Cervical cancer isolate PT3, super-permissive for adeno-associated virus replication, over-expresses DNA polymerase δ, PCNA, RFC and RPA

Background  

Adeno-associated virus (AAV) type 2 is an important virus due to its use as a safe and effective human gene therapy vector and its negative association with certain malignancies. AAV, a dependo-parvovirus, autonomously replicates in stratified squamous epithelium. Such tissue occurs in the nasopharynx and anogenitals, from which AAV has been clinically isolated. Related autonomous parvoviruses also demonstrate cell tropism and preferentially replicate in oncogenically transformed cells. Combining these two attributes of parvovirus tropism, squamous and malignant, we assayed if AAV might replicate in squamous cervical carcinoma cell isolates.     

Mechanism of Copper Resistance in a Copper Mine Isolate Pseudomonas putida Strain S4

The mechanism of copper resistance in a multiple-metal-resistant natural isolate Pseudomonas putida strain S4 is based on inducible efflux. Active extrusion of copper ions occurs from the cytoplasm during the exponential phase of growth. Involvement of ATPase in the efflux of copper ions has been demonstrated by employing specific inhibitors. The effluxed copper is not thrown out of the cell, but remains in a bound form (to a protein) in the periplasm. Thus, a balance between the intracellular level, to fulfill the metabolic requirements, and the periplasmic sequestration, to evade toxicity, is maintained by this isolate. Received: 11 February 2002 / Accepted: 7 March 2002     

Correction to: Combined therapeutic efficacy of carvacrol and X-radiation against 1,2-dimethyl hydrazine-induced experimental rat colon carcinogenesis

Molecular and Cellular Biochemistry -     

Quantitative estimation of islet tissue of pancreas in adult Grey kangaroos (Macropus fuliginosus)

Six Grey kangaroos, both male and female, were shot and weighed. The pancreas was isolated, weighed and samples fixed in Bouin's solution. Using a linear scanning technique (Carpenter & Lazarow, 1962) the mean islet tissue mass was estimated in head, neck, body and tail regions. A uniform distribution was found in all regions. The relationship between pancreas weight and body weight and islet mass in relation to body weight were calculated. Sections stained with aldehyde-fuchsin (Gomori, 1950), Mallory's phosphotungstic acid haemotoxylin and modified Davenport's technique (Epple, 1967) were prepared. Using a Wild-M501 semiautomatic sampling microscope and a Weibel graticule (Weibel et al., 1966) the percentage volume of β cells, α cells and δ cells were estimated respectively in the head, neck, body and tail regions of the six samples. The α cells or glucagon-producing cells were the most predominant as these macropodid marsupials are well adapted to dealing with hypoglycemic conditions. They were uniformly distributed in all regions.     

Elements of disturbance that affect epiphyte vitality in a temperate rainforest: an experimental approach

Aims Epiphytes are an abundant and diverse component of many wet temperate forests and have significant roles in ecosystem processes. Little is known about the processes and rates of their death and decomposition when they fall from the canopy, which limits our understanding of their role in forest carbon sequestration and nutrient cycling. In the temperate rainforest of the Quinault River Valley, Washington State, our aim was to test hypotheses regarding four elements of disturbance that might contribute to their decline.     

Biosynthesis of hexamannophosphoinositides inMycobacterium smegmatis ATCC 607

The biosynthesis of hexamannophosphoinositides inMycobacterium smegmatis ATCC 607 was examined using labelled tri- and tetraacylated dimannophosphoinositides (PIM₂-3F and PIM₂-4F) as precursors, byin vivo andin vitro incorporation. Tetraacylated dimannoside was metabolically more active as compared to triacylated dimannoside and seems to be the precursor for the synthesis of hexamannophosphoinositides.Abbreviations M. 607 Mycobacterium smegmatis ATCC 607 - PIMs Mannophosphoinositides - PIM₂-2F diacylated dimannoside - PIM₂-3F triacylated dimannoside - PIM₂-4F tetraacylated dimannoside - PIM₃-3F triacylated trimannoside - PIM₆-3F triacylated hexamannoside - PIM₆-4F tetraacylated hexamannoside - GDP-mannose Guanosine diphosphomannose     

Isolation and characterization of cDNAs encoding beta A2- and beta A4-crystallins: heterologous interactions in the predicted beta A4-beta B2 heterodimer

Except for the two acidic chains, beta A2 and beta A4, the primary structures of all bovine beta-crystallins have previously been elucidated, either by direct protein sequencing or prediction from cDNA sequencing. Both beta A2 and beta A4 were found to be synthesized in half-year-old calf lenses and are therefore likely to be present in a cDNA bovine library constructed from mRNA isolated from lenses of that age. A large number of cDNA clones was screened with all available crystallin, actin, vimentin and lens membrane protein MP26 probes and finally with a randomly primed mRNA probe. Clones positive for the latter, but negative for known lens proteins, were isolated and sequenced. beta A2, comprising 197 aa, and beta A4, comprising 209 aa, were identified. Both proteins have a conserved two-domain structure and an N-terminal extension which is variable. A three-dimensional model of the structure of beta A4 was made based on the coordinates of one subunit from the beta B2 dimer which has recently been solved using x-ray diffraction techniques. The resulting heterodimer structure, together with the compiled bovine beta-crystallin sequences, was used to indicate those regions of the sequences which distinguish acidic from basic beta-crystallins with a view to defining structural features necessary for subunit recognition in beta-crystallin aggregates. With the aid of the present data, the complete evolutionary tree of the bovine beta-crystallin family has been constructed, which confirms the early separation of the genes encoding the three acidic and the three basic beta-crystallins.     

Proteolytic Cleavage of Type I Collagen Generates an Autoantigen in Autoimmune Uveitis

This study was initiated to induce experimental autoimmune anterior uveitis (EAAU) in Lewis rats by melanin-associated antigen (MAA; 22-kDa fragment of type I collagen α2 chain) derived from rat iris and ciliary body (CB), to localize MAA within the eye, and to investigate the possible mechanism of MAA generation in vivo. The EAAU model replicates idiopathic human anterior uveitis. Lewis rats sensitized to rat MAA developed anterior uveitis, and EAAU induced by rat MAA can be adoptively transferred to naive syngenic rats by MAA-primed T cells. Animals immunized with rat MAA developed cellular immunity to the antigen. MAA was detected only in the iris and CB of the eye. Iris and CB were the major source of matrix metalloproteinase-1 (MMP-1) in the naive eye, and ocular expression of MMP-1 was up-regulated, whereas expression of tissue inhibitor of metalloproteinase 1 decreased before the onset of EAAU. These results demonstrated that EAAU can be induced by autologous MAA. Uveitogenic antigen is present only in the iris and CB of the eye, and the imbalance between MMP-1 and tissue inhibitor of metalloproteinase 1 may play a role in the generation of MAA in vivo. Collectively, the evidence presented here suggests that MAA is an autoantigen in EAAU. These observations may extend to idiopathic human anterior uveitis and facilitate the development of antigen-specific therapy.