Biomedical subjects

D Kowalski

Publications and source records attributed to D Kowalski.

At least 37 records · Page 2Linked to original sources

PubMed1994

Multi-centre comparison of ABBOTT MATRIX Aero to Pharmacia Standard RAST, Modified RAST and skin puncture tests.

ABBOTT MATRIX Aero is an enzyme immunoassay which measures specific IgE antibodies to 14 individually calibrated airborne allergens using a single serum specimen. In this study, ABBOTT MATRIX performance was evaluated in comparison to the results of skin puncture test and the Standard and Modified RAST procedures. The ABBOTT MATRIX demonstrated overall sensitivity of 89% vs. Standard RAST and Modified RAST, with specificity greater than 92% vs. both methods. ABBOTT MATRIX sensitivity vs. skin test (71%) exceeded that of the Standard and Modified RAST procedures (62% and 67% respectively). Positive results reported by ABBOTT MATRIX but not RAST were corroborated by skin test results for 3 of 5 allergens evaluated. All in vitro systems demonstrated specificity of approximately 90% vs. skin test. The ABBOTT MATRIX system provided results which compared favorably with the results of skin test and RAST, but required less hands-on time to obtain quantitative specific IgE measurements to multiple allergens.

Adolescent↗

PubMed1994

[Level of endothelin-1 and 2 in plasma of patients with chronic renal failure].

The aim of the study was to answer 3 questions: 1. does plasma endothelin level differ in patients with chronic renal failure from that of healthy subjects. 2. does plasma endothelin level differ in patients with chronic renal failure treated with haemodialysis from those treated without dialysis. 3. does plasma endothelin level change during haemodialysis. 63 patients with chronic renal failure (pnn, 23 treated without dialyses and 40 with dialyses) as well as 20 healthy subjects were studied. Plasma endothelin and creatinine were estimated under basal conditions and in the dialysed patients--immediately after dialysis. Plasma endothelin level was higher in patients with pnn than in normals, regardless to dialysotherapy. It rose after dialysis. Plasma creatinine fell after dialysis. Positive significant correlation was found between the levels of creatinine and endothelin in the whole group studied.

Adult↗

PubMed1994

[Changes in levels of glucose, insulin, c-peptide, glucagon and potassium in serum of patients with bronchial asthma during stimulation with b2-adrenergic fenoterol].

The study was carried out on 40 patients with bronchial asthma (20 with atopic and 20 with non-atopic) and 20 healthy subjects as controls. After fenoterol stimulation in asthmatic and control groups an increase of glucose level and decrease of potassium concentration were documented. Moreover, a slight increase of insulin, C-peptide and glucogene++ release was suggested.

Adolescent↗

PubMed1993

Ease of DNA unwinding is a conserved property of yeast replication origins.

Autonomously replicating sequence (ARS) elements function as plasmid replication origins. Our studies of the H4 ARS and ARS307 have established the requirement for a DNA unwinding element (DUE), a broad easily-unwound sequence 3' to the essential consensus that likely facilitates opening of the origin. In this report, we examine the intrinsic ease of unwinding a variety of ARS elements using (1) a single-strand-specific nuclease to probe for DNA unwinding in a negatively-supercoiled plasmid, and (2) a computer program that calculates DNA helical stability from the nucleotide sequence. ARS elements that are associated with replication origins on chromosome III are nuclease hypersensitive, and the helical stability minima correctly predict the location and hierarchy of the hypersensitive sites. All well-studied ARS elements in which the essential consensus sequence has been identified by mutational analysis contain a 100-bp region of low helical stability immediately 3' to the consensus, as do ARS elements created by mutation within the prokaryotic M13 vector. The level of helical stability is, in all cases, below that of ARS307 derivatives inactivated by mutations in the DUE. Our findings indicate that the ease of DNA unwinding at the broad region directly 3' to the ARS consensus is a conserved property of yeast replication origins.

Chromosomes, Fungal↗

PubMed1993

A DNA unwinding element and an ARS consensus comprise a replication origin within a yeast chromosome.

We have defined a replication origin, ORI305, within chromosome III of Saccharomyces cerevisiae by means of mutational analysis. cis-acting elements required for origin activity in the chromosome, as assayed by two-dimensional gel electrophoresis of replication intermediates, are the same as those required for the function of an autonomously replicating sequence, ARS305, in a plasmid. Essential elements include (i) an 11 bp sequence that is a near match to the ARS consensus and (ii) a broad sequence directly 3' to the consensus near match. Origin function is inactivated by point mutations in the essential near match sequence, suggesting that the sequence contributes to specifying the origin in the chromosome. Other consensus near matches with different sequences are present but are not required. The essential 3'-flanking sequence exhibits DNA helical instability and is sensitive to deletion mutations that stabilize the DNA helix. The wild-type 3'-flanking sequence can be functionally substituted by dissimilar sequences that also exhibit helical instability. The requirement for DNA helical instability indicates that the essential 3'-flanking sequence serves as a DNA unwinding element in the chromosome.

Amino Acid Sequence↗

PubMed1993

Easily unwound DNA sequences and hairpin structures in the Epstein-Barr virus origin of plasmid replication.

The Epstein-Barr virus (EBV) origin of plasmid replication (oriP) includes two known cis-acting components, the dyad symmetry region and the family of repeats. We used P1 nuclease, a single-strand-specific endonuclease, to probe EBV oriP for DNA sequences that are intrinsically easy to unwind on a negatively supercoiled plasmid. Selective nuclease hypersensitivity was detected in the family of repeats on an oriP-containing plasmid and in the dyad symmetry region on a plasmid that lacks the family of repeats, indicating that the DNA in both cis-acting components is intrinsically easy to unwind. The hierarchy of nuclease hypersensitivity indicates that the family of repeats is more easily unwound than the dyad symmetry region, consistent with the hierarchy of helical stability predicted by computer analysis of the DNA sequence. A specific subset of the family of repeats is nuclease hypersensitive, and the DNA structure deduced from nucleotide-level analysis of the P1 nuclease nicks is a cruciform near a single-stranded bubble. The dyad symmetry region unwinds to form a broad single-stranded bubble containing hairpins in the 65-bp dyad sequence. We propose that the intrinsic ease of unwinding the dyad symmetry region, the actual origin of DNA replication, is an important component in the mechanism of initiation.

Base Sequence↗

PubMed1993

cis-acting components in the replication origin from ribosomal DNA of Saccharomyces cerevisiae.

The ribosomal DNA (rDNA) repeats of Saccharomyces cerevisiae contain an autonomously replicating sequence (ARS) that colocalizes with a chromosomal origin of replication. We show that a minimal sequence necessary for full ARS function corresponds to a 107-bp rDNA fragment which contains three 10-of-11-bp matches to the ARS consensus sequence. Point mutations in only one of the 10-of-11-bp matches, GTTTAT GTTTT, inactivate the rDNA ARS, indicating that this consensus sequence is essential. A perfect match to a revised ARS consensus is present but not essential. Sequences up to 9 bp 5' from the essential consensus are dispensable. A broad DNA region directly 3' to the essential consensus is required and is easily unwound as indicated by: (i) hypersensitivity to nicking of an approximately 100-bp region by mung bean nuclease in a negatively supercoiled plasmid and (ii) helical instability determined by thermodynamic analysis of the nucleotide sequence. A correlation between DNA helical instability and replication efficiency of wild-type and mutated ribosomal ARS derivatives suggests that a broad region 3' to the essential ARS consensus functions as a DNA unwinding element. Certain point mutations that do not stabilize the DNA helix in the 3' region but reduce ARS efficiency reveal an element distinct from, but overlapping, the DNA unwinding element. The nucleotide sequence of the functionally important constituents in the ARS appears to be conserved among the rDNA repeats in the chromosome.

Base Sequence↗

PubMed1993

[Levels of endothelin and atrial natriuretic peptide (ANP) in plasma of patients with chronic renal failure treated by hemodialysis].

Two groups of subjects were studied. The group A consisted of 40 patients treated by HD (haemodialysis) (mean age--x +/- SEM 38.6 +/- 1.47 years, duration of haemodialysis treatment 36.8 +/- 3.7 months, cuprophan dialyzers and acetate containing solution--38 mEg/l--were used, time of HD--4 hours 3 times weekly, predialysis serum creatinine was 900.8 +/- 32.1 mumol/l (10.2 +/- 0.4 mg%) postdialysis serum creatinine was 467.8 +/- 28.3 mumol/l (5.3 +/- 0.3 mg%). Patients were not treated with erythropoietin. The control group comprised 20 healthy subjects (mean age 36.7 +/- 2.7 years and serum creatinine level 76.7 +/- 3.5 mumol/l (0.9 +/- 0.1 mg%). In all examined subjects the following experimental protocol was used. In both group blood pressure (BP) and heart rate (HR) were determined at about 8 a.m. after an overnight rest. Then blood samples were withdrawn for estimation of ANP, endothelin, haematocrit value (Ht), haemoglobin (Hb) and creatinine concentrations. Between 8 and 12 a.m. all examined subjects of the group A were dialysed. After each hour of dialysis BP and HR were measured and blood samples were withdrawn ANP (Peninsula Lab.Kids.) and endothelin (Amersham Kids) were measured using RIA methods, but other biochemical parameters using routine methods. Serum creatinine and plasma ANP levels significantly decreased after HD. Plasma endothelin level was significantly higher than in the control subjects. After first hour of HD a significant decrease of plasma endothelin was observed and than plasma endothelin level started to increase. No significant correalations between creatinine, ANP and endothelin levels in examined group was observed.

Adult↗

PubMed1993

[Effect of hemodialysis on levels of parathormone in blood of patients with chronic kidney failure].

In 28 patients with chronic renal failure the concentration was determined of "MID"-"carboxyterminal" PTH fragment (M/C-PTH) and of beta-2-microglobulin in the serum during haemodialysis. It was found that the serum M/C-PTH concentration was increased significantly during haemodialysis using Cuprophane dialysers. The serum concentrations of M/C-PTH and beta-2-microglobulin were not changing significantly during the first hour of haemodialysis. The authors believe that the increase of serum M/C-PTH concentration during haemodialysis may be due to unsatisfactory biocompatibility of Cuprophane dialyzing membranes.

Adult↗

PubMed1993

[Effect of many years of hemodialysis therapy on FSH secretion induced by luliberin in men with chronic renal failure].

The purpose of the work was an explanation, what was the influence of many years of hemodialysis therapy on FSH secretion in men with chronic renal failure (CRF). The studies were carried out in 41 men with CRF treated with haemodialysis, 10 men with advanced CRF who were not dialysed, and in 15 healthy men. In all studied individuals the luliberin stimulation test (LH-RH) was performed. It was found that men with CRF, independently of the duration of hemodialysis therapy, were characterized by increased serum FSH concentration in comparison to healthy subjects. In men dialysed form over 50 months, the FSH concentration was higher than in those dialysed for a shorter time period, and not dialysed. The reaction of FSH secretion stimulated by LH-RH in men dialysed for less than 100 months and not dialysed was diminished while in those dialysed for over 100 months it was normalized.

Follicle Stimulating Hormone↗

PubMed1993

[Effect of hemodialysis on left ventricular function in patients with chronic renal failure assessment with radionuclide ventriculography].

To examine the effects of haemodialysis (HD) on left ventricular (LV) function, gated radionuclide ventriculography was conducted before and after HD in 16 patients with chronic renal failure (CRF) and in 12 healthy persons. The LV sectorial function was assessed by subdividing the LV region of interest into 6 sectors. Global ejection fraction (EF) was unchanged by dialysis (61.4 +/- 8.3% before vs. 63.5 +/- 10.4% after) (mean +/- S.D.). EF of sectors 4 and 5 was improved significantly (69.3 +/- 10.7% and 85.6 +/- 17.1% before vs. 81.7 +/- 18.4% and 97.4 +/- 22.0% after) (p < 0.05 and p < 0.05). The peak ejection rate (PER) was increased following HD (3.07 +/- 1.03 EDc/s before vs. 3.88 +/- 0.88 EDc/s after) (p < 0.02). The time to end systole (TES) corrected for R-R interval was unchanged by HD (46.3 +/- 6.3 before vs. 43.8 +/- 5.3 after). The peak filling rate (PFR) was unchanged by HD (3.41 +/- 0.77 EDc/s before vs. 3.05 +/- 0.45 EDc/s after). The time to peak filling rate (TPFR) corrected for R-R interval was increased (21.8 +/- 5.3 before vs 25.9 +/- 5.0 after) (p < 0.02). This study indicates that HD produces beneficial effects on LV systolic function in CRF patients and does not improve LV filling in early diastole.

Adult↗

PubMed1992

DNA helical stability accounts for mutational defects in a yeast replication origin.

Earlier studies on the H4 autonomously replicating sequence (ARS) identified a DNA unwinding element (DUE), a required sequence that is hypersensitive to single-strand-specific nucleases and serves to facilitate origin unwinding. Here we demonstrate that a DUE can be identified in the C2G1 ARS, a chromosomal replication origin, by using a computer program that calculates DNA helical stability from the base sequence. The helical stability minima correctly predict the location and hierarchy of the nuclease-hypersensitive sites in a C2G1 ARS plasmid. Nucleotide-level mapping shows that the nuclease-hypersensitive site at the ARS spans a 100-base-pair sequence in the required 3'-flanking region. Mutations that stabilize the DNA helix in the broad 3'-flanking region reduce or abolish ARS-mediated plasmid replication, indicating that helical instability is required for origin function. The level of helical instability is quantitatively related to the replication efficiency of the ARS mutants. Multiple copies of either a consensus-related sequence present in the C2G1 ARS or the consensus sequence itself in synthetic ARS elements contribute to DNA helical instability. Our findings indicate that a DUE is a conserved component of the C2G1 ARS and is a major determinant of replication origin activity.

Base Sequence↗

PubMed1991

Arylsulfatase A in serum from patients with cancer of various organs.

Arylsulfatase A was radioimmunoassayed in serum specimens of 96 healthy volunteers and 368 patients with histopathologically confirmed cancer of gastrointestinal tract, breast, lung, central nervous system, kidney and woman genital tract. Sensitivity, specificity and predictive value of the test were 43%, 82% and 90%, respectively, which means that a positive test is significant for diagnosis of cancer regardless of its localization. More detailed statistical analysis of the results indicates that determination of the serum concentration of arylsulfatase A might be helpful in the diagnosis of lung (59% sensitivity, 82% specificity) and central nervous system cancer (60% sensitivity, 82% specificity). Further studies should also be continued in respect to renal and women genital tract cancers for which the results of the test, although promising, are at present not conclusive due to the small numbers of examined cases. Particularly, determination of serum arylsulfatase A in case of endometrial cancer seems to be of diagnostic value. Arylsulfatase A concentration in serum with a lower than 40% sensitivity of the test cannot be considered as a valuable tumor indicator in the case of cancer of breast and gastrointestinal tract, although 80% predictive value of the test for the latter group of tumors is quite high and perhaps merits additional consideration.

Adult↗

PubMed1991

[Behavior of thyrotropic, triiodothyronine, thyroxine and cortisol hormone levels in blood serum of patients with duodenal ulcer treated with ranitidine].

Blood serum concentrations of thyrotropic hormone (TSH), triiodothyronine (T3), thyroxine (T4) and cortisol have been measured in 50 patients with duodenal ulcer. The determinations were repeated after a specific time of treatment with ranitidine: in 45 patients after 3 weeks and in 37 after additional 30 days of treatment. During the first period of treatment ranitidine was administered at a dose of 300 mg divided into two daily doses and during the second period of treatment at a single daily dose of 150 mg. A small but statistically significant changes, an increase in T3 and a decrease in TSH concentration, were observed before the treatment. No changes concerning these two parameters were found as an effect of the treatment. A decrease in the concentration of T4 was found, on the other hand, after three weeks of ranitidine administration. This decrease persisted after further 30 days of chronic treatment with ranitidine. No significant changes concerning blood serum cortisol concentration were found in any of the studied groups.

Adult↗

PubMed1990

The DNA unwinding element in a yeast replication origin functions independently of easily unwound sequences present elsewhere on a plasmid.

We have previously identified a DNA unwinding element (DUE) in autonomously replicating sequences (ARSs) and demonstrated a correlation between single-strand-specific nuclease hypersensitivity of the DUE and ARS-mediated plasmid replication in yeast. The DUE in the H4 ARS is the most easily unwound sequence in a supercoiled DNA molecule, in the context of the Ylp5 plasmid. To determine whether sequences which are more readily unwound than the ARS can influence replication activity, we have inserted such sequences, called 'torsional sinks', into the plasmids at a site distal to the ARS. We show that the torsional sink sequences effect reduction or elimination of the nuclease hypersensitivity of a variety of H4 ARS derivatives. However, we detect no difference in the in vivo replication activity of an individual ARS plasmid with or without a torsional sink. Thus, the function of the DUE in a yeast replication origin is unaffected by easily unwound sequences present elsewhere on the same plasmid.

Base Sequence↗

PubMed1990

Thermal energy suppresses mutational defects in DNA unwinding at a yeast replication origin.

Yeast replication origins contain a DNA sequence element whose biological activity correlates with hypersensitivity to single-strand-specific nucleases in negatively supercoiled plasmids. By using two-dimensional gel electrophoresis of plasmid topoisomers, we demonstrate that thermodynamically stable origin unwinding accounts for the nuclease hypersensitivity and, furthermore, that increased thermal energy facilitates stable origin unwinding in vitro. In living cells, increased thermal energy can suppress origin mutations that raise the free-energy cost for unwinding the nuclease-hypersensitive element. Specifically, mutational defects in autonomously replicating sequence (ARS)-mediated plasmid replication are less severe in cells grown at 30 degrees C as compared to 23 degrees C. Our findings indicate that the energetics of DNA unwinding at the nuclease-hypersensitive element are biologically important. We call the nuclease-hypersensitive sequence the DNA unwinding element (DUE) and propose that it serves as the entry site for yeast replication enzymes into the DNA helix.

Base Sequence↗

PubMed1990

The developmental record: reliability and validity in a clinical population.

Currently, the Developmental Record is widely used with developmentally disabled adults, at least in the midwestern and southwestern region of the United States. Since it inception in 1974, there have been no subsequent reliability and validity studies confirming its clinical usefulness. For the present study a total of 1,069 Developmental Record protocols were obtained from archival files of a large midwestern facility for mentally retarded persons. Analyses revealed high internal reliabilities, but questionable validity. Specifically, the subscale structure of the instrument was not confirmed by the factor analysis.

Disability Evaluation↗

PubMed1989

The DNA unwinding element: a novel, cis-acting component that facilitates opening of the Escherichia coli replication origin.

We have discovered that DNA supercoiling, in the absence of replication proteins, induces localized unwinding in the Escherichia coli replication origin (oriC) at the same sequence opened by the dnaA initiator protein. The DNA helix at the tandemly repeated, 13mer sequence is thermodynamically unstable, as evidenced by hypersensitivity to single-strand-specific nuclease in a negatively supercoiled plasmid, and demonstrated by stable DNA unwinding seen after two-dimensional gel electrophoresis of topoisomers. A replication-defective oriC mutant lacking the leftmost 13mer shows no nuclease hypersensitivity in two remaining 13mers and no detectable DNA unwinding on two-dimensional gels. The replication defect in the oriC mutant can be corrected by inserting a dissimilar DNA sequence with reduced helical stability in place of the leftmost 13mer. Thus, the helical instability of the leftmost 13mer, not the specific 13mer sequence, is essential for origin function. The rightmost 13mer exhibits helical instability but differs from the leftmost 13mer in its strict sequence conservation among related bacterial origins. The repeated 13mer region appears to serve two overlapping functions: protein recognition and helical instability. We propose that the cis-acting sequence whose helical instability is required for origin function be called the DNA unwinding element (DUE).

Base Sequence↗