Biomedical subjects

M Kos

Publications and source records attributed to M Kos.

At least 19 recordsLinked to original sources

PubMed2006

Carbon dioxide differentially affects the cytokine release of macrophage subpopulations exclusively via alteration of extracellular pH.

BACKGROUND: The improved outcome after endoscopic surgery has been attributed to less surgical trauma. However, the underlying mechanisms are not fully understood, and direct effects of CO2 used for pneumoperitoneum, cellular acidification, and/or the lack of air contamination have been postulated to additionally modulate immune functions during endoscopic surgery. We investigated the effects of CO2 incubation, extracellular acidification, and air contamination on the inflammatory response of two distinct macrophage populations. METHODS: R2 and NR 8383 rat macrophage cell lines were used. Interleukin-6 (IL-6) and nitric oxide after lipopolysaccharide (LPS) stimulation were determined in these sets of experiments: incubation in 100% CO2, 5% CO2, and room air for 2h; incubation at pH 7.4, 6.5, and 5.5 for 2 h in 5% CO2; and incubation in 100% CO2, 5% CO2 and room air in fixed pH 6.3. The extracellular pH was monitored during incubation. We determined the alteration of intracellular pH in cells subjected to extracellular acidification by fluorescence microscopy. RESULTS: Extracellular pH decreased to 6.3 during 100% CO2 incubation. IL-6 release was reduced after CO2 incubation in NR 8383 cells and increased in R2 cells (p < 0.05). It was not altered by air incubation. Decreasing the extracellular pH to 6.5 mimicked the effects of CO2 and a decrease to 5.5 suppressed IL-6 release in both cell lines. In fixed pH at 6.3, CO2 and air incubation had no effect. CO2 and pH had no impact on nitric oxide release and vitality. Intracellular pH decreased with extracellular acidification without significant difference between the two cell lines. CONCLUSIONS: A decrease in extracellular pH during incubation in CO2 differentially affects IL-6 release in macrophage subpopulations. This may explain contradictory results in the literature. Moreover, we demonstrated that air contamination does not affect macrophage cytokine release. The decrease in extracellular pH is the primary underlying mechanism of the alteration of macrophage cytokine release after CO2 incubation, and it appears that the ability to maintain intracellular pH is not determined by the effects of CO2 or extracellular acidification.

Animals↗

PubMed2006

Insitu bioaugmentation of nitrification in the regeneration zone: practical application and experiences at full-scale plants.

Nitrification is the rate-limiting process in the design of activated sludge process. It is especially unstable during the winter season (when the temperature of activated sludge mixed liquor drops below 13 degrees C). It is therefore difficult to meet the ammonia effluent standards in winter. The common way to compensate for low nitrification rates at low temperatures is to increase sludge retention time (SRT). However, the increase of SRT is accompanied by negative factors such as elevated sludge concentration, higher sludge loading of secondary clarifiers, formation of unsettleable microflocs, etc. The low performance of nitrification at low temperatures can also be compensated for by enhancing the nitrification population in activated sludge. This paper describes such a method called bioaugmentation of nitrification in situ. This procedure takes place in a so-called regeneration tank, which is situated in the return activated sludge stream. The results of the operation of two wastewater treatment plants with regeneration zones are described in this paper, together with some economic evaluation of the bioaugmentation method.

Czech Republic↗

PubMed2005

Renal artery changes in patients with primary renal cell carcinoma.

Arterial fibromuscular dysplasia (FMD) is a noninflammatory, nonatherosclerotic, occlusive condition of the systemic arteries, most frequently affecting renal arteries. Renal cell carcinoma (RCC) might be associated with arterial hypertension; however, there are no data in the literature regarding the relationship between RCC and associated renal artery changes. We analyzed a consecutive series of 57 (35 male and 22 female) patients aging from 35 to 79 years (mean 58.9 years) who underwent nephrectomy due to RCC in the year 2003. The patients had RCC measuring from 2 to 16 cm (mean 7.1 cm). Specimens were routinely fixed, embedded in paraffin, cut, and stained with hematoxylin and eosin, Mallory trichrome method, and orcein. Renal arteries of 26 patients (20 male, 6 female) showed no changes. In these patients, RCC measured 2.5-11 cm in largest diameter (mean 6.6 cm). In 24 patients (10 male, 14 female), renal arteries showed FMD. RCCs in these patients measured between 2 and 16 cm (mean 8.0 cm). Seven patients had atherosclerotic changes in renal arteries. In this series, FMD was found in a significant proportion of patients with RCC, mainly in women. The cause of such changes and their relationship with RCC and systemic hypertension should be further analyzed.

Adult↗

PubMed2005

Hemispheric asymmetry, modular variability and age-related changes in the human entorhinal cortex.

The verrucae areae entorhinalis (VAE) are a characteristic feature of the human brain that occupy the anterior and posterolateral parts of the parahippocampal gyri and correspond to the islands of layer II neurons. We analyzed VAE in 60 neurologically normal subjects ranging from 23 to 85 years of age using a casting method. In 10 of these subjects the total number of neurons in the entorhinal islands was estimated stereologically using the optical fractionator. The number and surface area of VAE were higher in the left hemisphere compared with the right, and this leftward asymmetry was highly significant. Regression analysis showed a negative correlation between average VAE area and age in both hemispheres, representing a rate loss of about 800 microm2 per year. The estimated number of neurons obtained with the optical fractionator showed no significant difference between the left and the right hemisphere (468,000+/-144,000 vs. 405,000+/-117,000). There was a highly significant negative correlation between neuron numbers and age in both sides. In addition, clusters of small, undifferentiated layer II neurons ('heterotopias') were frequently observed in the rostral part of the entorhinal cortex in young and elderly adults. Layer II entorhinal neurons are among the first to show neurofibrillary changes during normal aging. The present data confirm the occurrence of age-related neuron loss in the entorhinal cortex. Considering the consistent projections from ipsilateral auditory association areas that, together with Broca's motor-speech area (Brodmann areas 44 and 45), show leftward asymmetry from early infancy (such as Brodmann area 22, planum temporale, and area 52 in the long insular gyrus), we speculate that functional lateralization of the human entorhinal cortex may be associated with specialization for memory processing related to language. Due to the dependence of hippocampal formation on entorhinal projections, this finding is also consistent with the greater capacity of the left hippocampus for verbal episodic memory.

Adult↗

PubMed2004

Prostaglandin F2alpha supplemented semen improves reproductive performance in artificially inseminated sows.

The objective of this study was to assess the effects of the addition of prostaglandin F2alpha (PGF2alpha) to semen, to increase reproductive performance in sows. Sows in 11 large production units, were inseminated (AI) either with PGF2alpha enriched fresh semen (group 1, n=1258) or with untreated fresh semen (group 2, n=1101). Conception rate, regular return to estrus, farrowing rate, subsequent total and live-born litter size, subsequent weaning to estrus intervals, pigs born and pigs weaned per sow per year were evaluated. Conception and farrowing rates, as well as regular returns to estrus were altered beneficially (P<0.001) with PGF2alpha supplemented semen. Subsequent total-born (P<0.06) and subsequent live-born (P<0.15) litter size, as well as subsequent weaning to estrus intervals (P<0.22), were not affected to the same extent. Total pigs born (P<0.05) and pigs weaned (P<0.04) per sow per year were increased by using PGF2alpha supplemented semen.

Animals↗

PubMed2004

Expression of the proliferating cell nuclear antigen and protein products of tumour suppressor genes in the human foetal testis.

Tumour suppressor genes retinoblastoma (Rb1) and adenomatous polyposis coli (Apc) as well as the proliferating cell nuclear antigen (PCNA) are involved in embryonic development. The purpose of the present study was to investigate the expression of Rb1 protein, APC protein and PCNA during development of the human foetal testis. Qualitative analysis of their expression at the single-cell level was performed using immunohistochemistry on archive samples of the foetal testis (18-37 gestation week). Stereological parameters (volume density, absolute volume, numerical density, absolute number) were calculated for quantification of the overall expression of those proteins that were expressed frequently enough for such an analysis. PCNA was frequently expressed in nuclei of immature Sertoli cells and prospermatogonia and less frequently in surrounding peritubular (myoid) and interstitial cells. The pRb1 protein was present in nuclei of prospermatogonia and Sertoli cells but was absent from the interstitial tissue. APC protein was expressed in the cytoplasm of a very small number of prospermatogonia and interstitial (Leydig) cells. The overall expression of PCNA in all stages of development was higher than pRb1 expression.

Adenomatous Polyposis Coli Protein↗

PubMed2003

Antenatal detection of mosaic trisomy 9 by ultrasound: a case report and literature review.

This paper presents a fetus with mosaic trisomy 9 diagnosed by chorionic villus sampling and confirmed by cordocentesis, and compares this case with published cases in order better to define the ultrasound markers confined to trisomy 9 syndrome. Detailed fetal ultrasound examination was carried out, revealing shortened femur, placental cysts and oligohydramnios. All published trisomy 9 cases with abnormal ultrasound findings were extracted from the MEDLINE database in the period from 1973 to 2002. We found 12 non-mosaic and 13 mosaic cases, including our case. The most frequent ultrasound abnormalities included characteristic cardiac, skeletal, craniofacial and central nervous system malformations. Intrauterine growth restriction and single umbilical artery were prevalent non-specific findings in both non-mosaic and mosaic groups. Parental chromosomal variations, as in our case, were not uncommon findings. When a fetus shows structural anomalies suggesting the presence of trisomy 9, karyotyping should be performed on both chorionic villi or amniocytes and fetal blood lymphocytes to enable a correct diagnosis to be made.

Adult↗

PubMed2003

The influence of locally implanted high doses of gentamicin on hearing and renal function of newborns treated for acute hematogenous osteomyelitis.

BACKGROUND: [corrected] Osteomyelitis and arthritis still present a serious diagnostic and therapeutic problem. Difficulties arise in particular in the treatment of acute hematogenic osteomyelitis (AHO) in newborns where mega-doses of gentamicin are administered locally for about 3 weeks. Gentamicin possesses strong oto- and nephrotoxicity and the occurrence of these adverse effects depends on the duration of treatment and the serum drug concentration. OBJECTIVE: Aim of the study was to evaluate the influence of local gentamicin application on auditory and kidney functions. MATERIAL AND METHODS: Twenty newborns (14 boys and 6 girls) with AHO were treated at the Department of Pediatric Surgery, Marciniak Hospital, Wroclaw, Poland, by local implantation of miniseptopal or gentamicin sponge. Serum urea, creatinine, antibiotic concentrations and NAG activity/g creatinine ratio in urine were estimated before and 1, 4, 8, 16 days after the operation and compared to values in the control group. Brainstem-evoked auditory potentials (BAEP) were examined before, during the first 3 weeks, and 6-11 months after gentamicin implantation. RESULTS: Mean gentamicin serum concentrations were: 0.67 +/- 0.98 mg/l on the 1st day, 0.16 +/- 0.37 mg/l on the 4th day, 0.03 +/- 0.09 mg/l on the 8th day, 0.01 +/- 0.03 mg/l on the 16th day after operation and did not exceed the upper limit of the therapeutic range. N-acetyl-beta-D-glucosaminidase (NAG)/g creatinine in urine ratios were satisfactory: 77.91 +/- 36.22 UI/g before the operation, 146.51 +/- 82.27 UI/g on the 4th, 162 +/- 111 UI/g on the 8th, 168 +/- 59.83 UI/g on the 16th day after operation and were statistically significantly (p < 0.05) higher than values in the control group. Serum urea and creatinine levels were in the normal range in all groups. Initial BAEP were well in the normal range in 15 of 16 children before treatment and in 14 of 16 children after treatment. CONCLUSIONS: Locally applied gentamicin as miniseptopal or sponge in newborns produces gentamicin concentrations close to the minimal therapeutic serum concentration which are present over a prolonged period. The raised NAG values in urine and normal serum urea and creatinine levels during treatment with gentamicin without concomitant clinical symptoms of renal failure suggest subclinical destruction of the renal tubules. Lack of change in BAEPs shows that there is no impairment of auditory function.

Acetylglucosaminidase↗

PubMed2002

Human estrogen receptor-alpha: regulation by synthesis, modification and degradation.

This review aims to evaluate the impact that human estrogen receptor-alpha (ER-alpha) synthesis, modification and degradation has on estrogen-dependant physiological and pathological processes within the body. Estrogen signaling is transduced through estrogen receptors, which act as ligand-inducible transcription factors. The significance of different isoforms of ER-alpha that lack structural features of full-length ER-alpha are discussed. The influence of differential promoter usage on the amount and isoform of ER-alpha within individual cell types is also reviewed. Moreover, the potential role of phosphorylation, ubiquitination and acetylation in the function and dynamic turnover of ER-alpha is presented.

Acetylation↗

PubMed2002

Midfacial fractures in children.

The purpose of the study was to present a modern classification and discuss the treatment of midfacial fractures in children. From the beginning of 1 January 1998 to 31 October 2000, 147 children were treated for different craniofacial fractures. Among them 28 patients (19 %) had extensive midfacial fractures complicated by impaired vision and/or CNS dysfunction and were treated surgically. The fractures were divided into: zygomatico-orbital (1 pt) and zygomatico-orbito-maxillary (5 pts), isolated orbital wall fractures (14 pts) and naso-orbital dislocations (2 pts), upper facial portion dislocations (2 pts) and fronto-naso-orbital (2 pts) or cranio-orbital fractures (2 pts). Clinical examination revealed mainly dysfunction of facial morphology and aesthetics (enophthalmos, telecanthus), CSF leakage, impairment of vision and restricted eyeball movements. Ophthalmological, neurological and radiological (Waters view, CT, NMR) examinations were performed in all cases. The treatment consisted of bone repositioning, reconstruction with autologous bone grafts and three-dimensional stabilisation using titanium plates. Twenty-three pts were operated on before and 5 pts after 7th day after trauma. The restoration of normal facial morphology was achieved in 26 patients. In 2 cases it was impossible because of the destruction of soft tissue and an extremely extensive bony trauma. Better reposition of bony fragments, prompt healing and better final results were achieved in patients operated before day 7 after trauma. Achieving good results in midfacial fractures requires prompt and adequate treatment and a multidisciplinary (paediatric, maxillofacial, plastic surgeons, neurosurgeon, ophthalmologist) team.

Bone Plates↗

PubMed2002

Perspectives of clinical application of bone morphogenetic proteins in children.

UNLABELLED: The purpose of the study was to modify the method of Bone Morphogenetic Protein (BMP) extraction from bovine bones, estimate the osteoinductive potential of the extracted protein fractions in relation to the degree of protein purity and to test collagen formed in porous discs as a carrier. It was required before BMP application in reconstructive surgery in children. MATERIAL AND METHOD: BMP preparation from bovine bones was conducted according to a modification of Luyten's method. Three fractions of different degree of purity - demineralised bone matrix "M", extract "E", and fraction after hydroxyapatite column "HP" - were tested for their osteoinductive potential. They were implanted on a collagen carrier into the right rat femoral muscle pouch. Controls were implanted in the same way in the left muscle pouch. The discs were removed after 3 and 6 weeks and tested for alkaline phosphatase activity, a marker of new bone formation. RESULTS: Out of the 10 animals used for testing the osteoinductive potential of matrix fraction, 7 results were positive and 3 negative. In the case of the extract fraction, the analysis was conducted for 3 weeks on 9 rats and 6 weeks on 13 rats. Six and 11 positive results were obtained, respectively. In the HP group 5 animals were observed for 3 weeks (3 positive, 2 negative) and 10 animals for 6 weeks (7 positive, 3 negative). In the case of the extract, the differences in alkaline phosphatase activity after 6 weeks were statistically significant (p <or= 0.05) compared to controls. In the other groups, a positive tendency was observed, but it was not statistically significant. CONCLUSIONS: Purified BMP has osteoinductive abilities causing ectopic new bone formation. From all obtained BMP fractions the extract had the highest osteoinductive potential and seems to be an optimal fraction for further clinical use. These results offer hope for a prompt clinical application of nonantigenic, xenogenic BMP, especially in three-dimensional bone reconstruction, for the treatment of non-united fractures or fractures with delayed union, to fill either bone cysts or other defects.

Alkaline Phosphatase↗

PubMed2002

Down but not out? A novel protein isoform of the estrogen receptor alpha is expressed in the estrogen receptor alpha knockout mouse.

The mouse knockout of the estrogen receptor alpha (ERalpha) gene, known as alphaERKO, has been extensively used for several years to study the role and function of ERalpha. Residual estradiol binding capacity in uterine tissue of 5-10% raised doubts if this knockout is a genuine null mutation of ERalpha. Although alternatively spliced ERalpha mRNA variants in the alphaERKO mouse were reported previously, the corresponding protein isoforms have not been detected to date. Here we show that a variant ERalpha protein, 61 kDa in size, is expressed in the uterine tissue of alphaERKO mice as a result of an alternative splicing. The transactivation capability of this protein is cell dependent and can be as high as 75% of the wild type ERalpha.

3T3 Cells↗

PubMed2001

Tissue-specific expression of human ERalpha and ERbeta in the male.

The important role of estrogens in women in physiological and pathological processes is well accepted, but recently it has become evident that estrogens are also important in male physiology, in particular, within bone metabolism and reproduction. Consequently, it is necessary to identify and to characterize the molecular mechanisms of estrogen action in order to evaluate how the pleiotropic effects of estrogens are mediated in a variety of tissues. We have recently shown that human estrogen receptor alpha (ERalpha) mRNA is transcribed from at least six different promoters (1A-1F). Transcription of ERalpha in bone is exclusively dependent on the F-promoter. To study the regulation of ER expression in this tissue, we examined 1 kbp of the F-promoter region of human ERalpha, which is located more than 70 kbp upstream of the transcription start site of the ERalpha gene. Transient transfection experiments demonstrated a basal activity from the F-promoter, which was further increased when ERalpha was cotransfected. We have shown recently that the F-promoter can give rise to at least two ERalpha isoforms in bone. On the contrary, ERbeta expression in primary osteoblasts is extremely low, indicating that this ER isoform plays only a minor role in these cells. In contrast to bone, we have demonstrated that both ERalpha and ERbeta transcripts are readily detected in testis. Here, we report that besides ERalpha, ERbeta transcripts can give rise to two protein isoforms and that this complex situation could have important functional consequences for the signalling of estrogens and their analogs.

Alternative Splicing↗

PubMed2001

Systemic conditions for performance of pharmacoepidemiologic studies in Slovenia.

In Slovenia, the national health insurance system covers almost the whole population. The average patient receives six to seven prescriptions per year with an average value of 15 USD per prescription. This paper presents the systemic conditions necessary for the performance of pharmacoepidemiologic studies. A recent study addressing the use of antiepileptic drugs is an example. The current law on Personal Data Protection, which is compliant with EU Directive 95/46/EC, prevents infringement of personal integrity resulting from inappropriate use of personal data or inappropriate management and use of databases containing personal data. Since July 2000, the Law on Health Care Related Databases has defined the databases and the ways data can be acquired, processed, transferred, and exchanged among persons authorized to perform health care services. When gathering additional data not currently contained in the health care-related databases defined by the law, written consent from participants is required, and study documentation must be submitted for approval to the national Medical Ethics Committee. The main legislation covering clinical and pharmacoepidemiologic research is the Medicinal Products and Medical Devices Act of 1999, together with its by-laws, which is also in accordance with EU Directives.

Bioethics↗

PubMed2001

Immunocytochemical demonstration of visual pigments in the degenerate retinal and pineal photoreceptors of the blind cave salamander (Proteus anguinus).

Visual pigments in the regressed eye and pineal of the depigmented neotenic urodele, the blind cave salamander (Proteus anguinus anguinus), were studied by immunocytochemistry with anti-opsin antibodies. The study included light- and electron-microscopic investigations of both the eye and the pineal organ. A comparison was made with the black pigmented subspecies Proteus anguinus parkelj (black proteus), which has a normal eye structure. In the retina of the black proteus, we found principal rods, red-sensitive cones and a third photoreceptor type, which might represent a blue- or UV-sensitive cone. Photoreceptors in the regressed eye of the blind cave salamanders from the Planina cave contained degenerate outer segments, consisting of a few whorled discs and irregular clumps of membranes. The great majority of these outer segments showed immunolabelling for the red-sensitive cone opsin and only a few of them were found to be positive for rhodopsin. An even more pronounced degeneration was observed in the photoreceptors of the animals derived from the Otovec doline, which are completely devoid of an outer segment, most of them not even possessing an inner segment. Even in some of these highly degenerate cells, the presence of rhodopsin could be detected in the plasma membrane; however, immunoreactions with antibodies recognizing cone visual pigment were negative. In the pineals of all studied animals, the degenerate photoreceptor outer segments were recognized exclusively by the antibody against the red-sensitive cone opsin. The presence of immunopositive visual pigments indicates the possibility of a retained light sensitivity in the blind cave salamander photoreceptors.

Animals↗

PubMed2001

Minireview: genomic organization of the human ERalpha gene promoter region.

The ERalpha gene has been intensively studied for more than a decade. During this long time, multiple promoters used in ERalpha expression have been discovered in several species. Although an already large body of literature describing various aspects of the regulation of ERalpha expression and utilization of different promoters is constantly growing, the inconsistent terminology used by individual authors makes the interpretation and comparison of data very difficult. Furthermore, completion of the human genome project now allows all known human ERalpha promoters to be placed on a physical map. This review describes promoters used in the generation of ERalpha transcripts in human and in other species and suggests a consistent nomenclature. The possible role of multiple promoters in the differential expression of ERalpha in tissues and during development is also discussed.

Animals↗

PubMed2001

ERalpha gene expression in human primary osteoblasts: evidence for the expression of two receptor proteins.

The beneficial influence of E2 in the maintenance of healthy bone is well recognized. However, the way in which the actions of this hormone are mediated is less clearly understood. Western blot analysis of ERalpha in osteoblasts clearly demonstrated that the well characterized 66-kDa ERalpha was only one of the ERalpha isoforms present. Here we describe a 46-kDa isoform of ERalpha, expressed at a level similar to the 66-kDa isoform, that is also present in human primary osteoblasts. This shorter isoform is generated by alternative splicing of an ERalpha gene product, which results in exon 1 being skipped with a start codon in exon 2 used to initiate translation of the protein. Consequently, the transactivation domain AF-1 of this ERalpha isoform is absent. Functional analysis revealed that human (h)ERalpha46 is able to heterodimerize with the full-length ERalpha and also with ERbeta. Further, a DNA-binding complex that corresponds to hERalpha46 is detectable in human osteoblasts. We have shown that hERalpha46 is a strong inhibitor of hERalpha66 when they are coexpressed in the human osteosarcoma cell line SaOs. As a functional consequence, proliferation of the transfected cells is inhibited when increasing amounts of hERalpha46 are cotransfected with hERalpha66. In addition to human bone, the expression of the alternatively spliced ERalpha mRNA variant is also detectable in bone of ERalpha knockout mice. These data suggest that, in osteoblasts, E2 can act in part through an ERalpha isoform that is markedly different from the 66-kDa receptor. The expression of two ERalpha protein isoforms may account, in part, for the differential action that estrogens and estrogen analogs have in different tissues. In particular, the current models of the action of estrogens should be reevaluated to take account of the presence of at least two ERalpha protein isoforms in bone and perhaps in other tissues.

Alternative Splicing↗

PubMed2001

Anencephaly: structural characterization of gangliosides in defined brain regions.

Gangliosides from histopathologically-defined human cerebrum-resembling remnant and cerebellum from 37 and 30 gestational week-old anencephaluses were identified using mass spectrometry and high performance thin layer chromatography combined with immunochemical analysis in comparison to respective normal newborn/fetal and adult brain regions. A novel strategy of nano-electrospray ionization quadrupole time-of-flight tandem MS has been developed for identification of ganglioside components in complex mixtures. By morphoanatomical and histological investigation the anencephalic cerebral remnant was found to be aberrant, while the anencephalic cerebellum was defined as normal. Total ganglioside concentrations in the anencephalic cerebral remnant and the cerebellum were 34% and 13% lower in relation to the age-matched controls. In the cerebral remnant, GD3, GM2 and GT1b were elevated, while GD1a was decreased in the anencephalic cerebral remnant, but enriched in anencephalic cerebellum. GQ1b was reduced in both anencephalic regions. Gg4Cer, GM1b and GD1alpha, members of the alpha-series biosynthetic pathway, and neolacto-series gangliosides were found to be present in anencephalic, as well as in normal, fetal and adult brain tissues, indicating the occurrence of these biosynthetic pathways in human brain. In both cerebral and cerebellar anencephalic tissues, GM1b, GD1alpha, nLM1 and nLD1 were expressed at a higher rate in relation to normal tissue. It can be demonstrated that the anencephalic cerebral remnant, as a primitive brain structure, represents a naturally-occurring model to study the ganglioside involvement in induction of aberrant brain development.

Anencephaly↗