Specific acyclic isoprenoids as biological markers of methanogenic bacteria in marine sediments

The widespread occurrence of extended hopanoids in sediments and petroleums illustrates the importance of bacterial lipid contributions to geological materials. In archaebacteria, however, hopanoids are absent; their role as structural components of biomembranes is fulfilled by acyclic isoprenoids. Recent studies of the lipid constituents of archaebacteria have greatly extended the range of acyclic isoprenoid skeletons known in organisms (Fig. 1). In particularly, isoprenoids with head-to-head linkages have been identified, and such compounds (for example, 3,7,11,15,18,22,26,30-octamethyldotriacontane, I) have been recognized in petroleum and as degradation products of Messel shale kerogen. Here we report the first recognition of 2,6,10,15,19-pentamethyleicosane (II), a known component of methanogens, in marine sediments of Recent to Cretaceous age (Table 1) and suggest that it and certain other acyclic isoprenoids may be used as biological markers for methanogens.     

Atypical multicentric reticulohistiocytosis with paraproteinemia

Two women had multiple subcutaneous nodules that showed features of multicentric reticulohistiocytosis (MR). Neither had joint symptoms. Both had a raised erythrocyte sedimentation rate, an immunoglobulin G paraproteinemia, and raised levels of nonhepatic serum alkaline phosphatase. The skin lesions have been followed up, using light and electron microscopy, immunoperoxidase, and histochemical methods. The material in the giant cells stained positively for gamma heavy chain determinants: the light chain type in each case was that of the paraprotein. An attempt to reproduce the skin lesions in one patient by intradermal injection of her paraprotein failed.     

The development of methylcholanthrene-tumors in mice under the environmental influence of various electrobioclimatological conditions (author's transl)

Comparative analyses of the development rate of a slow Tumor (Methylcholanthrene) in mice were undertaken under conditions of a) an electrostatic field (Field strength 200 V/m, Residual sinus component 0.1%), b) a Faraday cage (Shielding effectivity on atmospheric electrical disturbances: 99%) and c) a laboratory, climatized with conventional methods. The tumor was initiated in each case following a 6-week acclimatisation period to the unaccustomed surroundings. Following this, we observed the appearance rates over a period of 8 months at 14-day intervals. Under customary laboratory conditions these were perceptibly higher than in the electrostatic field or in the Faraday cage. No difference was apparent between the two latter conditions. Any variations in the electrobioclimatological environment can lead to stress reactions resulting in familiar consequences to various defense mechanisms. This allows us to find an explanation for the results otherwise difficult to interpret; for both in the electrostatic field and under shielding from external electrical influences the neoplastic activity was obviously reduced in comparison to normally climatized laboratory conditions. We are continuing the experiments.     

Subsolidus Phase Equilibria in the System SrO-B2O3-SiO2

The subsolidus compatibility relations in the system SrO-B₂O₃- SiO₂ were determined by solid-state reaction techniques and X-ray powder diffraction methods. The system was found to contain 11 subsolidus compatibility relations, one stable ternary compound (Sr₃B₂SiO₈), and one metastable ternary compound with a probable composition SrB₂Si₂O₈.     

Comparison of Escherichia coli strains recovered from human cystitis and pyelonephritis infections in transurethrally challenged mice

Urinary tract infection, most frequently caused by Escherichia coli, is one of the most common bacterial infections in humans. A vast amount of literature regarding the mechanisms through which E. coli induces pyelonephritis has accumulated. Although cystitis accounts for 95% of visits to physicians for symptoms of urinary tract infections, few in vivo studies have investigated possible differences between E. coli recovered from patients with clinical symptoms of cystitis and that from patients with symptoms of pyelonephritis. Epidemiological studies indicate that cystitis-associated strains appear to differ from pyelonephritis-associated strains in elaboration of some putative virulence factors. With transurethrally challenged mice we studied possible differences using three each of the most virulent pyelonephritis and cystitis E. coli strains in our collection. The results indicate that cystitis strains colonize the bladder more rapidly than do pyelonephritis strains, while the rates of kidney colonization are similar. Cystitis strains colonize the bladder in higher numbers, induce more pronounced histologic changes in the bladder, and are more rapidly eliminated from the mouse urinary tract than pyelonephritis strains. These results provide evidence that cystitis strains differ from pyelonephritis strains in this model, that this model is useful for the study of the uropathogenicity of cystitis strains, and that it would be unwise to use pyelonephritis strains to study putative virulence factors important in the development of cystitis.     

Potent bicyclic lactam inhibitors of thrombin: Part I: P3 modifications

Peptidomimetic inhibitors of general structure 1 have been prepared. Optimization of the binding affinities of these compounds through variation of the P3 hydrophobic residue is described. Selected substituted bicylic lactams displayed interesting pharmacological profiles both in vitro and in vivo.     

Multiple deletions of the mitochondrial DNA in polymyalgia rheumatica

We analyzed the mitochondrial DNA of patients with polymyalgia rheumatica, a disease frequently associated with mitochondrial myopathy. In an attempt to study the deletions, we have developed a qualitative PCR method using a highly thermostable polymerase in order to amplify multiple mitochondrial DNA large fragments (up to 12 kb). PCR serves to observe both deleted and normal fractions of the mitochondrial DNA. We found multiple deletions of the mitochondrial DNA in all of the patient muscles. Although these muscles harbored many ragged red fibers, we found no point mutations of the tRNA(Leu)(UUR)) and the mutation at nucleotide position 8344 was not present.