tmRNA abundance in Streptomyces aureofaciens, S. griseus and S. collinus under stress-inducing conditions.

tmRNA and protein SmpB are the main components required for rescue of stalled ribosomes incapable of properly elongating or terminating the polypeptide chain. We examined the tmRNA level and protein synthesis in Streptomyces aureofaciens, S. griseus and S. collinus synthesizing tetracycline, streptomycin and kirromycin, respectively, during various stress conditions. Downshift in temperature caused a decrease in protein synthesis but the level of tmRNA increased. Shift up in temperature induced decay of tmRNA in all strains and in S. collinus led to stimulation and in S. aureofaciens and S. griseus to inhibition of protein synthesis. At high NaCl concentrations protein synthesis was inhibited and tmRNA decayed. Shift in pH from 7.0 to 5.0 had no pronounced effect on the tmRNA level while upshift to pH 9.0 in S. collinus and S. aureofaciens caused inhibition of protein synthesis and decay of tmRNA in S. collinus. In contrast, protein synthesis and tmRNA level increased in S. griseus at the alkaline pH. Our data show that tmRNA abundance is important for survival of streptomycetes under certain unfavorable conditions.

Effect of protein kinase inhibitors on protein phosphorylation and germination of aerial spores from Streptomyces coelicolor.

In vitro phosphorylation reaction using extracts prepared from cells in the exponential phase of growth and aerial spores of Streptomyces coelicolor displayed the presence of multiply phosphorylated proteins. Effect of protein kinase inhibitors (PKIs) (geldanamycin, wortmannin, apigenin, genistein, roscovitine, methyl 2,5-dihydroxycinnamate, rapamycin, staurosporine) was determined on protein phosphorylation and on germination of spores. The in vitro experiments showed differences in phosphoprotein pattern due to the presence of PKIs. Cultivation of aerial spores with PKIs led to a significant delay in germ tube emergence and filament formation. However, none of the tested PKIs completely blocked the germination process. These results indicate that protein kinases of spores form complex networks sharing common modulating site that plays an important role in proper timing of early developmental events.

Activity of translation system and abundance of tmRNA during development of Streptomyces aureofaciens producing tetracycline.

Transition from exponential phase of growth to stationary phase in Streptomyces aureofaciens is characterized by a decrease in the rate of translation and induction of tetracycline (Ttc) biosynthesis. In exponential phase, no significant changes were found in the activity of ribosomes at binding of ternary complex Phe-tRNA.EF-Tu.GTP to the A-site on ribosomes. Overexpression of Ttc in stationary phase is accompanied by a decrease in the binding of the ternary complex Phe-tRNA.EF-Tu.GTP to the A-site of ribosome and a formation of an aggregate with Ttc by part of the ribosomes. Antibiotics that cause ribosome to stall or pause could increase the requirement for tmRNA in the process called trans-translation. We found differences in the level of tmRNA during the development of S. aureofaciens. Subinhibitory concentrations of Ttc, streptomycin and chloramphenicol induced an increase in the tmRNA level in cells from the exponential phase of growth. In vitro trans-translation system of S. aureofaciens was sensitive to Ttc at a concentration of > 15 micromol/L; the trans-translation system can thus be considered to contribute to resistance against Ttc produced only at sublethal concentrations. These experiments suggest that the main role of the rising tmRNA level at the beginning of the Ttc production is connected with ribosome rescue.

Evidence for phosphoprotein phosphatase in Streptomyces granaticolor.

The existence of phosphoprotein phosphatase (PPP) in aerial mycelium of S. granaticolor was demonstrated. Using inhibitors of serine and/or threonine PPP and specifically labeled substrate it was found that the PPP is of the serine and/or threonine type.

[Familial form of Fahr syndrome (report of two cases)]. / Rodzinna postac zespolu Fahra (opis dwóch przypadków).

Two cases of familial form (in brothers) of extensive, symmetric, idiopathic calcifications of the basal ganglia and cerebellum (Fahr syndrome) are described. In discussion of factors predisposing to appearance of such idiopathic calcifications, particular attention was given to meningoencephalitis suffered in childhood and coexistence of a tumour of the sella of prolactinoma type, in case 1. Attention was also called to progressive, copious clinical and radiological symptology of the discussed cases. It was impossible to suggest a probable type of inheritance (parents of the patients were dead).

[Diagnostic problems in vertebral body hemangioma]. / Trudnosci diagnostyczne w rozpoznaniu naczyniaka trzonu kregu.

Vertebral haemangioma is a slowly growing benign tumour arising from blood vessels. Haemangioma of the vertebrae is usually asymptomatic. Neurological symptoms occur when haemangioma causes compression of nerve roots or spinal cord. In this paper a case of a 59 year-old woman with, vertebral body L2 haemangioma is reported. The signs and symptoms, modern imaging techniques (CT, MRI), differential diagnosis and treatment were discussed.

[Cervical pain as the only complaint in a patient with metastatic advanced lung carcinoma (case report)]. / Ból pochodzenia szyjnego jedyna dolegliwoscia u chorego z zaawansowanym przerzutowo rakiem pluc (opis przypadku).

Description of a case of metastatic advanced squamous cell lung carcinoma without any symptoms of the original focus. The only complaint of the patient almost throughout the course of the disease was cervical pain. Despite fast clinical course of the disease considerable adaptation of spinal cord to compression by metastatic focus in the vertebral column, may occur. Also numerous metastatic in bones or large foci in suprarenal glands may remain silent for a longer time of the disease. Examinations carried out: bons scinticsanning, CT of the abdominal cavity and MRI of cervical spine allowed to suspect that process with great probability, what was confirmed by autopsy.

Selection of medical technology students in a hospital-based program.

This article describes a process for selection of medical technology students into a hospital-based program. The process uses a weighting method for selection criteria and numerical ranking of applicants by a point system. Tools developed by the selection committee are discussed: Pre-Interview Rating Form, Interview Rating Form, Interview Rating Form Score Sheet, and Interview Questions Sets. The structured selection interview is described in detail. The process might easily be adapted to other hospital-based allied health programs.

Changes in ribosome function induced by protein kinase associated with ribosomes of Streptomyces collinus producing kirromycin.

Protein kinase associated with ribosomes of streptomycetes phosphorylates 11 ribosomal proteins. Phosphorylation activity of protein kinase reaches its maximum at the end of exponential phase of growth. When (32)P-labeled cells from the end of exponential phase of growth were transferred to a fresh medium, after 2 h of cultivation ribosomal proteins lost more than 90% of (32)P and rate of polypeptide synthesis increases twice. Protein kinase cross-reacting with antibody raised against protein kinase C was partially purified from 1 M NH(4)Cl wash of ribosomes and used to phosphorylation of ribosomes. Phosphorylation of 50S subunits (L2, L3, L7, L16, L21, L23, and L27) had no effect on the integrity of subunits but affects association with 30 to 70S monosomes. In vitro system derived from ribosomal subunits was used to examine the activity of phosphorylated 50S at poly(U) translation. Replacement unphosphorylated 50S with 50S possessed of phosphorylated r-proteins leads to the reduction of polypeptide synthesis of about 52%. The binding of N-Ac[(14)C]Phe-tRNA to A-site of phosphorylated ribosomes is not affected but the rate of peptidyl transferase is more than twice lower than that in unphosphorylated ribosomes. These results provide evidence that phosphorylation of ribosomal proteins is involved in mechanisms regulating the translational system of Streptomyces collinus.