Three additions of inorganic14Cwere made during midsummer to the mixed layers of two small lake basins in northwestern Ontario. The incorporation of this14Cinto organic matter was monitored, and the ...resulting rates of daily primary production measured in the open water were compared with those derived from bottles incubated both in the laboratory and in situ. Sedimentation of particulate14C, regeneration of inorganic14Cfrom organic14Cfixed on previous days, and time scale were examined as potentially important ways in which the whole-lake method differed from bottle incubations. Daily production estimates derived from laboratory incubations and a numerical model agreed well with whole-lake values. In situ bottle measurements that were analyzed in the standard way consistently underestimated whole-lake values, primarily because of the assumption that solar irradiance (I) is linearly related to integral production (P). Investigators without access to a controlled-light incubator could increase the accuracy of their daily production estimates by calculating P vs. I curves from their in situ production data and analyzing them with the numerical model.
OBJECTIVE--To examine trends in some sexually transmitted diseases in Belgium and to discuss them in the light of the European background. DESIGN--Analysis of the time trends of C trachomatis and N ...gonorrhoeae infections diagnosed by a network of microbiological laboratories, and of male urethritis diagnosed by a network of general practitioners. SETTING--Belgium. SUBJECTS--Reports of C trachomatis and N gonorrhoeae infections by a network of microbiological laboratories, and of male urethritis by a network of general practitioners, to the Institute of Hygiene and Epidemiology. RESULTS--Whereas an increase in the number of C trachomatis infections, more pronounced among women, was observed up to 1986, a small decrease has been observed afterwards in males. The mean number of chlamydial infections per laboratory and per year was 4.2 in 1983, 15.7 in 1986 and 13.9 in 1989. A decrease in the number of N gonorrhoeae infections, more pronounced among men, has been observed. The mean number of cases of gonorrhoea per laboratory and per year was 10.9 in 1983 and only 2.2 in 1989. The same declining trend has been observed in another surveillance programme of male urethritis, based on a network of general practitioners. The number of cases of male urethritis per 100 patient encounters went down from 0.06 in 1982-3 to 0.04 in 1988-9. CONCLUSION--The declining trend in Western Europe in incidence of gonococcal infections and of urethritis in men is also occurring in Belgium, but genital chlamydial infections remain an important public health problem.
We present the results of two sets of experiments designed to express high methionine proteins in transgenic seeds in three different plant species. In the first approach, two chimeric genes were ...constructed in which parts of the Arabidopsis 2S albumin gene 1 (AT2S1) were fused at different positions to a Brazil nut 2S albumin cDNA clone. Brazil nut 2S albumin was found to accumulate stably in transgenic Arabidopsis, Brassica napus, and tobacco seeds. In the second approach, methionine-enriched AT2S1 genes were constructed by deleting sequences encoding a region of the protein which is not highly conserved among 2S albumins of different species and replacing them with methionine-rich sequences. Introduction of the modified AT2S1 genes into three different plant species resulted in the accumulation of the methionine-enriched 2S albumins in all three species at levels reaching 1 to 2% of the total high salt-extractable seed protein
The acyclic nucleoside phosphonate analog 9-(2-phosphonylmethoxyethyl)adenine (PMEA) was recently found to be effective as an inhibitor of visna virus replication and cytopathic effect in sheep ...choroid plexus cultures. To study whether PMEA also affects visna virus infection in sheep, two groups of four lambs each were inoculated intracerebrally with 106.3TCID50of visna virus strain KV1772 and treated subcutaneously three times a week with PMEA at 10 and 25 mg/kg, respectively. The treatment was begun on the day of virus inoculation and continued for 6 weeks. A group of four lambs were infected in the same way but were not treated. The lambs were bled weekly or biweekly and the leukocytes were tested for virus. At 7 weeks after infection, the animals were sacrificed, and cerebrospinal fluid (CSF) and samples of tissue from various areas of the brain and from lungs, spleen, and lymph nodes were collected for isolation of virus and for histopathologic examination. The PMEA treatment had a striking effect on visna virus infection, which was similar for both doses of the drug. Thus, the frequency of virus isolations was much lower in PMEA-treated than in untreated lambs. The difference was particularly pronounced in the blood, CSF, and brain tissue. Furthermore, CSF cell counts were much lower and inflammatory lesions in the brain were much less severe in the treated lambs than in the untreated controls. The results indicate that PMEA inhibits the propagation and spread of visna virus in infected lambs and prevents brain lesions, at least during early infection. The drug caused no noticeable side effects during the 6 weeks of treatment.
With the aim to design potential inhibitors of ribonucleotide reductase (RR), 2′-O-allyl-β-D-arabinofuranosyl-uracil (
4), -cytosine (
7) and -adenosine (
10) were prepared and evaluated for their ...cytostatic activity against Molt4/C8, CEM and L1210 cell lines. Although our preliminary data do not allow to assess if RR is the intracellular target, the results point to differences in the (anti)metabolic behavior of these compounds. This study also offers a general synthesis of 2′-O-allyl-β-D-arabinofuranosyl nucleosides for potential applications in the preparation of 2′-O-allyl-β-D-oligoarabino nucleotides.
The title compounds, designed in view of their potential activity as ribonucletotide reductase (RR) inhybitors, were prepared and tested on Molt4/C8, CEM and L1210 cell lines. The results point to differences in the (anti)methabolic behavior of these compounds.
Optically pure acyclic nucleoside analogues with a 3(S),5-dihydroxypentyl or 4(R)-methoxy-3(S),5-dihydroxypentyl side chain were synthesized starting from 2-deoxy-D-ribose. The acyclic nucleosides ...were obtained by alkylation of the bases with the mesylates 16 and 17. Of these series of novel nucleoside analogues only 9-3(S),5-dihydroxypent-1-ylguanine (6d) showed marked antiviral activity. It inhibited the cytopathogenicity of herpes simplex virus type 1 (HSV-1) at a concentration of 0.4-0.6 microgram/mL, which thus points to a greater antiviral activity than recently reported for the mixture of the R and S enantiomers (12.5 micrograms/mL). In contrast with 6d, its 4(R)-methoxy derivative 7d did not show antiviral activity, which implies that the 4'-methoxy group is unable to mimic the 1',4'-oxygen bridge of the normal furanose ring.
This letter reports the results of the measurement of single photon production in the reaction e(+)e(-) --> gamma+ invisible particles at centre-of-mass energies root s = 130 and 136 GeV and an ...integrated luminosity of 5.83 pb(-1), collected with the DELP
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