[Lymphoma of the ocular adnexa]. / Lymphome der okulären Adnexe.

BACKGROUND: Lymphomas of the ocular adnexa are heterogeneous and demonstrate a wide range of clinical, histological, immunohistochemical and molecular genetic characteristics. AIM: The aim of this article is to give an overview of the interdisciplinary diagnostics and individually adapted lymphoma subtype-based therapy. DIAGNOSTICS: Depending on the lymphoma localisation, i.e. whether in the eyelid, the conjunctiva or in the orbit, a photograph or a radiological scan is required to record the tumor extent. Visual function is more likely to be impacted when the lymphoma arises in the posterior orbit, close to the optic nerve and imaging diagnostics are therefore necessary. Histological investigations are essential for confirming the lymphoma diagnosis and give information about the particular subtype, which in turn will determine subsequent patient management, Clinical staging investigations for determining the systemic extent of the lymphoma manifestation (e.g. imaging, blood analyses as well as bone marrow biopsy) are mandatory. THERAPY: External beam radiation, local and systemic chemotherapy or in some cases antibiotics are treatment options after surgical excision in isolated ocular adnexal lymphoma. The TNM classification of the American Joint Committee on Cancer or the Ann Arbor staging system, as well as the guidelines of the German Society of Hematology and Medical Oncology are all tools to aid the choice of the appropriate individually adapted therapy for systemic disease, which includes psycho-oncological care.

Expression and activity of cell-wall-degrading enzymes in the latex of opium poppy, Papaver somniferum L.

The alkaloid-rich latex of the opium poppy, Papaver somniferum L., is valued as a source of pharmaceuticals including thebaine, codeine, and morphine, but is also harvested for heroin production. The poppy laticifer system develops through the gradual disappearance of the common walls between differentiating laticifer elements throughout the plant. Gene homologues for cell-wall-degrading enzymes were found during random sequencing of an opium poppy latex cDNA library. RNA gel blot analysis of cellulase, polygalacturonase beta-subunit, 1,3-beta-glucanase, and xyloglucan endotransglycosylase homologues showed their expression was not limited to laticifers. In contrast, poppy gene homologues to pectin methylesterase (PME), pectin acetylesterase (PAE) and pectate lyase (PL) where all highly expressed and latex-specific. Enzyme assays confirmed the presence of PME, PAE, and PL activities in latex serum. The abundance of transcripts encoding pectin-degrading enzymes in latex suggests that these enzymes may play an important role in laticifer development.

Role of actin cortex in the subplasmalemmal transport of secretory granules in PC-12 cells.

In neuroendocrine PC-12 cells, evanescent-field fluorescence microscopy was used to track motions of green fluorescent protein (GFP)-labeled actin or GFP-labeled secretory granules in a thin layer of cytoplasm where cells adhered to glass. The layer contained abundant filamentous actin (F-actin) locally condensed into stress fibers. More than 90% of the granules imaged lay within the F-actin layer. One-third of the granules did not move detectably, while two-thirds moved randomly; the average diffusion coefficient was 23 x 10(-4) microm(2)/s. A small minority (<3%) moved rapidly and in a directed fashion over distances more than a micron. Staining of F-actin suggests that such movement occurred along actin bundles. The seemingly random movement of most other granules was not due to diffusion since it was diminished by the myosin inhibitor butanedione monoxime, and blocked by chelating intracellular Mg(2+) and replacing ATP with AMP-PNP. Mobility was blocked also when F-actin was stabilized with phalloidin, and was diminished when the actin cortex was degraded with latrunculin B. We conclude that the movement of granules requires metabolic energy, and that it is mediated as well as limited by the actin cortex. Opposing actions of the actin cortex on mobility may explain why its degradation has variable effects on secretion.

Does dexamethasone enhance the efficacy of alizapride in cis-platinum-induced delayed vomiting and nausea?

At the present time 5-HT3 antagonists in combination with corticosteroids represent the best prophylaxis and treatment of acute vomiting and nausea in highly emetogenic cancer chemotherapy. However, 24 h after chemotherapy 5-HT3 antagonists are no longer superior to benzamides for prevention of delayed symptoms. All recommendations for use of corticosteroids in delayed nausea and vomiting basically rely on one small study by Kris et al. [J Clin Oncol 1989;7:108-114]. Since the use of corticosteroids in cancer chemotherapy remains controversial, this single-blind, randomised, prospective trial was initiated to re-evaluate the benefits of corticosteroids during the days after chemotherapy. Thus patients treated for ovarian cancer received 5 mg tropisetron (Navoban) plus 20 mg dexamethasone for the prevention of acute vomiting and nausea in cis-platinum-containing chemotherapy (50 mg). Twenty-four hours after the beginning of chemotherapy 49 patients were randomised to receive 3 x 100 mg alizapride (Vergentan) plus a placebo medication (group A) and 47 patients to receive 3 x 100 mg alizapride plus 3 x 4 mg dexamethasone (group B) for 3 days depending on the incidence of acute vomiting beginning on day 2. The well-being of both groups was compared using objective and subjective parameters (Rotterdam Symptom Checklist). Major control of acute vomiting was achieved in 87.5% of the cases. The study was stopped after this interim analysis of 96 patients revealed no advantage of corticosteroids during the days after chemotherapy. Significant differences between both groups were detected only on a few days (day 6: objective nausea in favour of group A, day 4: objective vomiting in favour of group B, day 6: objective vomiting in favour of group A, day 3: constipation in favour of group A, days 4 and 5: difficulty concentrating in favour of group A, day 3: dry mouth in favour of group B). In contrast to acute nausea and vomiting the addition of corticosteroids is not beneficial in the prevention of delayed nausea and vomiting. Until better strategies are available the best prophylaxis of delayed symptoms is the control of acute nausea and vomiting using 5-HT3 antagonists plus corticosteroids. The use of benzamides has to be considered efficacious in the prevention of delayed vomiting and nausea.

Ca2+-triggered peptide secretion in single cells imaged with green fluorescent protein and evanescent-wave microscopy.

Green fluorescent protein fused to human chromogranin B or neuropeptide Y was expressed in PC12 cells and caused bright, punctate fluorescence. The fluorescent points colocalized with the endogenous secretory granule marker dopamine beta-hydroxylase. Stimulation of live PC12 cells with elevated [K+], or of permeabilized PC12 cells with Ca2+, led to Ca2+-dependent loss of fluorescence from neurites. Ca2+ stimulated secretion of both fusion proteins equally well. In living cells, single fluorescent granules were imaged by evanescent-wave fluorescence microscopy. Granules were seen to migrate; to stop, as if trapped by plasmalemmal docking sites; and then to disappear abruptly, as if through exocytosis. Evidently, GFP fused to secreted peptides is a fluorescent marker for dense-core secretory granules and may be used for time-resolved microscopy of single granules.

Evidence for an in vivo modification of mitochondrial proteins by coenzyme A.

Following denaturation of mitochondrial proteins by sodium dodecyl sulfate, a [1-14C]pantothenic acid-derived radioactivity proved to be acid precipitable in the outer membrane, the intermembrane space, the inner membrane and in the matrix of rat liver mitochondria, where it had the highest specific radioactivity of 541 +/- 29 cpm/100 micrograms protein. This tightly and/or covalently bound protein radioactivity could be released by incubation in the presence of dithioerythreitol; it was identified as [14C]coenzyme A by its HPLC retention time, its absorption spectrum and its radioactivity. This acid-stable and thiol-labile coenzyme A-binding apparently refers to specific protein binding sites. With the purified, homogeneous mitochondrial matrix enzymes acetyl-CoA acetyltransferase (acetoacetyl-CoA thiolase) (EC 2.3.1.9, acetyl-CoA:acetyl-CoA C-acetyltransferase) and 3-oxoacyl-CoA thiolase (EC 2.3.1.16) coenzyme A was found exclusively, e.g., in the modified, partially-active forms A1 und A2 of acetyl-CoA acetyltransferase and not in the unmodified fully-active enzyme. Thus it is evident that this coenzyme A modification is transient. We suggest that coenzyme A-modification is a signal involved in the assembly or the degradation process of distinct mitochondrial matrix proteins.

[Escape of hydrogen peroxide and oxygen from the root canal]. / Untersuchungen zum Austritt von Wasserstoffperoxid und Sauerstoff aus dem Wurzelkanal.

In vitro investigations demonstrate that hydrogen peroxide, like the oxygen emitted from the root canal, escapes into the area around the root. The amount measurable was dependent on the concentration, the amount of time that the hydrogen peroxide was left in the root canal and the patency of the foramen apicale. The growth of the Staphylococcus aureus (SG 511) was restricted in the area around those roots whose root canal contained a 5% solution of hydrogen peroxide.

Influences of the chemical structure on the activity of new inhibitory compounds of the angiotensin-converting enzyme.

The ACE inhibitory activity of some perimidines, chinazolinones and amidinohydrazones is described. Relations were found between the chemical structure and the inhibitory activity on the ACE.

Evidence against co-storage of enkephalins with noradrenaline in bovine adrenal medullary granules.

Bovine adrenal chromaffin granules were purified and separated into adrenaline (A) and noradrenaline (NA) containing granule populations by a combination of differential and isopycnic gradient centrifugation. The distribution of [Leu5]enkephalin as measured by radioimmunoassay followed a pattern identical to adrenaline but not noradrenaline on centrifugation. This suggests that enkephalins are stored in the same type of granule where adrenaline is found or that enkephalins and adrenaline even coexist in one and the same granule. Enkephalins may therefore function as co-transmitters or co-hormones of adrenaline rather than noradrenaline in the adrenal medulla.

ATP synthesis and generation of electrochemical gradients of protons in the catecholamine storage organelle of the adrenal medulla.

The reaction rates of ATP formation from ADP and inorganic phosphate (Pi) by the catecholamine storage organelles isolated from bovine adrenal medulla accelerated 5--6 fold, when Pi was added at various times after addition of Mg-ADP, as compared to the rates observed when the reaction partners were added simultaneously. The increase of the rates of ATP-Pi exchange upon subsequent addition of Pi to Mg-ATP was less prominent. Mg-ADP induced a delta psi (60--70 mV, positive inside), almost equal that induced by Mg-ATP. In both cases delta psi was significantly higher in the absence of Pi than in its presence. At pH 7.4 of the medium the delta pH was 1.4 units indicating an internal pH of 6. It was stable during the reaction time in the presence of Mg-ATP, while in the presence of Mg-ADP the internal pH increased gradually by 0.2 units. Both the ATP forming reactions as well as the nucleotide induced delta psi were uncoupler-sensitive (CCCP). Though inhibiting ATP formation from ADP + Pi by 50%, 0.1 mM AP5A (an inhibitor of adenylate kinase) did neither affect delta psi nor delta pH, hence ruling out the possibility that delta microH. induced by Mg-ADP would be actually due to AtP formed from ADP. Membrane ghosts were not able of ATP synthesis (in the absence of valinomycin), the ATP-Pi exchange was only 10--20% of that of intact organelles, due to the low delta microH. in the absence of intravesicular soluble constituents. It is proposed that the energy for ATP synthesis is furnished by the high gradients of protonated soluble constituents in the intact organelles.

Phosphoryl group transfer by a fraction of the soluble proteins of catecholamine storage vesicles.

The terminal phosphate group of ATP was transferred to ADP by an enzyme present in the soluble core proteins of adrenal medulla catecholamine storage vesicles. It was purified 10-30-fold by DEAE Sephadex chromatography (Fraction I). The enzyme required divalent metal ions for activation; Mn2+ was almost as effective as Mg2+, but Ca2+ was only a weak activator. Activation by Mg2+ took place over a very narrow concentration range (0.5-3 mM). The specificity of the enzyme activity to nucleoside triphosphates was broad, to the nucleoside diphosphates narrow, favouring adenosine diphosphate. In dependence on the pH the activity increased from pH 4 to pH 7 and remained constantly high between pH 7 and 9. The Arrhenius plot was linear between 5 and 70 degrees C, with an activation energy of 11.1 kcal/mol. The phosphoryl group transfer reaction depended on the function of thiol groups; p-hydroxymercuribenzoate inhibited 50% of the enzyme activity; dithioerythritol reactivated it completely. Gel electrophoresis revealed that in Fraction I, a protein of molecular weight about 45,000, was enriched compared with the total proteins. The enzyme-enriched Fraction I differed significantly in its relative amino acid composition from that of the total soluble proteins; in general, the acidic amino acids were reduced and the more basic acids enhanced.

Distribution and metabolic fate of adenosine nucleotides in the membrane of storage vesicles from bovine adrenal medulla.

The reactions of adenosine 14C-and gamma 32P-labelled ATP with isolated membranes from catecholamine storage vesicles of the bovine adrenal medulla were studied. In presence of Mg2+ about twice as much of 32P-radioactivity combined with the membrane as 14C-adenosine compounds at 31 degrees C and also at 0 degrees C, while in the absence of Mg2+ the amounts of 14C and 32P incorporated were similar for both substances. Autoradiography of the SDS-polyacrylamide gel after electrophoresis of the 32P-ATP-treated membrane protein showed two distinct zones corresponding to protein bands. Sonication released twice as much 32P-ATP as 14C-ATP from the space within the membrane particles indicating that at least half of the ATP present in space did not contain its original terminal phosphate group. About 40--45% of the 32P-radioactivity was incorporated in the membrane lipids, whereas only small amounts of 14C-radioactivity were extracted with lipids. About 1/3 of the incorporated 14C-radioactivity was not extractable with acids. The same amount remained in the 32P-ATP treated preparation acid-stably bound after extraction of the lipids and hus must be firmly bound ATP. When the reaction of the membrane preparation with labelled ATP was performed at 0 degrees C the fractions of the acid-stably bound 32P- and 14C-radioactivity increased. About 1 nmole/mg of protein (10--15%) of the bound 32P-radioactivity was exchangeable against unlabelled ATP, while only a very small fraction (less than 0.5 nmol/mg protein) of the 14C-radioactivity was exchanged against unlabelled ATP. Preincubation of the membrane particles with ATP-Mg2+ at 0 degrees C induced 30% inhibition of the ATPase activity and abolition of the net uptake of catecholamines. Different Km values obtained from initial velocity studies of ATPase activity and the overall-incorporation of 32P-radioactivity indicated that a direct correlation between these processes did not exist. Different strong inhibitory effects exerted by ADP on the ATPase activity and net uptake of catecholamine at the one hand and the overall 32P-and 14C-incorporation at the other hand supported that view. It is concluded that small fractions of the observed 32P-and 14C-incorporation can be involved in the ATP hydrolyzing reaction.

Partial characterization of a phosphoryl group transferring enzyme in the membrane of catecholamine storage vesicles.

Phosphoryl group transfer from ATP to ADP occurred in the isolated membrane of catecholamine storage vesicles. The reaction was accelerated by extraction of the membranes with 50% (v/v) acetone and by treatment with 1% (v/v) Triton X-100. The phosphoryl group transfer reaction was activated by Mg2+ and by Mn2+. The activation profile differed from that obtained for the ATPase activity. The Michaelis-Menten kinetics of the phosphoryl transfer reaction were not entirely linear. From the linear parts of the double reciprocal plots KmATP approximately equal to 1 mM and KmADP approximately equal to 0.4 mM was obtained. All lines of the double reciprocal plots intersected indicating a sequential reaction mechanism. The reaction exhibited a narrow specificity for nucleoside diphospate and a broader one for nucleoside triphosphate indicating that ADP was the true substrate. The transfer reaction was slightly inhibited by AMP, orthophosphate and P1, P5-di(adenosine-5')pentaphosphate. The thiol reagents, N-ethylmaleimide and para-chloromercuribenzoate (PCMB), affected the ATPase activity and the phosphoryl transfer activity differently: with the blockade of 2.4 essential thiol equivalents by N-ethylmaleimide the ATPase was inhibited 50% and net uptake of catecholamine ceased, while the phosphoryl transfer remained unimpaired. PCMB affected both, the ATPase activity and phosphoryl transfer reaction. Treatment of the membranes with dithioerythritol prevented the PCMB-induced inhibition of the phosphoryl transfer, but was ineffective in protecting the ATPase activity, indicating that different thiol groups must be involved in the both enzymatic activities.