Antibodies to pollen exines

A polyclonal antiserum and monoclonal antibodies have been prepared to purified pollen exines of Calocedrus decurrens Florin. The location of the antigen is in the exine, as shown by light-and electron-microscopic immunocytochemistry. The greatest reduction in antibody binding follows treatment of the exine with chemicals known to alter sporopollenin. These results provide evidence that sporopollenin is antigenic. Exines of ten species of gymnosperms and angiosperms also bound the polyclonal antiserum, indicating similarity of sporopollenin structure.     

Human papillomavirus infection and cervical intraepithelial neoplasia in women with renal allografts.

An increased prevalence of cervical cancer has been observed in immunosuppressed women, but controlled studies are rare. Biopsy specimens from 49 women with renal allografts and 69 non-immunosuppressed controls (with no history of cervical intraepithelial neoplasia, vulval warts, or abnormal results of cervical smear tests) were assessed for colposcopic appearance, cytological and histological diagnosis, and the presence of human papillomavirus types 6/11 and 16/18 DNA sequences. At colposcopy 26 (53%) of the women with allografts had cervical abnormalities compared with 20 (29%) of the controls. The prevalence of cervical intraepithelial neoplasia was significantly higher in the women with allografts (24 (49%) compared with 7 (10%]. The overall rate of detection of human papillomavirus DNA did not differ significantly between the two groups. There was however, a significant difference in the rate of detection of human papillomavirus type 16/18 DNA (27% in the women with allografts and 6% in the controls). These data confirm that pathological and virological changes affecting the cervix are significantly increased in immunosuppressed women and emphasise the need for regular colposcopic examination.     

Multidrug resistance evaluation by confocal microscopy in primary urothelial cancer explant colonies

Assessing functional multidrug resistance (MDR) status in clinical biopsy material using drug autofluorescence has potential applications to clinical management. The small size of many cystoscopy specimens has led us to develop, as an alternative to flow cytometry, a protocol for studying epirubicin accumulation in adherent colonies of primary bladder cancer cells viewed live andin situ by confocal microscopy. The limitations to quantitation inherent in this technique are compensated for by preservation of cellular organisation and the elimination of non-malignant cells. Biopsy material is disaggregated and explanted into culture-grade petri dishes. After incubation for three to seven days plaques of epithelial cells have developed. Classical patterns of sensitive and resistant drug distribution are observed. Cells of the rolled edges of the colony accumulate more drug than those of the inner epithelial monolayer. Some central areas of larger colonies give the appearance of drug arrested at the intercellular junctions to give a fenestrated pattern. These observations contribute to the understanding of mechanisms in MDR as well as forming the basis for a clinical urological MDR evaluation protocol.     

Neosteinernema longicurvicauda n. gen., n. sp. (Rhabditida: Steinernematidae), a Parasite of the Termite Reticuldermes flavipes (Koller)

A nematode isolated from the termite Reticulitermes flavipes (Koller) was identified and described as a new genus and species, Neosteinernema longicurvicauda. Primary distinguishing characters, by contrast to members of the genus Steinernema, were females having prominent phasmids, a curved tail longer than the body width at the anus, a spiral shape in juvenile-bearing females, and juveniles becoming infective-stage juveniles before emerging from the female; males having prominent phasmids, a digitate tail tip, a characteristic shape of the spicules (foot-shaped with a hump on the dorsal side), and 13-14 pairs of genital papillae, with eight pairs preanal; and infective juveniles having prominent phasmids and a filiform curved tail as long as the esophagus. Adult nematodes are found outside the termite cadaver. Diagnosis of the family Steinernematidae was emended to accommodate the new species.     

Genetic Manipulation of the Cyanobacterium Synechocystis sp. PCC 6803 (Development of Strains Lacking Photosystem I for the Analysis of Mutations in Photosystem II)

We have taken a genetic approach to eliminating the presence of photosystem I (PSI) in site-directed mutants of photosystem II (PSII) in the cyanobacterium Synechocystis sp. PCC 6803. By selecting under light-activated heterotrophic conditions, we have inactivated the psaA-psaB operon encoding the PSI reaction center proteins in cells containing deletions of the three psbA genes. We have also introduced deletions into both copies of psbD in a strain containing a mutation that inactivates psaA (ADK9). These strains, designated D1-/PSI- and D2-/PSI-, may serve as recipient strains for the incorporation of site-directed mutations in either psbA2 or psbD1. The characterization of these cells, which lack both PSI and PSII, is described.     

Field-scale biofiltration of gasoline vapors extracted from beneath a leaking underground storage tank

Approximately 15000 L of unleaded gasoline werereleased into the surrounding vadose zone from aleaking underground storage tank. Initialremediation was by soil vapor extraction andcombustion which soon became cost prohibitive, asadded propane was required to reach the combustionlimit of the extracted vapors. As a cost effectivealternative, a field-scale compost based biofilterwas used in conjunction with soil vapor extractionto remediate the vadose zone. The biofilter wasconstructed on site using 4:1 diatomaceousearth:composted horse manure. Results of a fivemonth study showed that the biofilter removedapproximately 90% of total petroleum hydrocarbons(TPH) and >90% of the BTEX compounds (benzene,toluene, ethylbenzene, xylene), achieving thestringent permit requirements set at either 90% TPHreduction or less than 1.36 kg per day of volatileorganic compounds (VOC's) released to theatmosphere. The biofilter showed the capacity toreadily adapt to changing environmental conditionssuch as increased contaminant loading, andvariations in temperature and moisture. Thebacterial population in the biofilter was uniformlydiverse throughout the biofilter, suggesting that aconsortium of bacteria was needed for efficientbiodegradation. The cost of biofilter set up andoperation saved 90% in the first year alone of theoperating expenses incurred by soil vapor extractionand combustion.     

The pre-steady-state hydrolysis of ATP by porcine brain (Na+ + K+)-dependent ATPase.

The hydrolysis of [gamma-32P]ATP by porcine brain (Na+ + K+)-stimulated ATP phosphohydrolase (EC 3.6.1.3) has been studied at 28 degree C in a rapid mixing quenched-flow apparatus. An "early burst" in the release of Pi from ATP has been observed when the enzyme is mixed with ATP, Na+ and a relatively high concentration of K+ (10 mM) but the burst is less pronounced with 0.5 mM K+. This "early burst" of Pi release is suppressed when the enzyme is pre-mixed with 10 mM K+ or 20% (v/v) dimethylsulphoxide before mixing with ATP and Na+, and premixing of enzyme with Na+ antagonizes this effect of dimethylsulphoxide. The results have been analysed by a non-linear least squares regression treatment and are consistent with a mechanism involving three steps, one of which may be a relatively slow change in enzyme conformation following release of Pi from its covalent linkage with the enzyme, in addition to formation of the enzyme-substrate complex. Rate constants (and S.E.) for these steps have been calculated and the roles of phospho-enzyme and other intermediates in the reaction mechanism of the transport ATPase are dicussed.     

Effect of the Nematode Contortylenchus brevicomi on Gallery Construction and Fecundity of the Southern Pine Beetle

Field-collected Dendroctonus frontalis were reared in a controlled environment. Male-female beetle pairs retrieved from galleries 1, 2, or 5 wk after introduction into pine bolts were examined for nematode parasites. Data were obtained for each pair on gallery length, egg niche construction, egg viability, and progeny survival. In a separate study, beetle pairs were reared under laboratory conditions for 10 wk. The number of emerged adult progeny of each pair was recorded. Contortylenchus brevicomi, a nematode parasite, was found in 25% of all beetles that established galleries. After 2 and 3 wk, female beetles infected with the nematode had produced fewer eggs and shorter galleries than did uninfected females. Uninfected females mated with nematode-infected males showed similar trends, although the differences in the 2- and 3-wk tests were not significant. Progeny survival or egg viability was not affected by nematode parasitism of either parent beetle. Unikaryon minutum, a microsporidian parasite found in 65% of all colonizing beetles, had no effect on measured variables. The lower fecundity of beetles parasitized by C. brevicomi continued throughout the insect''s reproductive cycle. After 10 wk, nematode-infected beetle pairs produced fewer emerged adult progeny than did uninfected pairs.