of cement cracking near the metal/bone cement interface (p < 0.01) and a significant reduction of gap formation in the metal-to-bone cement interface (p < 0.05). Coating dramatically reduces hydrolytic- and stress-related crack formation at the prosthesis metal/bone cement interface. This leads to a more homogenous load transfer into the cement mantle which should reduce the frequency of loosening in the metal/bone cement/bone interfaces. With surface coating of the tibial component it should become possible that surface-cemented TKAs reveal similar loosening rates as TKAs both surface- and stem-cemented. This would be an important clinical advantage since it is believed that surface cementing reduces metaphyseal bone loss in the case of revision and stress shielding for a better bone health.     

Local nitric oxide levels reflect the degree of allergic airway inflammation after segmental allergen challenge in asthmatics.

Nitric oxide (NO) levels are increased in the exhaled air of asthmatics. As NO levels correlate with allergic airway inflammation, NO measurement has been suggested for disease monitoring. In patients with asthma, we previously demonstrated that intrabronchial treatment with a natural porcine surfactant enhanced airway inflammation after segmental allergen provocation. We studied whether local levels of NO reflect the degree of allergic airway inflammation following segmental allergen challenge with or without surfactant pretreatment. Segmental NO, as well as nitrite and nitrate in bronchoalveolar lavage (BAL) fluid, was measured before and after segmental challenge with either saline, saline plus allergen, or surfactant plus allergen in 16 patients with asthma and five healthy subjects. The data were compared with inflammatory BAL cells. Segmental NO levels were increased after instillation of saline (p < 0.05), or surfactant plus allergen in asthmatics (p < 0.05), and values were higher after surfactant plus allergen compared to saline challenge. Nitrate BAL levels were not altered after saline challenge but increased after allergen challenge (p < 0.05) and further raised by surfactant (p < 0.05), whereas nitrite levels were not altered by any treatment. Segmental NO and nitrate levels correlated with the degree of eosinophilic airway inflammation, and nitrate levels also correlated with neutrophil and lymphocyte numbers in BAL. In healthy subjects, NO, nitrite, and nitrate were unaffected. Thus, segmental NO and nitrate levels reflect the degree of allergic airway inflammation in patients with asthma. Measurement of both markers can be useful in studies using segmental allergen provocation, to assess local effects of potential immunomodulators.     

Two malate dehydrogenases in Methanobacterium thermoautotrophicum

Methanobacterium thermoautotrophicum (strain Marburg) was found to contain two malate dehydrogenases, which were partially purified and characterized. One was specific for NAD⁺ and catalyzed the dehydrogenation of malate at approximately one-third of the rate of oxalacetate reduction, and the other could equally well use NAD⁺ and NADP⁺ as coenzyme and catalyzed essentially only the reduction of oxalacetate. Via the N-terminal amino acid sequences, the encoding genes were identified in the genome of M. thermoautotrophicum (strain ΔH). Comparison of the deduced amino acid sequences revealed that the two malate dehydrogenases are phylogenetically only distantly related. The NAD⁺-specific malate dehydrogenase showed high sequence similarity to l-malate dehydrogenase from Methanothermus fervidus, and the NAD(P)⁺-using malate dehyrogenase showed high sequence similarity to l-lactate dehydrogenase from Thermotoga maritima and l-malate dehydrogenase from Bacillus subtilis. A function of the two malate dehydrogenases in NADPH:NAD⁺ transhydrogenation is discussed. Received: 29 December 1997 / Accepted: 4 March 1998     

Juvenile open angle glaucoma: fine mapping of the TIGR gene to 1q24.3–q25.2 and mutation analysis

Autosomal dominant juvenile open angle glaucoma (JOAG) is an early-onset form of primary open angle glaucoma (POAG), which has been linked to chromosome 1q21–q31. Recently, mutations in the trabecular meshwork inducible glucocorticoid response gene (TIGR), one of the candidate genes mapped in this region, were identified in glaucoma patients of several families. We screened for mutations of the TIGR gene in two German families with JOAG and in 100 unselected sporadic cases of POAG. In the first family we identified a Pro370Leu mutation and in the second family a Gly367Arg mutation cosegregating with the glaucoma phenotype. No pathogenic mutation was found in 100 sporadic cases but a Tyr347Tyr polymorphism was found in two patients. Furthermore, fluorescence in situ hybridization (FISH) analysis was used to map a TIGR-specific yeast artificial chromosome to 1q24.3–q25.2. Received: 19 June 1997 / Accepted: 12 August 1997