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Biomedical subjects

J Nowak

Publications and source records attributed to J Nowak.

At least 37 records · Page 2Linked to original sources
PubMed2001

A prospective comparison between external fixation and plates for treatment of midshaft nonunions of the clavicle.

BACKGROUND AND AIMS: Several surgical techniques have been used to treat clavicular nonunions. The aim with this prospective study was to compare treatment of symptomatic midshaft clavicular nonunions with either external fixation or plating. PATIENTS AND METHODS: The study included two consecutive series where the first 11 patients (8 men and 3 women) were treated with external fixation (EF) while the following 13 patients (5 men and 8 women) were treated with internal fixation using a 3.5 mm reconstruction plate (RP). All patients had autologous cancellous bone graft. After on average 8.6 years (EF) and 5.4 years (RP), respectively, an independent observer evaluated the patients. RESULTS: In the EF-group 8/11 healed within 12 months while 3/11 healed after reoperation with a reconstruction plate and new bone grafting at 6-9 months. In the RP-group 12/13 healed within six months while 1/13 healed after two additional bone transplants. There was no hardware breakage. The healing time for the RP group was significant shorter when compared with the EF group even if the fractures that did not heal after the first operation were excluded. In 4 patients the plate was removed following healing. There was no significant difference in functional outcome between groups at follow up. CONCLUSION: The reconstruction plate was a better alternative than external fixation due to faster and more reliable healing. Patients commonly considered the external frame cumbersome.

Adolescent↗
PubMed2001

Determination of carbon monoxide in blood by means of microdiffusion.

There was developed a little-work-consuming and non-expensive microdiffusion method of carboxyhaemoglobin determination in blood, in low range concentration. It can be used in the assessment of passive smokers' exposure to carbon monoxide. The amount of blood necessary for the determination was 0.15 ml. An average precision of the developed method of the carbon monoxide determination (converting into HbCO) for the concentration ranged from 1 to 5%, from 3 to 12% and from 5 to 20% was respectively 5.96, 4.09 and 2.14.

Blood Gas Analysis↗
PubMed2001

Significance of molecular identification of hepatitis C virus RNA in diagnosis of cryptogenic hepatitis in children.

Viral etiology of hepatitis is routinely proved by standard immunological tests detecting specific antibodies. However, identification of specific antibodies cannot always be conclusive. Since specific hepatitis C virus (HCV) antibodies may appear after some months of the infection, identification of HCV RNA and/or hepatitis G virus (HGV) RNA should clarify the etiology of hepatitis. The aim of this study was to diagnose etiologically unknown hepatitis by a reverse transcription-polymerase chain reaction (RT-PCR) testing of the presence of HCV RNA and HGV RNA. The study involved 33 children with histologically proved hepatitis. The presence of HCV and any signs of autoimmune disease were not observed at the beginning of the follow-up study. During 2.5 years of the follow-up HCV-RNA was found in the blood and liver biopsies in 17 patients. Eight of them became HCV antibodies-positive during the follow-up. None of them eliminated the virus from the blood during the follow-up. In two other patients HCV-RNA was found only in the liver. HGV infection in all cryptogenic patients was excluded by PCR testing. Identification of HCV RNA RT-PCR allowed to diagnose 19 out of 33 (57.6%) patients with cryptogenic hepatitis. The etiology of the hepatitis in remaining 12 patients has to be established.

Child↗
PubMed2001

Hepatitis G virus co-infection may affect the elimination of hepatitis C virus RNA from the peripheral blood of hemodialysis patients.

Hemodialysis patients are at risk for hepatitis C virus (HCV) and hepatitis G virus (HGV) infection. The aim of this study was to investigate the possible influence of HGV co-infection on HCV RNA elimination from the peripheral blood of hemodialysis patients. The study involved 144 persons, all with HCV antibodies and HCV RNA. Among 144 patients 24 (16.7%) were positive for HGV RNA. After 2.5 years of observation 80 patients (55.6%) were still HCV RNA-positive. In the latter group 18 patients were co-infected with HGV and 62 were HGV RNA-negative. During 2.5 years of the follow-up study 64 patients eliminated HCV RNA from the serum. In this group only 6 patients were HGV co-infected. None of the HGV-positive patients eliminated HGV RNA from the serum. The higher incidence of HGV co-infection in the group of patients who remained HCV RNA-positive (18/80, 22.5%), in comparison to the group of HCV antibodies-positive patients who lost HCV in the blood (6/64, 9.4%, P < 0.0001) suggests, that the co-infection with HGV may delay the spontaneous elimination of HCV RNA from the blood.

Adult↗
PubMed2001

Limited pattern of TCR delta chain gene rearrangement on the RNA level in multiple sclerosis.

Susceptibility to multiple sclerosis (MS) is most likely affected by a number of genes, including HLA and T-cell receptor (TCR) genes. T cells expressing gamma/delta receptors seem to contribute to autoagression in MS, as evidenced by their localization in the MS plaques in the brain. The aim of this study was to analyse the TCRdelta chain gene rearrangement at the RNA (cDNA) level and compare to the DNA pattern rearrangement. TCRdelta gene rearrangement was analysed in MS patients and healthy individuals with the use of primers specific for Vdelta1-6 and Jdelta1 genes (at the DNA level) and specific for Vdelta1-6 and Cdelta1 genes (at the cDNA level). The size of PCR products was analysed on agarose gel and by ALF-Express (Pharmacia). Additionally, the lymphocyte surface immunophenotype was studied with specific monoclonal antibodies. At the DNA level a restricted pattern of Vdelta3-Jdelta1 and Vdelta5-Jdelta1 was found only in MS patients. Contrary to DNA, mono-, oligoclonal RNA (cDNA) rearrangements were limited to Vdelta1-Cdelta1, Vdelta2-Cdelta1 and Vdelta3-Cdelta1 only in MS patients as well. Surface immunophenotype analysis revealed in MS a much higher frequency of activated gamma/delta T lymphocytes, i.e. expressing HLA-DR and CD25. An elevated level of CD56 positive cells in MS was recorded. Mono-oligoclonal pattern of TCRdelta gene rearrangement at the RNA level, along with increase in activated gamma/delta T cells, strongly argue for a significant role of gamma/delta T lymphocytes in the pathogenesis of MS.

Journal Article↗
PubMed2001

[Genetic determination of smell].

The recent study of olfactory receptor genes sheds new light on the significance of this receptor not only for smell recognition but also in human embryogenesis. In this work current data concerning the role of olfactory receptors in human as well as their genetic determination are presented. Olfactory receptors are encoding approximately by 1000 hOR genes. The hOR gene family is most likely the largest in human genome. Among 1000 hOR genes, 347 are functional, the rest 70% being pseudogenes are not expressed. HOR genes reside at 25 locations in human genome in multiple clusters on all human chromosomes, except 2, 4, 18, 20, 21, and Y. Each receptor recognizes single as well as multiple odorant, and each odorant binds to multiple receptors to generate specific activation patterns for each of a great number of distinct smells. There is more and more evidence showing close correlation between HLA complex and smell recognition, which influence mating behavior in animals, consequently leading to increase immune response to various pathogens. The last investigations showed hOR expression in germinal cells and in developing embryo, suggest that hOR may play functional role in cell recognition in organogenesis.

Animals↗
PubMed2000

Enhancement of in vitro growth and resistance to gray mould of Vitis vinifera co-cultured with plant growth-promoting rhizobacteria.

The potential of a plant growth-promoting rhizobacterium, Pseudomonas sp. (strain PsJN), to stimulate the growth and enhancement of the resistance of grapevine (Vitis vinifera L.) transplants to gray mould caused by Botrytis cinerea has been investigated. In vitro inoculation of grapevine plantlets induced a significant plant growth promotion which made them more hardy and vigorous when compared to non-inoculated plantlets. This ability increased upon transplanting. When grown together with B. cinerea, the causal agent of gray mould, significant differences of aggressiveness were observed between the inoculated and non-inoculated plants. The presence of bacteria was accompanied by an induction of plant resistance to the pathogen. The beneficial effect from this plant-microbe association is being postulated.

Botrytis↗
PubMed2000

The aetiology and epidemiology of clavicular fractures. A prospective study during a two-year period in Uppsala, Sweden.

In a prospective study, the age- and gender-specific incidence and features of clavicular fractures were studied during 1989 and 1990. The population at risk consisted of about 200,000 individuals aged 15 or above in the county of Uppsala, Sweden. There were 187 clavicular fractures in 185 patients corresponding to an annual incidence of 50/100,000 (males 71/100,000, women 30/100,000). Males were significantly younger and sustained comminuted fractures more often than women. The fracture incidence decreased with age in both genders, although the reduction was significant only in men. Bicycle accidents most frequently caused clavicular fractures in both genders, whereas sports activities were significantly more common in men. Right and left clavicles were almost as frequently fractured, and a direct fall on the shoulder was the most frequent mechanism of injury for both genders. There was no difference between genders in the anatomical location with about three of four fractures occurring through the middle part and one of four through the acromial part of the clavicle. Ninety-five percent healed uneventfully, while non-union developed in 5% - evenly distributed between the middle part of the clavicle and the acromial part.

Accidents, Traffic↗
PubMed2000

Validation of a LC method for the determination of 5-aminosalicylic acid and its metabolite in plasma and urine.

The choice of a proper analytical method for the quantification of drugs and/or their metabolites in biological samples plays a significant role in the evaluation and interpretation of bioavailability, bioequivalence and pharmacokinetic data. The aim of this study was validation of a method for the identification and quantitative determination of 5-aminosalicylic acid (5-ASA) and its metabolite N-acetyl-5-aminosalicylic acid in human plasma and urine. According to previous studies on the disposition of 5-ASA (mesalazine) in a patient with inflammatory bowel diseases, we have developed a rapid, sensitive method for the determination of 5-ASA and its acetylated metabolite, N-acetyl-5-aminosalicylic acid (Ac-5-ASA). The advantage of this method is that it measures both compounds, and is more rapid, reproducible and credible than the previous studies [C. Fischer, K. Maier, U. Klotz, J. Chromatogr. Biomed. Appl. 225 (1981) 498-503; P.N. Shaw, A.L. Sivner, L. Aarons, J.B. Houston, J. Chromatogr. Biomed. Appl. 274 (1983) 393-397; B. Norlander, R. Gotthard, M. Strom, Aliment. Pharmacol. Ther. 3 (1989) 333-342; U. Klotz, G.L. Stracciari, Arzneim.-Forsch. Drug Res. II 43 (12) (1993) 1357-1359]. 5-ASA was quantitatively determined in human plasma and urine samples by liquid chromatography following prior derivatization to its acetylated metabolite (Ac-5-ASA). N-Acetyl-anthranilic acid was used as the internal standard. The detection was performed with a spectrofluorimetric detector, excitation at 311 nm, cut-off at 449 nm. The method was validated for the following parameters: linearity, recovery, sensitivity, precision, accuracy, selectivity and stability, limits of quantification and of detection. It showed good linearity (r2 > or = 0,996) in the range 0.1 ng/ml to 8 microg/ml using a Lichrospher 60 RP-select B column. The lower limit of detection was 20 ng/ml in plasma and urine. The within-run relative standard deviations (R.S.D.) were below 6.7% at all concentration levels and the between-run R.S.D. were below 25.4% at all concentration levels.

Adult↗
PubMed2000

Beat-to-beat QRS amplitude variability in elite endurance athletes.

Results from variance electrocardiography, displaying the wide-band, phase-locked electrical micro-variability during the depolarization phase, was analysed versus clinical data, echocardiographic structural and functional variables and myocardial scintigraphic findings in 174 elite orienteers compared with 37 age-matched elite endurance athletes and 50 age-matched, healthy medical students. PCA analysis identified a subgroup of five orienteers deviating from the rest of the study group and both control groups with regard to their QRS amplitude variability. No correlations were found between pathology by medical history or any of the echocardiographic and scintigraphic variables or by the variance electrocardiographic aberrations in any of the groups studied.

Adolescent↗
PubMed2000

The Doa4 deubiquitinating enzyme is functionally linked to the vacuolar protein-sorting and endocytic pathways.

The Saccharomyces cerevisiae DOA4 gene encodes a deubiquitinating enzyme that is required for rapid degradation of ubiquitin-proteasome pathway substrates. Both genetic and biochemical data suggest that Doa4 acts in this pathway by facilitating ubiquitin recycling from ubiquitinated intermediates targeted to the proteasome. Here we describe the isolation of 12 spontaneous extragenic suppressors of the doa4-1 mutation; these involve seven different genes, six of which were cloned. Surprisingly, all of the cloned DID (Doa4-independent degradation) genes encode components of the vacuolar protein-sorting (Vps) pathway. In particular, all are class E Vps factors, which function in the maturation of a late endosome/prevacuolar compartment into multivesicular bodies that then fuse with the vacuole. Four of the six Did proteins are structurally related, suggesting an overlap in function. In wild-type and several vps strains, Doa4-green fluorescent protein displays a cytoplasmic/nuclear distribution. However, in cells lacking the Vps4/Did6 ATPase, a large fraction of Doa4-green fluorescent protein, like several other Vps factors, concentrates at the late endosome-like class E compartment adjacent to the vacuole. These results suggest an unanticipated connection between protein deubiquitination and endomembrane protein trafficking in which Doa4 acts at the late endosome/prevacuolar compartment to recover ubiquitin from ubiquitinated membrane proteins en route to the vacuole.

Adenocarcinoma↗
PubMed1999

The Saccharomyces cerevisiae ubiquitin-proteasome system.

Our studies of the yeast ubiquitin-proteasome pathway have uncovered a number of general principles that govern substrate selectivity and proteolysis in this complex system. Much of the work has focused on the destruction of a yeast transcription factor, MAT alpha 2. The alpha 2 protein is polyubiquitinated and rapidly degraded in alpha-haploid cells. One pathway of proteolytic targeting, which depends on two distinct endoplasmic reticulum-localized ubiquitin-conjugating enzymes, recognizes the hydrophobic face of an amphipathic helix in alpha 2. Interestingly, degradation of alpha 2 is blocked in a/alpha-diploid cells by heterodimer formation between the alpha 2 and a1 homeodomain proteins. The data suggest that degradation signals may overlap protein-protein interaction surfaces, allowing a straightforward steric mechanism for regulated degradation. Analysis of alpha 2 degradation led to the identification of both 20S and 26S proteasome subunits, and several key features of proteasome assembly and active-site formation were subsequently uncovered. Finally, it has become clear that protein (poly) ubiquitination is highly dynamic in vivo, and our studies of yeast de-ubiquitinating enzymes illustrate how such enzymes can facilitate the proteolysis of diverse substrates.

Amino Acid Sequence↗
PubMed1999

ESR study of plasmatic membrane of the transplantable melanoma cells in relation to their biological properties.

Using the spin labelling method we studied changes in the structure and dynamics of molecular mobility in the plasmatic membrane accompanied by a spontaneous alteration of a melanotic melanoma line into an amelanotic form with a higher growth rate, changed antigenicity and immunogenicity. The calculated ratio of the low-field line (A) intensity to the central line (C) intensity of the spectrum showed statistically significant differences in the order of parameters in the plasmatic membranes of both forms of melanocytes. The significantly broader central line (deltaW0) in the spectra of labelled amelanotic melanoma cells than in the original cell line indicated changes in the membrane structure leading to a lowering of the degree of order in the phospholipid bilayer. It has been suggested that a progression of transplantable melanomas is accompanied by an increase in membrane fluidity and reduction in molecular mobility dynamics within it.

Animals↗
PubMed1999

Ipamorelin, a new growth-hormone-releasing peptide, induces longitudinal bone growth in rats.

Ipamorelin is a new and potent synthetic pentapeptide which has distinct and specific growth hormone (GH)-releasing properties. With the objective of investigating the effects on longitudinal bone growth rate (LGR), body weight (BW), and GH release, ipamorelin in different doses (0, 18, 90 and 450 microg/day) was injected s.c. three times daily for 15 days to adult female rats. After intravital tetracycline labelling on days 0, 6, and 13, LGR was determined by measuring the distance between the respective fluorescent bands in the proximal tibia metaphysis. Ipamorelin dose-dependently increased LGR from 42 microm/day in the vehicle group to 44, 50, and 52 microm/day in the treatment groups (P<0.0001). There was also a pronounced and dose-dependent effect on BW gain. The treatment did not affect total IGF-I levels, IGFBPs, or serum markers of bone formation and resorption. The number of tartrate-resistant acid phosphatase-positive multinuclear cells in the metaphysis of the tibia did not change significantly with treatment. The responsiveness of the pituitary to a provocative i.v. dose of ipamorelin or GHRH showed that the plasma GH response was marginally reduced (P<0.03) after ipamorelin, but unchanged after GHRH. The pituitary GH content was unchanged by ipamorelin treatment. Whether ipamorelin or other GH secretagogues may have a place in the treatment of children with growth retardation requires demonstration in future clinical studies.

Animals↗
PubMed1999

Diversity of V delta-J delta gene rearrangement in peripheral blood lymphocytes and intrathecal IgG synthesis in multiple sclerosis.

The object of the study is a comparison of intrathecal IgG synthesis and gamma/delta TCR genes rearrangement in multiple sclerosis. The subgroup of 13 cases with intrathecal IgG synthesis and positive oligoclonal bands was compared with 8 cases with IgG index below 0.75 and with undetectable oligoclonal bands. TCR gene rearrangement was studied in peripheral blood lymphocytes by PCR analysis. In majority of cases of the first group the V delta-J delta junctional repertoire was restricted as evidenced by oligoclonal rearrangement. Monoclonal pattern of rearrangement was also established in some cases concerning V delta 1-J delta 1 and V delta 5-J delta 1. In all cases with one exception, demonstrating IgG index < 0.75 and with negative oligoclonal bands in CSF the oligo- or polyclonal pattern of V delta-J delta gene rearrangement was noticed. It is therefore suggested that subset T and B lymphocytes may undergo clonal expansion in MS as evidenced by restricted pattern of V delta-J delta rearrangement and intrathecal oligoclonal IgG synthesis, respectively. Oligoclonal expansion at certain B and T cells may occur due to stimulation by an antigen related to MS pathogen.

Antibodies, Monoclonal↗
PubMed1999

[Surgical intraduodenal drainage of bile duct: an introductory report].

UNLABELLED: Reconstructing operations, performed on extrahepatic bile ducts, usually need protection of anastomosis by means of drainage. Classic Kehr's drainage is loaded with the risk of complications. Since 1993 the authors have been applying the alter way of drainage: an intraduodenal drainage by endoprothesis Y (DEY). Endoscopical removal of the drain was performed in 3-4 months after the operation. This way of drainage was used between III 1993--V 1997 in 23 patients. We did not observed any complications or pancreas reactions. Clinical control of patients was made after operation with ECW. In 4 cases the results of treatment were unsuccessful. In other 16 patients results of performed operations were favourable. CONCLUSION: Proposed way of protection of bile duct's reconstruction's site using DEY decreases the number of complications connected with classic Kehr's drainage.

Adult↗