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N Weiss

Publications and source records attributed to N Weiss.

At least 73 records · Page 4Linked to original sources

Agrococcus jenensis gen. nov., sp. nov., a new genus of actinomycetes with diaminobutyric acid in the cell wall.

Two strains of a new gram-positive coryneform bacterium isolated from soil and from a sandstone surface are described. Strain 2002-39/1T (T = type strain) is a coccoid, nonmotile, non-acid-fast, microaerophilic organism. The menaquinones of this strain are MK-12 and MK-11, and the main components of the whole-cell sugars are glucose and rhamnose. No mycolic acids are present. The G+C content of the DNA is 74 mol%. Comparative 16S ribosomal DNA studies and a cell wall analysis revealed that this strain represents a new genus belonging to the group of actinomycetes that have diaminobutyric acid in their peptidoglycans. The second strain, strain ST54, which was isolated from a sandstone surface, had the same characteristic features as strain 2002-39/1T. The name Agrococcus jenensis gen. nov., sp. nov., is proposed for these organisms. The type strain is strain 2002-39/1, which has been deposited in the German Collection of Microorganisms and Cell Cultures as strain DSM 9580.

Actinomycetales↗

Anaerofilum pentosovorans gen. nov., sp. nov., and Anaerofilum agile sp. nov., two new, strictly anaerobic, mesophilic, acidogenic bacteria from anaerobic bioreactors.

Strictly anaerobic, gram-positive, nonsporing, thin rod-shaped organisms whose cells were 0.2 to 0.6 by 3 to 6 microns were isolated from a Hoechst Biohochreaktor (strain FaeT [T = type strain]) and from the biofilm population of a fixed-film reactor treating sour whey (strain FT). Strain FT was vigorously motile during early logarithmic growth by means of peritrichously inserted flagella, while strain FaeT was seldom motile and usually possessed no flagella. During the stationary growth phase both strains formed spheroplasts. The temperature optimum was close to 37 degrees C (temperature range for growth, > or = 17 to < 45 degrees C) and the pH optimum was 7.0 to 7.4 (pH range, 6.5 to 8.0) for both strains. The two organisms grew chemoorganotrophically on a number of mono- and disaccharides, including glucose and xylose; yeast extract was required for growth. The principal fermentation products from glucose included lactate, acetate, ethanol, formate, and CO2. Hydrogen was not generated. The G + C contents of the DNAs of strains FaeT and FT were 55 and 54.5 mol%, respectively. The cell wall architecture was typical of gram-positive bacteria; the cells had an extraordinarily thin type A3 alpha' peptidoglycan layer containing muramic acid. Analysis of 16S ribosomal DNA sequences of the two new isolates demonstrated that they represent members of a new genus of bacteria in Clostridium cluster IV of the domain Bacteria and that the misclassified organism Fusobacterium prausnitzii and Clostridium leptum are among their closest relatives. The names Anaerofilum pentosovorans gen. nov., sp. nov. (type strain, strain Fae [= DSM 7168]) and Anaerofilum agile sp. nov. (type strain, strain F [= DSM 4272]) are proposed.

Anaerobiosis↗

Leucobacter komagatae gen. nov., sp. nov., a new aerobic gram-positive, nonsporulating rod with 2,4-diaminobutyric acid in the cell wall.

A new aerobic, gram-positive, nonsporulating rod-shaped organism is described: Strain IFO 15245T (T = type strain) has the following characteristics: the menaquinone contains a side chain with 11 isoprenyl units; the guanine-plus-cytosine content of the DNA is 66.2 mol%; 2,4-diaminobutyric acid, glutamic acid, alanine, glycine, and gamma-aminobutyric acid are present in the cell wall at a molar ratio of ca. 1:1:2:1:1; and glucose and galactose are also present in the cell wall. A comparison of partial 16S rRNA sequences revealed that IFO 15245T represents a distinct line of descent within the gram-positive bacteria with high guanine-plus-cytosine contents. The taxonomic characteristics of this organism are different from those of previously described aerobic, gram-positive, nonsporulating, rod-shaped bacteria. The name Leucobacter komagatae gen. nov., sp. nov., is proposed for this organism. The type strain is strain IFO 15245.

Aminobutyrates↗

Multiplex-PCR-based single-strand conformation polymorphism protocol for simultaneous analysis of up to five fragments of the low-density-lipoprotein receptor gene.

Single-strand conformation polymorphism has become a screening method for the detection of mutations in different genes. For analysis of the promotor region and the coding sequence of the low-density-lipoprotein receptor gene by standard protocols, 21 radiolabeled PCRs and electrophoreses have to be performed. To accelerate this procedure, we developed a nonradioactive multiplex approach of the single-strand conformation polymorphism analysis. Multiplex PCRs were established, each resulting in the amplification of 4 or 5 fragments of this gene. The heat-denatured, single-stranded multiplex-PCR products were electrophoresed, blotted on a nylon membrane and visualized using a chemiluminescence detection system. The simultaneously amplified fragments were clearly resolved by their different mobility on the gel. Comparing the pattern of bands of each separately amplified PCR product and the multiplex-PCR products allowed identification of each band as one exon, part of an exon or the promotor region of the gene. To determine the sensitivity of this method, the low-density-lipoprotein receptor gene of 11 patients with 11 different mutations was analyzed. All mutations could be identified in the multiplex reactions. We conclude that a multiplex-PCR-based, single-strand conformation polymorphism protocol is much faster but equally sensitive compared to standard protocols.

Codon↗

A major allergen of lymphatic filarial nematodes is a parasite homolog of the gamma-glutamyl transpeptidase.

BACKGROUND: Bm2325, a major IgE-inducing antigen of the filarial parasite Brugia malayi has been implicated in the pathology of tropical pulmonary eosinophilia (TPE), a pulmonary syndrome thought to result from hypersensitivity to microfilariae. MATERIALS AND METHODS: Affinity-purified IgE to Bm2325 from patients with TPE was used to identify a complementary DNA (cDNA) from a B. malayi expression library. Sequence analysis of the cDNA revealed a hitherto unknown parasite protein. Immunoblotting of the recombinant filarial protein using sera of patients with TPE determined its IgE-binding capacity. Reactivity to human lung epithelial cell proteins was analyzed using murine anti-Bm2325 antibodies and serum from patients with TPE. RESULTS: The predicted protein is a homolog of the entire precursor of the gamma-glutamyl transpeptidase (gamma-GT), a key enzyme in the synthesis and degradation of glutathione. The filarial precursor encodes both the heavy (H) and the light (L) chain subunits and shares structural similarities with the mammalian enzymes. The Bm2325 allergen was identified as the homolog of the enzyme light chain subunit. Murine antibodies against the recombinant parasite gamma-GT cross-reacted with the human enzyme present in human airway epithelial cells, and human gamma-GT is a target of antibodies present in the serum of patients with TPE. CONCLUSION: Molecular mimicry between the parasite gamma-GT homolog and the host membrane-bound gamma-GT present in lung epithelial cells likely contributes to the pathogenesis observed in tropical pulmonary eosinophilia.

Amino Acid Sequence↗

Onchocerca volvulus: identification and characterization of an immunogenic eggshell protein (Oveg1).

A major antigen recognized by human sera in Onchocerca volvulus infections is a parasite eggshell protein. The cDNA clone for this antigen was isolated from a lambda gt11 O. volvulus cDNA library using antisera from patients with high microfilarial counts. Sequence analysis of the cDNA clone predicts a polyglutamine repeat near the 5' end of the cDNA, and a motif of four arginines near the 3' end, reminiscent of that found in many regulatory proteins. The cDNA was subcloned into a yeast expression vector and reagent quantities of recombinant antigen produced in Saccharomyces cerevisiae. Antisera produced to the recombinant purified protein localized the antigen to the eggshell of developing microfilariae within the adult female uterus. No other sites of Oveg1 expression were noted in adult worms, but labeling was seen in internal membrane structures of L3 larvae. Sera from infected chimps recognized Oveg1 only after infections became patent. Sera from infected humans showed reactivity to Oveg1 that varied from 39 to 95%, depending upon the geographic location.

Amino Acid Sequence↗

Description of human-derived Centers for Disease Control coryneform group 2 bacteria as Actinomyces bernardiae sp. nov.

Biochemical, chemotaxonomic, and molecular methods were used to establish the precise taxonomic position of the Centers for Disease Control (CDC) coryneform group 2 bacteria. The results of a comparative 16S rRNA sequence analysis demonstrated that the CDC coryneform group 2 bacteria constitute a distinct species within the genus Actinomyces. Actinomyces pyogenes was found to be the closest genealogical relative of the CDC coryneform group 2 bacteria, although these taxa were readily distinguished from each other and other Actinomyces spp. by using phenotypic criteria. On the basis of our findings we propose the name Actinomyces bernardiae sp. nov. for the CDC coryneform group 2 bacteria. The type strain is DSM 9152 (CCUG 33419).

Actinomyces↗

Lactosphaera gen. nov., a new genus of lactic acid bacteria, and transfer of Ruminococcus pasteurii Schink 1984 to Lactosphaera pasteurii comb. nov.

The phylogenetic position and physiology of strain KoTa2T (T = type strain), which was previously classified as a Ruminococcus pasteurii strain, were studied. A determination of the 16S ribosomal DNA sequence of this taxon revealed its position within the radiation of the gram-positive lactic acid bacteria having low DNA G+C contents and that it is closely related to the genus Carnobacterium. L-Lactic acid was produced from glucose by a fructose-1,6-bisphosphate-activated lactate dehydrogenase, and oxygen tolerance was observed, characteristics which are consistent with assignment to this group. On the basis of its phenotypic characteristics and unique signature nucleotides, we propose that strain KoTa2 (= DSM 2381 = ATCC 35945) should be transferred to a new genus, Lactosphaera gen. nov., as the type strain of the species Lactosphaera pasteurii comb. nov.

Anaerobiosis↗

Phylogenetic analysis of the genera Cellulomonas, Promicromonospora, and Jonesia and proposal to exclude the genus Jonesia from the family Cellulomonadaceae.

The 16S rRNA gene sequences of eight Cellulomonas species, two Promicromonospora species, and Jonesia denitrificans were determined, and these sequences were compared with the sequences of about 50 representatives of the Arthrobacter line of descent in the order Actinomycetales. We found that in spite of its current assignment to the family Cellulomonadaceae, J. denitrificans branches outside the radiation of this taxon and cannot be considered a member of it. The two Promicromonospora species do not cluster separately from Cellulomonas species and are more closely related to Cellulomonas species than to each other.

Actinomycetales↗

Immunological markers of childhood fevers in an area of intense and perennial malaria transmission.

In order to describe presumed paediatric malaria on a cell-immunological basis, the soluble receptors of IL-2 (sIL-2R) and tumour necrosis factor (sTNF-R55 and sTNF-R75) were quantified in highly exposed young Tanzanian children. Sera were obtained from 66 acute and 72 reported febrile patients during health post consultations and follow-ups and from 68 community controls. Levels of sIL-2R, sTNF-R55 and sTNF-R75 were significantly elevated during fever attacks, especially in very young children. Soluble TNF-R75 levels were most stable and those of sTNF-R55 least. Levels of sTNF-R55 were related to the magnitude of fever and thus appeared to reflect attack severity. Levels of sTNF-R75 were highly significantly associated with parasite density, indicating that this response is malaria-specific. The present study indicates that sTNF-R75 levels could become a useful immunological tool in malaria intervention studies, as they reflect changes in malaria-specific immune responses. Future studies should validate this potential in different endemic settings.

Age Factors↗

Assignment of Actinomyces pyogenes-like (CDC coryneform group E) bacteria to the genus Actinomyces as Actinomyces radingae sp. nov. and Actinomyces turicensis sp. nov.

In a previous study the authors reported the characterization of some facultatively anaerobic, Gram-positive, non-sporeforming rods which were found in mixed cultures from various infectious processes, including patients with otitis, empyema, perianal abscesses and decubitus ulcers. Phenotypically these organisms closely resembled Actinomyces pyogenes although their precise taxonomic position remained unknown. In the present investigation the authors have determined the 16S rRNA gene sequences of some representative strains of the Actinomyces pyogenes-like bacteria and report the results of a comparative sequence analysis. On the basis of the results of the present and earlier findings two new Actinomyces species, Actinomyces radingae sp. nov. and Actinomyces turicensis sp. nov. are proposed. The type strains are DSM 9169T and DSM 9168T, respectively.

Actinomyces↗

Gram-positive cell wall structure of the A3 gamma type in heliobacteria.

The amino acid composition and structure of the peptidoglycan from Heliobacillus mobilis was determined by one- and two-dimensional thin-layer chromatography of completely and partially hydrolysed cell wall preparations. The structure was found to be of the A3 gamma type, with L,L-diaminopimelate in position 3, D-alanine in position 4 and a glycine interpeptide bridge, as found in certain groups of Gram-positive bacteria including Clostridium perfringens and Nocardioides simplex. The presence of a Gram-positive type of cell wall in heliobacteria is consistent with their phylogenetic relationship to the 'low G + C' Gram-positive bacteria, as previously demonstrated by 16S rRNA sequencing.

Amino Acid Sequence↗

Effect of shock waves and cisplatin on cisplatin-sensitive and -resistant rodent tumors in vivo.

The effect of a combination of shock waves with cisplatin was examined in vivo with subcutaneously implanted amelanotic melanomas (A-Mel 3) in Syrian golden hamsters and cisplatin-sensitive or cisplatin-resistant fibrosarcoma (SSK2/0 and SSK2/R2) in C3H mice. In all 3 tumor models, 4 treatment modalities were compared: control, cisplatin treatment, shock waves and the combination of shock waves and cisplatin. Shock waves significantly delayed tumor growth in all 3 tumor models when compared to the respective control group. Cisplatin alone delayed the growth of A-Mel 3 and SSK2/0, whereas SSK2/R2 remained uninfluenced by the drug. In all 3 tumor models the combined treatment with shock waves and cisplatin additively and significantly delayed tumor growth. In A-Mel-3-bearing animals the combined treatment significantly increased survival time. The growth of SSK2/0 and SSK2/R2 tumors was delayed to a similar extent by the combined treatment modality as compared to shock-wave treatment alone. This indicates that the cisplatin resistance of SSK2/R2 tumors has been overcome by the simultaneous shock wave treatment. An increased intracellular cisplatin accumulation in the tumors due to shock wave exposure is suggested as the mechanism of interaction between shock waves and cisplatin.

Animals↗

Effect of social networks on cancer-screening behavior of older Mexican-American women.

BACKGROUND: Previous studies have determined that Hispanic women and, in particular, Mexican-American women have the lowest rates of cancer screening of any race and ethnic group in the United States. In the development of cancer control strategies for this population, little attention has been given to factors that encourage Mexican-American women to seek cancer preventive care. Recent studies suggest that social networks can have a positive influence on cancer-screening participation. PURPOSE: We determined the extent to which differences in social networks account for variations in breast and cervical cancer-screening practices among low-income Mexican-American women. METHODS: The data analyzed in this study were obtained from a baseline survey of knowledge, attitudes, and cancer-screening practices conducted prior to implementation of community interventions designed to improve Pap smear and mammography screening in low-income Mexican-American women 40 years old and older living along the U.S.-Mexican border in El Paso County, Texas. A random selection of 1300 households served as a sampling frame to identify Mexican-American women 40 years old and older for personal interviews. Of the 549 households identified as having at least one eligible female, 450 women completed the personal interviews that provided the data for this study. Personal interviews solicited information on age, income, marital status, place of birth, education, health insurance coverage, Pap smear- and mammogram-screening practices, and six questions relating to social network. A social network score was assigned to each woman by summation of the following six variables: number of confidants, number of close friends, number of close relatives, frequency of contact with these close friends or relatives per month, church membership, and church attendance. Women were grouped into three linear strata of social network (low, medium, high) based on tertiles of the scores. Cancer-screening history was also ascertained during the interview. RESULTS: The 2-year prevalence of Pap smear and mammography use increased with social network. For each gain in social network level (low, medium, high), adjusted for sociodemographic factors, the odds ratio for Pap smear use was 1.33 (95% confidence interval = 1.02-1.73); it was 1.40 (95% confidence interval = 1.02-1.93) for mammogram use. Of the six social network components, the number of close friends was the most important predictor of mammography (P = .002) and Pap smear (P = .025) screening. CONCLUSION: Social networks appear to be an important determinant of cancer-screening behavior among low-income, older Mexican-American women.

Adult↗