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E Szewczyk

Publications and source records attributed to E Szewczyk.

16 recordsLinked to original sources
PubMed2001

A single gene produces mitochondrial, cytoplasmic, and peroxisomal NADP-dependent isocitrate dehydrogenase in Aspergillus nidulans.

NADP-dependent isocitrate dehydrogenase enzymes catalyze the decarboxylation of isocitrate to 2-oxoglutarate accompanied by the production of NADPH. In mammals two different genes encode mitochondrial and cytoplasmic/peroxisomal located enzymes, whereas in Saccharomyces cerevisiae three separate genes specify compartment specific enzymes. We have identified a single gene, idpA, in the filamentous fungus Aspergillus nidulans that specifies a protein with a high degree of identity to mammalian and S. cerevisiae enzymes. Northern blot analysis and reverse transcription-polymerase chain reaction revealed the presence of two idpA transcripts and two transcription start points were identified by sequencing cDNA clones and by 5'-rapid amplification of cDNA ends. The shorter transcript was found to be inducible by acetate and by fatty acids while the longer transcript was present in higher amounts during growth in glucose containing media. The longer transcript is predicted to encode a polypeptide containing an N-terminal mitochondrial targeting sequence as well as a C-terminal tripeptide (ARL) as a potential peroxisomal targeting signal. The shorter transcript is predicted to encode a polypeptide lacking the mitochondrial targeting signal but retaining the C-terminal sequence. Immunoblotting using antibody raised against S. cerevisiae Idp1p detected two polypeptides consistent with these predictions. The functions of the predicted targeting sequences were confirmed by microscopic analysis of transformants containing fluorescent protein fusion constructs. Using anti-Idp1p antibodies, protein localization to mitochondria and peroxisomes was observed during growth on glucose whereas cytoplasmic and peroxisomal localization was found upon acetate or fatty acid induction. Therefore, we have established that by the use of two transcription start points a single gene is sufficient to specify localization of NADP-dependent isocitrate dehydrogenase to three different cellular compartments in A. nidulans.

Amino Acid Sequence↗
PubMed2000

[Hypophosphatemic rickets].

Familiar hypophosphatemic rickets (X-linked hypophosphataemia) occurs very rarely, nevertheless it makes a significant medical problem because of the fact that misdiagnosed or late diagnosed leads to physical development retardation and to severe deformities of extremities. In the case of severe deformities the surgical treatment is needed. We present the case of the 5 year old girl with X-linked hypophosphataemia, who was late diagnosed, in spite of appearance of typical clinical symptoms (short stature and deformities of extremities) and typical laboratory findings (severe hypophosphataemia, serum calcium levels at the lower normal range). This girl had been "observed" (by a family doctor) for 3 years because of "varus deformity of legs". Despite considerably abnormal developmental parameters: height and weight << 3rd percentile (height >-3 s.d. for age), length of lower limbs >-3 s.d. for age and abnormalities in X-ray images of lower limbs (at the age of 3 5/12 presence of diaphysial deformations and abnormal metaphyses with zones of inadequate mineralization) the girl had not been diagnosed. After the admission to The Department of Pediatrics, Endocrinology and Disease of Adolescents: TRP 69.1%, PO4- 0.7-0.78 mmol/l, Ca 2.24-2.25 mmol/l, Mg 0.78 mmol/l, normal serum level of 25(OH)D (15.4 ng/ml [n. 11-54]), reduced serum level of 1 alpha 25(OH)2D (5.2 pg/ml [n. 15-70]), PTH 56 pg/ml [n. 10-70], ALP 401 U/l, ACP 9.5 U/l. 24-hour urine: PO4- 0.36-0.60 mmol/kg b.w., Ca 0.021 mmol/kg b.w. Probably, the girl will need surgical treatment because of severe bone deformities.

Child, Preschool↗
PubMed1994

Occurrence, purification and properties of the staphylococcal beta-hydroxybutyrate dehydrogenase.

beta-Hydroxybutyrate dehydrogenase (EC 1.1.1.30.)-an enzyme involved in degradation of polymer store material-was found in staphylococci. The enzyme was isolated from Staphylococcus xylosus NCTC D100694 cells, purified and characterized. The native enzyme is a tetramer and consists of equal subunits. Its relative molecular mass is M(r) = 140 kDa and pI = 4.7. The enzyme activity is stimulated by Mg+2 and Ca+2 ions. Staphylococcal beta-hydroxybutyrate dehydrogenase is relatively stable and active in a wide temperature range. The optimum pH for oxidation is 8.6 and for reduction 6.7. The enzyme is highly specific for D(-)stereoisomer of beta-hydroxybutyrate. Km values for beta-hydroxybutyrate and acetoacetate are 39.1 microM and 5.47 microM, respectively.

Acetoacetates↗
PubMed1993

[Etiology of bacterial endocarditis in materials from Cardiology and Cardiac Surgery Clinics of the Lodz Academy].

In the years 1986-1991, 72 cases of bacterial endocarditis (BE) were investigated. The bacteria were isolated from blood in 24 cases, from native and artificial valves obtained during surgery in 24 cases, and from both blood and valves in 6 cases. Following microorganisms were isolated: S. epidermidis, S. xylosus, S. hominis, S. aureus, Micrococcus sp., S. mitis, S. sanguis, S. faecalis, M. lacunata, E. adecarboxylata, P. maltophila, Corynebacterium sp., A. calcoaceticus var. lwoffii, and Aspergillus sp. Gram-positive bacteria were prevailing among isolated strains. Staphylococci were present in 55.7% (29 cases) and among them coagulase-negative staphylococci occurred in 89.7% (26 cases). Streptococci were isolated from 9 patients (17.3%) and Gram-negative rods from 5 patients (9.65%). Coryneform bacteria were detected in 7 cases (13.5%). There was no relation between type of removed valve and colonizing it bacteria. From native and artificial valves coagulase-negative staphylococci were isolated, respectively, in 48.3% and 52.2%. Susceptibility of isolated bacteria to 27 antibiotics was determined. Multiple resistant strains were present most frequently among staphylococci.

Actinomycetales↗
PubMed1993

[Bacterial flora of the hospital environment: identification, susceptibility to disinfecting agents, antibiotics and chemotherapeutics].

The studies were performed at the Intensive Care Unit of the Institute of Pediatrics. There were aimed at determination of cleanliness of boxes together with ante-rooms. At the same time bacterial flora of hospitalized children was investigated. The bacteria were isolated and identified by classical methods and by the API system. Among the identified strains, 60% constituted Gram-positive cocci with dominant participation of coagulase-negative staphylococci. Gram-negative rods (25% of total bacterial number) were represented mainly by Pseudomonas and Acinetobacter. Determination of susceptibility of tested strains toward 24 antibiotics and chemotherapeutics demonstrated wide occurrence of multiple antibiotic-resistance, particularly among enterococci and Gram-negative rods. Tests for susceptibility to disinfectants revealed presence of strains sensitive to chloramine in concentrations a dozen times higher when compared with standard strains. These strains occurred in the ward after systematic use of this disinfectant for many years. After replacement of chloramine by sterinol and chlorhexidine, these bacteria were not detectable after one year.

Acinetobacter↗
PubMed1992

A proposed mechanism of action of a growth hormone-specific monoclonal antibody in the enhancement of hormonal activity.

The potentiation of the biological activity of recombinant porcine growth hormone (pGH) by immunologic manipulation was investigated. An anti-pGH monoclonal antibody, designated PS-7.6, was generated and its effect on pGH was evaluated in hypophysectomized (hypox) rats. As expected, administration with pGH for 5 consecutive days promoted these animals to grow. The effect was further augmented when pGH was given together with PS-7.6 antibody and the enhancing ability of the antibody lasted beyond the treatment period. The growth profile of rats receiving antibody alone did not differ from that of untreated controls, indicating that PS-7.6 antibody by itself was not a growth stimulant. The possible mechanism of action of the antibody was investigated by analyzing blood and tissue samples of animals following injection with 125I-labeled pGH either in its free form or complexed with PS-7.6 antibody. As compared to the pGH levels in animals receiving free pGH, approximately a half pGH was released into circulation from the injection sites when it was given in a complex form. Furthermore, 2-4-fold increases in pGH deposition were also found in various tissues of animals treated with pGH-antibody complexes over that of respective tissues of animals receiving free pGH. Therefore, the present findings suggest that PS-7.6 antibody is capable of augmenting the somatogenesis of pGH and the effect is, at least in part, explainable by its ability in altering the pharmacokinetics and biodistribution of pGH in animals.

Animals↗
PubMed1990

Potentiation of the growth-promoting activity of porcine growth hormone (pGH) with an antibody generated in rabbits to the peptide sequence pGH110-118.

An effort was made to identify the antigenic epitope(s) of porcine GH (pGH) capable of inducing antibodies which would enhance the growth-promoting activity of the hormone. Several peptide sequences of the pGH molecule were synthesized and the antibodies to these peptides were generated in rabbits. The majority of these antibodies were found to be immunoreactive with both intact pGH and their respective peptide antigens. The biological activity of the antibodies was tested in growth-retarded hypophysectomized rats. Daily injections with pGH alone significantly increased their growth rate and treatment with a combination of pGH and antibody specific to the peptide sequence 110-118 further heightened the somatogenic effect. Administration of this antibody alone did not enhance the growth rate of hypophysectomized rats, neither did antibodies raised to intact pGH or the other peptide sequences. The present findings suggest that antibody with a particular pGH epitope specificity is able to increase the somatogenic activity of pGH and that the peptide corresponding to pGH amino acids 110-118 may prove useful in the development of growth promoting vaccines.

Amino Acid Sequence↗
PubMed1990

[Attempt at early detection of coronary insufficiency in patients with diabetes mellitus].

The upper extremity cooling test has been used for early detection of coronary insufficiency in 149 patients with diabetes mellitus and hypertension aged 40 to 60 years and electrocardiograms were evaluated prior and after the test according to the Minnesota Code. Additionally, in 49 subjects of above group the positive effort test has been performed revealing positive result in 22%, 4% exhibited the positive cooling test. In the group of 100 persons with arterial hypertension in whom the effort test has not been performed the positive cooling test has been noted in 6%. In the control group of 50 patients with arterial hypertension without diabetes, as well as in 50 healthy subjects the electrocardiographic alterations after the cooling test have not been observed and in 22% the effort test was positive. In the all groups studied after the cooling test the significant increase of systolic and diastolic pressure, the acceleration of the heart rate and the increase of double product (systolic pressure + heart action) has been noted. It has been concluded that the cooling test presents simple and useful but not sensible method of early detection of coronary insufficiency in patients with diabetes mellitus or arterial hypertension in whom there are contraindications for standard effort test.

Adult↗
PubMed1989

Poly-beta-hydroxybutyric acid in staphylococci.

Poly-beta-hydroxybutyric acid (PHB) was extracted from various species of staphylococci isolated from different sources. IR and UV spectrophotometry and NMR analysis revealed that the compound consisted only of the beta-hydroxybutyrate. The PHB level in the richest strain among investigated staphylococci is about 64-fold less than in bacilli. The intrinsic viscosity number of this polymer is more than twice greater in the case of the staphylococcal product than that of bacilli.

Hydroxybutyrates↗
PubMed1978

Coagulase in starved Staphylococcus aureus.

The resting cells of S. aureus strain Smith (diffuse) lost marked amount of free amino acids and proteins during their starvation. The starved cells contained less coagulase and that enzyme was released into the medium during starvation. After transfer into nutrient medium, those cells produced less coagulase than the non-starved ones. The restoration of amino acid pool resulted in coagulase production on initial level.

Amino Acids↗
PubMedDate not supplied

Computerized color-vision test based upon postreceptoral channel sensitivities.

An automated, computerized color-vision test was designed to diagnose congenital red-green color-vision defects. The observer viewed a yellow appearing CRT screen. The principle was to measure increment thresholds for three different chromaticities, the background yellow, a red, and a green chromaticity. Spatial and temporal parameters were chosen to favor parvocellular pathway mediation of thresholds. Thresholds for the three test stimuli were estimated by four-alternative forced-choice (4AFC), randomly interleaved staircases. Four 1.5-deg, 4.2 cd/m2 square pedestals were arranged as a 2 x 2 matrix around the center of the display with 15-minute separations. A trial incremented all four squares by 1.0 cd/m2 for 133 ms. One randomly chosen square included an extra increment of a test chromaticity. The observer identified the different appearing square using the cursor. Administration time was approximately 5 minutes. Normal trichromats showed clear Sloan notch as defined by log (deltaY/deltaR), whereas red-green color defectives generally showed little or no Sloan notch, indicating that their thresholds were mediated by their luminance system, not by the chromatic system. Data from 107 normal trichromats showed a mean Sloan notch of 0.654 (SD = 0.123). Among 16 color-vision defectives tested (2 protanopes, 1 protanomal, 6 deuteranopes, & 7 deuteranomals), the Sloan notch was between -0.062 and 0.353 for deutans and was < -0.10 for protans. A sufficient number of color-defective observers have not yet been tested to determine whether the test can reliably discriminate between protans and deutans. Nevertheless, the current data show that the test can work as a quick diagnostic procedure (functional trichromatism or dichromatism) of red-green color-vision defect.

Automation↗