The rainbow cohort: 96 week follow-up of saquinavir-containing regimens in previously antiretroviral therapy (ART)-naive and pre-treated but protease inhibitor (PI)-naive HIV-infected patients.

OBJECTIVE: We have previously reported data from the German cohort of the multinational observational prospective RAINBOW survey which assessed the tolerability and efficacy of ritonavir-boosted saquinavir (SQV/r)-containing regimens over 48 weeks in routine clinical practice. This analysis presents data from antiretroviral (ART)-naive and pretreated but protease inhibitor (PI)-naive patients treated in a long-term one line (96 weeks) follow-up of the initial study. METHODS: All ART- and PI-naive patients from the initial RAINBOW cohort who had recorded data to one line 96 weeks of treatment were eligible for inclusion in the current analysis. Efficacy assessments included the proportion of patients with HIV-1 RNA <50 and <400 copies/mL and changes in CD4 cell count from baseline to week 96. Tolerability assessments included changes in liver enzymes and lipid levels from baseline to week 96. For evaluation of efficacy, intent-to-treat analysis, in which missing values were recorded as failure (ITT), and last-observation-carried-forward (LOCF) analysis were used. Metabolic parameters were assessed using LOCF analysis. RESULTS: The analysis included 175 ART-naive and 109 pretreated but PI-naive patients. After 96 weeks, a similar proportion of patients in the ART-naive and in the pretreated but PI-naive group had HIV-1 RNA levels <400 copies/mL (68.0% and 70.6% [ITT], respectively; 96.6% and 90.8% [LOCF], respectively). The proportion of patients with HIV RNA <50 copies/mL was higher in the ART-naive group compared with the pretreated but PI-naive group (61.1% and 56.9% [ITT], respectively; 84.0% and 75.2% [LOCF], respectively). Median change in CD4 cell count from baseline to week 96 was +263 cells/mm3 (IQR 170; 384. LOCF; p<0.0001) in the ART-naive group, and one line +181 cells/mm3 (IQR 60; 309. LOCF; p<0.0001) in the pretreated but PI-naive group. Treatment was well tolerated, with only 2.5% of patients withdrawing from treatment due to side effects. There were no clinically relevant changes in liver enzyme levels. Overall total cholesterol, triglyceride, and low- and high-density lipoprotein levels increased to week 96, although levels remained within normal ranges in the majority of ART-naive and pretreated patients. CONCLUSIONS: This follow-up analysis confirms the long term efficacy and tolerability of SQV/r in ART-naive and pretreated but PI- naive patients in the real-life clinical setting.

Safety and efficacy after switch to a saquinavir-containing antiretroviral regimen in protease inhibitor pretreated HIV-positive patients.

OBJECTIVE: the RAINBOW survey is a multinational observational study assessing the tolerability and efficacy of ritonavir-boosted saquinavir (SQV/r), using the 500 mg film-coated SQV formulation, in routine clinical practice. This analysis presents data from the German subgroup of protease inhibitor (PI)-pretreated, but SQV-naive patients. METHODS: multicenter, prospective, open-label, 48 week cohort study. Efficacy assessments included the proportion of patients with HIV-1 RNA <50 and <400 copies/mL and changes in CD4 cell count from baseline to week 48. Tolerability assessments included changes in liver enzymes and lipid levels from baseline to week 48. RESULTS: a total of 426 patients were included in the analysis. The proportion of patients with HIV RNA levels <50 copies/mL at week 48 was 60.3 % (compared with 31.7% at switch to SQV/r) (intent-to-treat, last observation carried forward analysis). After 48 weeks, median CD4 count increased by +61 cells/mm3 from baseline (p<0.01) and 60.3% of patients achieved HIV-1 RNA <50 copies/mL. Median changes in fasting triglyceride levels (stratified according to baseline level) at week 48 were: +14 mg/dL (IQR -8; 57) for patients with baseline triglyceride <200 mg/dL; -50 mg/dL (IQR -139; 0) for baseline triglyceride 200-750 mg/dL, and -656 mg/dL (IQR -1024; 0) for baseline triglyceride >750 mg/dL (p<0.01 for all). Median changes in fasting total cholesterol (TC) levels (stratified according to baseline) were +16 mg/dL (IQR -3; 43) for patients with baseline TC <200 mg/dL (p<0.01), -3 mg/dL (IQR -25; 25) for baseline TC 200-300 mg/dL (p = 0.4), and -47 mg/dL (IQR -87; -4) for baseline TC >300 mg/dL (p<0.01). No significant changes in liver enzymes or bilirubin were observed. SQV treatment was discontinued in 22% of patients, 6% due to side effects. CONCLUSIONS: these data confirm the efficacy and tolerability of SQV/r in PI-experienced, SQV-naive patients treated in a real-life clinical setting. Of particular relevance are the improvements in triglycerides and TC levels observed in patients with baseline grade III-IV elevations.

Safety and efficacy of a saquinavir-containing antiretroviral regimen in previously ART-naïve or pretreated but protease inhibitor-naïve HIV-positive patients.

BACKGROUND: The RAINBOW survey is a multinational observational study assessing the tolerability and efficacy of ritonavir-boosted saquinavir (SQV/r), using the 500-mg film-coated SQV formulation, in routine clinical practice. This analysis presents data from the German subgroup of antiretroviral therapy (ART)-naïve and pretreated but protease inhibitor (PI)-naïve patients. METHODS: This was a multicenter, prospective, open-label, 48-week observational cohort study. Tolerability assessments included changes in liver enzymes and lipid levels from baseline to week 48. Efficacy assessments included changes in the proportion of patients with HIV-1 RNA <50 and <400 copies/ml, and changes in CD4 cell count from baseline to week 48. RESULTS: The analysis included 275 ART-naïve and 179 pretreated but PI-naïve patients. The proportion of ART-naïve patients achieving <50 copies/ml by 48 weeks was 53.1% by intent-to-treat (ITT) analysis and 67.3% using last observation carried forward (LOCF) analysis. In pretreated but PI-naïve patients, the proportions achieving <50 copies/ml by 48 weeks were 53.1% (ITT) and 70.4% (LOCF). The median increase in CD4 count at week 48 was +174 cells/mm3 (interquartile range [IQR] 86, 265) in the ART-naïve group and +100 cells/mm3 (IQR 0, 209) in the pretreated but PI-naïve group (p < 0.01 for both; LOCF). Drug-related adverse events were reported in 7.6% of ART-naïve and 2.8% of pretreated but PI-naïve patients. Treatment with SQV/r was stopped in 21.5% of ART-naïve and 17.9% of pretreated but PI-naïve patients (due to side effects in 3.3% and 2.8%, respectively). There were no clinically relevant changes in liver enzyme levels. Overall, the total cholesterol, triglyceride, low-density lipoprotein, and high-density lipoprotein levels increased to week 48, although the levels remained within normal ranges in the majority of patients. CONCLUSIONS: The results of this observational cohort study of treatment with the 500-mg tablet formulation of SQV are consistent with high efficacy and tolerability results seen in controlled studies of SQV/r. This analysis confirms that SQV/r is effective and well tolerated in ART-naïve and pretreated but PI-naïve patients in 'real-world' clinical settings.

Assay of DNA photolyase activity in spinach leaves in relation to cell compartmentation-evidence for lack of DNA photolyase in chloroplasts.

Spinach cyclobutane pyrimidine dimer (CPD)-specific DNA photolyase was successfully detected in leaf extracts by an assay system for plant photolyase using an improved enzyme-linked immunosorbent assay (ELISA) which was newly introduced by novel horseradish peroxidase (HRP)-linked CPD specific monoclonal antibodies. The assay system includes two main steps: a photorepair reaction of CPD introduced in substrate DNA and measurement of CPD remained after the photorepair by the improved ELISA. When CPD- induced salmon sperm DNA was used as a substrate, high CPD-photolyase activities were observed in the enzyme fraction prepared from whole spinach leaf extracts, but not from chloroplast extracts. This strongly suggests that spinach CPD-specific photolyases are localized in cell compartments other than chloroplasts.

The cell wall-anchored Streptomyces reticuli avicel-binding protein (AbpS) and its gene.

Streptomyces reticuli produces a 35-kDa cellulose-binding protein (AbpS) which interacts strongly with crystalline forms of cellulose (Avicel, bacterial microcrystalline cellulose, and tunicin cellulose); other polysaccharides are recognized on weakly (chitin and Valonia cellulose) or not at all (xylan, starch, and agar). The protein could be purified to homogeneity due to its affinity to Avicel. After we sequenced internal peptides, the corresponding gene was identified by reverse genetics. In vivo labelling experiments with fluorescein isothiocyanate (FITC), FITC-labelled secondary antibodies, or proteinase K treatment revealed that the anchored AbpS protrudes from the surfaces of the hyphae. When we investigated the hydrophobicity of the deduced AbpS, one putative transmembrane segment was predicted at the C terminus. By analysis of the secondary structure, a large centrally located alpha-helix which has weak homology to the tropomyosin protein family was found. Physiological studies showed that AbpS is synthesized during the late logarithmic phase, independently of the carbon source.

Ultraviolet Light Inhibition of Phytochrome-Induced Flavonoid Biosynthesis and DNA Photolyase Formation in Mustard Cotyledons (Sinapis alba L.).

In cotyledons of etiolated mustard (Sinapis alba L.) seedlings, phytochrome-far-red-absorbing form-induced flavonoid biosynthesis was found to be inhibited by short-term ultraviolet (UV) irradiations. UV inhibition was shown for the synthesis of quercetin, anthocyanin, and also for the accumulation of the mRNA for chalcone synthase, the key enzyme of this pathway. The UV effect was more pronounced on flavonoid biosynthesis, a process that selectively occurs in the epidermal layers, than on the synthesis of mRNA for chlorophyll a/b-binding protein localized in the mesophyll tissue. These UV inhibitory effects were accompanied by cyclobutane pyrimidine dimer (CPD) formation showing a linear fluence-response relationship. CPD formation and UV inhibition of flavonoid biosynthesis was found to be partially reversible by blue/UV-A light via DNA photolyase (PRE), allowing photoreactivation of the DNA by splitting of CPDs, which are the cause of the UV effect. Like flavonoid formation PRE was also induced by the far-red-absorbing form of phytochrome and induction was inhibited by UV. A potential risk of inhibition, in response to solar UV-B irradiation, was shown for anthocyanin formation. This inhibition, however, occurred only if photoreactivation was experimentally reduced. The PRE activity present in the etiolated seedlings (further increasing about 5-fold during light acclimatization) appears to be sufficient to prevent the persistence of CPDs even under conditions of high solar irradiation.

Chlorogenic acid biosynthesis: characterization of a light-induced microsomal 5-O-(4-coumaroyl)-D-quinate/shikimate 3'-hydroxylase from carrot (Daucus carota L.) cell suspension cultures.

Microsomal preparations from carrot (Daucus carota L.) cell suspension cultures catalyze the formation of trans-5-O-caffeoyl-D-quinate (chlorogenate) from trans-5-O-(4-coumaroyl)-D-quinate. trans-5-O-(4-Coumaroyl)shikimate is converted to about the same extent to trans-5-O-caffeoylshikimate. trans-4-O-(4-Coumaroyl)-D-quinate, trans-3-O-(4-coumaroyl)-D-quinate, trans-4-coumarate, and cis-5-O-(4-coumaroyl)-D-quinate do not act as substrates. The reaction is strictly dependent on molecular oxygen and on NADPH as reducing cofactor. NADH and ascorbic acid cannot substitute for NADPH. Cytochrome c, Tetcyclacis, and carbon monoxide inhibit the reaction suggesting a cytochrome P-450-dependent mixed-function monooxygenase. Competition experiments as well as induction and inhibition phenomena indicate that there is only one enzyme species which is responsibl for the hydroxylation of the 5-O-(4-coumaric) esters of both D-quinate and shikimate. The activity of this enzyme is greatly increased by in vivo irradiation of the cells with blue/uv light. We conclude that the biosynthesis of the predominant caffeic acid conjugates in carrot cells occurs via the corresponding 4-coumaric acid esters. Thus, in this system, 5-O-(4-coumaroyl)-D-quinate can be seen as the final intermediate in the chlorogenic acid pathway.

Phytochrome-induced flavonoid biosynthesis in mustard (Sinapis alba L.) cotyledons. Enzymic control and differential regulation of anthocyanin and quercetin formation.

Phytochrome-induced increases in enzyme activities for phenylalanine ammonia-lyase (EC 4.3.1.5) and chalcone isomerase (EC 5.5.1.6), and in amounts of the related end products, anthocyanin and the flavonol, quercetin, were measured in cotyledons of mustard (Sinapis alba L.). There was no correlation between the activities of these enzymes and the rate of anthocyanin accumulation; however, some correlation was found with the quercetin accumulation rate. Since anthocyanin and flavonol accumulation is spatially separated in mustard (flavonols in the upper epidermis, anthocyanin in the lower epidermis), it was possible to measure anthocyanin-associated phenylalanine ammonia-lyase independently. This activity correlated well with the accumulation rate for anthocyanin during the first few hours after induction. The phytochrome effect on anthocyanin formation differed from that on quercetin formation: anthocyanin was strongly induced by continuous far-red light and by both continuous red light and red light pulses, whereas quercetin was only effectively induced by continuous far-red light.

Isoflavonoid Formation as an Indicator of UV Stress in Bean (Phaseolus vulgaris L.) Leaves : The Significance of Photorepair in Assessing Potential Damage by Increased Solar UV-B Radiation.

Induction of the isoflavonoid pigment, coumestrol (3,9-dihydroxy-6H-benzofuro-[3,2-c][1] benzopyran-6-one), in primary leaves of beans (Phaseolus vulgaris L. var Saxa) by ultraviolet (UV) radiation was used as a quantifiable marker for UV damage to a plant system. Coumestrol was induced only by wavelengths below 300 nanometers and its formation could be reversed by treatment with white, but not red light after the UV irradiation period. Formation of coumestrol by UV could also be prevented over a period of 14 hours by simultaneous irradiation with blue light provided that the blue fluence rate was high enough. The results suggest that coumestrol formation is mediated via UV-induced pyrimidine dimer formation in the plant DNA and the photorepair properties of blue light are discussed with respect to possible increases in solar UV due to stratospheric ozone depletion.

UV-B Inhibition of Phytochrome-Mediated Anthocyanin Formation in Sinapis alba L. Cotyledons : Action Spectrum and the Role of Photoreactivation.

An action spectrum was measured for ultraviolet (UV) radiation-induced damage to (inhibition of) phytochrome-induced anthocyanin formation in cotyledons of 40-hour-old Sinapis alba L. seedlings. The action spectrum showed maximum effectiveness in the 260 to 280 nanometer waveband with little effect above 295 nanometers. The damaging effect of UV could be photorepaired by subsequent exposure to sunlight or to long wavelength (360 nanometers) UV radiation. Because this form of damage is subject to photorepair (photoreactivation), it is probably due to the formation of pyrimidine dimers, and the results suggest that it would not be ecologically relevant even if there was an increase in solar UV due to a decrease in stratospheric ozone levels of about 30%. If a dark period of more than 1 hour is interspersed between the phytochrome induction and the UV irradiation, the inhibition of the phytochrome induction gradually decreases with increasing dark period.

Somatic embryogenesis of tissue cultures of Papaver somniferum and Papaver orientale and its relationship to alkaloid and lipid metabolism.

Transfer from complete to 2,4-D free Gamborg's B5-medium efficiently induced somatic embryogenesis in Papaver tissue cultures (P. somniferum and P. orientale). Embryogenesis was preceded by a strong temporary accumulation of triacylglycerols. In both tissue cultures large amounts of sanguinarine type alkaloids were present, which disappeared during regeneration in the P. orientale cultures but persisted in the P. somniferum cultures. In the P. somniferum cultures protopine and morphine type alkaloids (morphine, codeine, thebaine) appeared about 45 days after exchanging the medium. Thebaine was the main alkaloid in the P. somniferum embryoids accumulating up to 0.2 % of dry weight.

Induction of phenylpropanoid compounds by UV-B irradiation in roots of seedlings and cell cultures from dill (Anethum graveolens L.).

In both cell cultures and seedling roots from dill (Anethum graveolens L.) UV irradiation selectively induced a quercetin arabinoside and two other phenylpropanoid compounds with caffeic acid as the aglycone. Only wavelengths below 360 nm were effective in this induction. Maximal effectiveness was observed below 320 nm.

Involvement of phytochrome and a blue light photoreceptor in UV-B induced flavonoid synthesis in parsley (Petroselinum hortense Hoffm.) cell suspension cultures.

Flavonoid synthesis in cell suspension cultures of parsley (Petroselinum hortense Hoffm.) occurs only after irradiation with ultraviolet light (UV), mainly from the UV-B (280-320 nm) spectral range. However, it is also controlled by phytochrome. A Pfr/Ptot ratio of approximately 20% is sufficient for a maximum phytochrome response as induced by pulse irradiation. Continuous red and far red light, as well as blue light, given after UV, are more effective than pulse irradiations. The response to blue light is considerably greater than that to red and far red light. Continuous red and blue light treatments can be substituted for by multiple pulses and can thus probably be ascribed to a multible induction effect. Continuous irradiations with red, far red and blue light also increase the UV-induced flavonoid synthesis if given before UV. The data indicate that besides phytochrome a separate blue light photoreceptor is involved in the regulation of the UV-induced flavonoid synthesis. This blue light receptor seems to require the presence of Pfr in order to be fully effective.

Coordinated induction and subsequent activity changes of two groups of metabolically interrelated enzymes. Light-induced synthesis of flavonoid glycosides in cell suspension cultures of Petroselinum hortense.

The enzymes of the flavonoid glycoside pathway were specifically induced upon irradiation of a 10-day-old, dark-grown cell suspension culture of Petroselinum hortense Hoffm. with ultraviolet light. The curves for the activity changes of a first sequence of three enzymes (group I) revealed only small, but significant, differences. Sharp peaks in these enzyme activities were observed at about 17, 22, and 23 h after the onset of the irradiation. The apparent half-lives during the subsequent periods of decline ranged, in the same order, from about 10 to 15 and 17 h. No significant differences were found for the lag periods preceding the increases in the three enzyme activities. The possibility is discussed that the slight differences in the patterns of the light-induced activity changes are mainly due to different rates of degradation of the enzymes, suggesting an otherwise largely interpendent regulation. The patterns of the activity changes of four enzymes of the second sequence (group II) differed greatly from those observed for group I, but were again similar to one another. Thus, the two groups of enzymes appear to be regulated differently, despite their concomitant induction. A sigmoidal curve for the accumulation of the flavonoid glycosides was obtained upon the induction of the enzymes. This curve corresponded closely to that derived by integration of the curve for the activity changes of the first enzyme of group I, phenylalanine ammonia-lyase. It is concluded that this enzyme might be rate-limiting for the entire pathway.

[Effect of radiation changes in the spectrum UV on plant organisms]. / Auswirkungen eines im UV-Spektralbereich veränderten Strahlungsangebotes auf pflanzliche Organismen

The synthesis of UV absorbing pigments (flavonoids), induced by UV (lambdamax less than 300 nm) with linear dose dependency, which we have recently observed in seedlings of the Umbelliferae, is described. This may provide a protective mechanism against an excess of solar UV radiation. The physiological importance of UV for the plant is discussed from the point of view of radiation damage and the plant's resistance to it.

Phytochrome-mediated de Novo Synthesis of Phenylalanine Ammonia-Lyase in Cell Suspension Cultures of Parsley.

After a preirradiation with ultraviolet light, phenylalanine ammonia-lyase activity in cell suspension cultures of parsley (Petroselinum hortense Hoff.) is controlled by phytochrome (red/far red photoreversibility). Isopycnic CsCl density gradient centrifugation, after labeling with (15)N (90 atom%) under inductive and noninductive conditions, was used to investigate the mode of action of phytochrome in this response. After a 5hour labeling period, a buoyant density shift of 0.009 kg.l(-1) (0.7%) without band-broadening (indicating close to maximal labeling of the enzyme), was observed in irradiated cells. In dark-grown controls, the density shift was 0.004 kg.l(-1) (0.3%), accompanied by significant band-broadening, indicating turnover of about half of the enzyme pool during 5 hours. These results are taken as evidence that phytochrome controls de novo synthesis of this enzyme over a background of basal turnover.

[Phytochrome control of enzymes involved in flavonoid synthesis in cell suspension cultures of parsley (Petroselinum hortense Hoffm.)]. / Durch Phytochrom kontrollierte Enzyme der Flavonoidsynthese in Zellsuspensionskulturen von Petersilie (Petroselinum hortense Hoffm.).

Enzymes involved in flavonoid synthesis in parsley (Petroselinum nortense Hoffm.) cell suspension cultures are induced by light. It has been suggested that the regulation of the enzymes of phenylpropanoid metabolism (group 1) is independent of that of the enzymes of flavonoid synthesis proper (group 2) [Hahl-brock, K., Ebel, J., Ortmann, R., Sutter, A., Wellmann, E., Grisebach, H.: Biochim. biophys. Acta (Amst.) 244, 7-15 (1971)]. Phytochrome was demonstrated to be involved in the light effect controlling flavonoid synthesis. Phytochrome is only effective after a preceding irradiation with ultraviolet light (λmax<300 nm) [Wellmann, E.: Planta (Berl.) 101, 283-286 (1971)]. - In order to determine whether phytochrome affects phenylalanine ammonia-lyase (PAL; EC 4.3.1.5), a group 1 enzyme, or exerts a general effect of all enzymes of the flavonoid pathway. PAL and two enzymes from group 2, chalcone-flavanone isomerase and UDP-apiose synthetase, were investigated. Under appropriate conditions of irradiation (low UV-dose with subsequent red/far-red pulses) both group 2 enzymes were shown to be controlled by phytochrome to the same extent as PAL. The UV-induced increase in activity of all three enzymes is reduced to about 70% by an irradiation for 10 min with far-red light. This far-red effect is fully reversible by a subsequent irradiation with 10 mith red light. There is no evidence for a rate limiting enzyme (or group of enzymes) involved in flavonoid formation with respect to phytochrome control.