The possible role of factor C in common scab disease development.

The Gram-positive soil-borne streptomycetes exhibit a complex life cycle that is controlled by extracellular regulatory molecules. One interesting autoregulator is the protein factor C, originally isolated from the culture fluid of S. albidoflavus 45H. Southern hybridizations and database searches revealed that although homologues of factor C are not present in most Streptomyces strains, an exception is the plant pathogenic S. scabies , which causes common scab disease on potato. In S. scabies and related strains pathogenicity involves a large pathogenicity island that carries thaxtomin biosynthetic genes, the nec1 necrogenic factor and other putative virulence genes. Extracellular enzymes, including extracellular esterases, that attack the surface of the tubers and disintegrate the external protective layer are also known to be involved in pathogenicity. In S. albidoflavus 45H, factor C coordinates the expression of many secreted hydrolases. To find out whether esterase is also regulated by factor C, we made a factor C null mutant of strain 45H. The mutant showed a bald phenotype and was impaired in pathogenicity and esterase activity. This is a first indication that extracellular regulatory factors may play a role in the development of potato scab.

N-Alkane uptake and utilisation by Streptomyces strains.

Streptomyces strains isolated from the Kuwait Burgan oil field were defined as S. griseoflavus, S. parvus, and S. plicatus utilised n-hexadecane, n-octadecane (purified fractions of mineral oil), kerosene, and crude oil as sole carbon and energy sources. The strains were incubated with n-alkanes and increase of the fatty acid content with chain length equivalent to the employed n-alkanes was observed. Signal transducing GTP-binding proteins (GBPs) play an important role in n-alkane uptake in streptomycetes. Specific activators of GBPs increased the uptake of hydrocarbons. Using the hydrophobic fluorescent dye diphenylhexatrien (DPH) as a probe, it was found that the microviscosity of the hydrophobic inner region of the cellular membrane is significantly lower in hydrocarbon utilisers than in non-utilisers. This difference probably reflects differences in the fatty acid composition of the strains. When cultures were grown in n-alkane containing media, electron microscopy revealed that the hydrocarbon utilisers showed less-electron dense areas as inclusions in the cytoplasm. Soil samples inoculated with Streptomyces strains eliminated hydrocarbons much faster than those not containing these strains, serving as control. When inorganic medium was supplied with n-hexadecane-1-14C as sole carbon and energy source, radioactive CO2 was detected. Since streptomycetes have not been used until now for oil elimination, though they are known as abundant soil bacteria tolerating extreme conditions, their possible use for bioremediation of hydrocarbon contaminated soils is discussed.

A possible role of the effect of methionine on the activity of aspartokinase in sporulation of a Streptomyces fradiae mutant.

In addition to methionine, aspartate may also induce sporulation in the Streptomyces fradiae St3110 mutant that requires methionine for sporulation but not for growth. Partially purified aspartokinase (EC 2.7.2.4.) of the mutant was tested for feed-back control by methionine, threonine, and lysine. Methionine or threonine alone did not have any significant effect but they had a concerted inhibitory effect together that was further increased by lysine. The threonine-lysine combination also caused inhibition of the enzyme activity, while lysine alone activated the enzyme. Methionine was also found to partially repress the aspartokinase activity to about one third of the control. The sporulating aerial mycelia induced by aspartate were lacking the characteristic sporulation pigmentation present in the wild type or after induction of spores by methionine. No significant difference in heat resistance between the two types of the spores was detected. The number of spores produced by aspartate was only about one fourth of that after induction by methionine. The data may indicate a role of aspartokinase control by methionine in restoring the normal sporulation, although in addition to this methionine may act by a different mechanism, as well.

The possible role of ADP ribosylation in physiological regulation of sporulation in Streptomyces griseus.

The role of ADP ribosylation of proteins in the physiological regulation of sporulation in Streptomyces griseus was studied. We report here that both the activity of NAD+: arginine ADP-ribosyltransferase (ADPRT) and the pattern of ADP-ribosylated proteins showed characteristic changes during the life cycle in S. griseus 2682. Analysis off ADP-ribosylated proteins revealed that in a nonsporulating mutant of the parental wild-type (wt) strain (Bld7 mutant), both the activity of ADPRT and the pattern of ADP-ribosylated proteins were different from those of the parental strain. Addition of 3-aminobenzamide (3AB), the most potent inhibitor of ADPRT, inhibited sporulation of S. griseus 2682 and the A-factor (AF)-induced sporulation of S. griseus Bld7, but in both cases the inhibitory effect of 3AB was strictly age-dependent. Using [alpha-32P]GTP, we have demonstrated the presence of GTP-binding proteins in purified cell membranes of S. griseus 2682 and S. griseus Bld7. The same GTP-binding proteins were observed in Bld7 and the wt. AF stimulated the basal GTPase activity of cell membranes of S. griseus 2682 in a concentration-dependent manner, suggesting that GTP-binding proteins might be involved in the AF-induced sporulation process.

Activity of "nonspecific pancreatic carboxylesterase" in rat serum in experimentally induced acute pancreatitis (preliminary results).

The aim of this study was to obtain more information on the serum level of "nonspecific pancreatic carboxylesterase" (PCE) in experimentally induced acute pancreatitis in rats. The effects of caerulein stimulation, hepatic duct ligation, bile-pancreatic duct ligation or the effect of retrograde injection of saline, 5% taurocholate and sunflower oil were investigated. The activity of PCE and amylase was measured in the serum, pancreatic tissue, pancreatic juice and ascitic fluid. The changes in PCE activity were greater (both in directions to increase or decrease) than that of amylase, produced by different experimental procedures. The results confirm the thesis that the serum activity of PCE is a more sensitive diagnostic method than that of amylase to detect the inflammatory process in the pancreas or the effect of obstruction of the pancreatic duct.

[Sonography of experimental hypovascularized kidney tumors]. / Sonographie von experimentellen hypovaskularisierten Nierentumoren.

The authors studied the sonographic features of Vx2-renal carcinomas in rabbits induced by the Vargha method. The series consisted of 81 rabbits with Vx2-renal carcinomas, 17 controls, five rabbits with retrorenal Vx2-carcinomas and 56 rabbits with gluteal Vx2-carcinomas. In 70.8% ultrasound showed changes on the tenth day and in 98.6% on the 14th day; usually these were of low echogenicity, in 32.4% there was mixed echogenicity and in a few a highly echogenic pattern was found. After 21 days the ultrasound pattern became increasingly of poor echogenicity. 41.3% showed of necrosis by 14 days and after 21 days 100% were necrotic. On the seventh day Vx2-renal carcinomas were mostly hyper-reflective.

Fifteen year follow-up of lung function in obstructive and non-obstructive pulmonary tuberculosis.

Pulmonary function (VC, FEV1, RV) was assessed in patients with pulmonary tuberculosis discharged in 1958/59 as cured or markedly improved. According to FEV1/VC% the patients were divided into 40 obstructive and 59 non-obstructive cases and the tests were repeated by the same method in 1974. The control included physical and X-ray examinations, a questionnaire and the assessment of airway resistance (Rt). In the non-obstructive group the change in VC in 15 years was only -27.7 ml/year, in the obstructive group, -54.3 ml/year. There was little difference between the two groups in the diminution of FEV1 (28.8 and 35.3 ml/year, respectively). The material was subdivided into surgically and drug treated groups and studied statistically. The only significant change of function in the surgically treated group was in RV, whereas in the other group nearly all of the functional changes were significant statistically.

[Results of radiation therapy of cancer of the lip (author's transl)]. / Ergebnisse der Strahlenbehandlung des Lippenkarzinoms.

The authors are presenting the 5-year survival rates of 170 patients treated for carcinoma of the lip at the radiological department of the Medical University in Debrecen. The results of radiation therapy, clarified and stage-correlated, are as follows: T1 100%, T2 90.2%, T3 67.9%. They call attention to the fact that in planning and carrying out the schedule of radiation treatment its effectiveness is stage-dependent. In radiation treatment applied in conformity with this, the basic laws of radiation therapy have to be observed. In the treatment of Stages T1 the optimal added-up radiation effectiveness lies at 2000 to 2500 reu with Chaoul tubes 1 and 2, for Stages T2 at 2300 to 2600 reu with Chaoul tubes 3 and 4, for Stages T3 at 2500 to 2600 reu with Chaoul tubes 3, 6 or 10 and additional telecobalt irradiation of the corresponding lymphatic chains.