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Biomedical subjects

M Mierzejewski

Publications and source records attributed to M Mierzejewski.

11 recordsLinked to original sources
PubMed2006

Dynamical bimodality in equilibrium monostable systems.

General features of the stochastic dynamics of classical systems approaching a thermodynamic equilibrium Gibbs state are studied via the numerical analysis of time-dependent solutions of the Fokker-Planck equation for an overdamped particle in various monostable potentials. A large class of initial states can dynamically bifurcate during its time evolution into bimodal transient states, which in turn wear off when approaching the long-time regime. Suitable quantifiers characterizing this transient dynamical bimodality, such as its lifetime, the positions of maxima, and the time-dependent well depth of the probability distribution, are analyzed. Some potential applications are pointed out that make use of this interesting principle which is based on an appropriately chosen initial preparation procedure.

Journal Article↗
PubMed2005

Breast cancer predisposing alleles in Poland.

Mutant alleles of several genes in the DNA repair pathway have been found to predispose women to breast cancer. From a public health perspective, the importance of a given allele in a population is determined by the frequency of the allele and by the relative risk of breast cancer that it confers. In Poland founder alleles of the BRCA1, CHEK2 and NBS1 genes have been associated with an increased risk of breast cancer, but the relative contribution of each of these alleles to the overall breast cancer burden has not yet been determined. We screened 2012 unselected cases of breast cancer and 4000 population controls for 7 different mutations in these genes. Overall, a mutation was found in 12% of the cases and in 6% of the controls. Mutations in BRCA1 and CHEK2 contributed in approximately equal measure to the burden of breast cancer in Poland. A BRCA1 mutation was present in 3% of the cases. The missense BRCA1 mutation C61G was associated with a higher odds ratio for breast cancer (OR=15) than were either of the truncating BRCA1 mutations 4153delA (OR=2.0) and 5382insC (OR=6.2). In contrast, a higher odds ratio was seen for truncating CHEK2 mutations (OR=2.1) than for the missense mutation I157T (OR=1.4). This study suggests that cancer risks may be specific for particular alleles of a susceptibility gene and that these different risks should be taken into account by genetic counselors.

Adult↗
PubMed2005

NOD2 variants and the risk of malignant melanoma.

Both hereditary and environmental factors are important in the aetiology of malignant melanoma. Among the risk factors for malignant melanoma are immunodeficiency and immunosuppression. The recently identified NOD2 gene is involved in the regulation of immune function through activation of the transcription factor nuclear factor-kappaB (NF-kappaB). Three common NOD2 mutations -- 3020insC, G908R and R702W -- have been shown to be associated with chronic inflammatory disease such as Crohn's disease, the 3020insC also with human malignancy colorectal cancer. We examined the frequency of the NOD2 variants in 424 patients with malignant melanoma and 649 controls. The 3020insC mutation was present in 6.9% of unselected cases and 7% of the controls (odds ratio (OR) 1.0; P not significant). The mutation was present in 6.8% of 162 cases diagnosed under the age of 50 and in 7.1% of cases diagnosed after the age of 50. A mutation was present in the index case in 5% of 40 familial melanomas (OR 0.7; P not significant). There were no statistically significant differences between prevalence of G908R and R702W in malignant melanoma patients and controls. In conclusion, the three common NOD2 mutations are not associated with increased risk of development of malignant melanoma.

Adult↗
PubMed2004

CHEK2 is a multiorgan cancer susceptibility gene.

A single founder allele of the CHEK2 gene has been associated with predisposition to breast and prostate cancer in North America and Europe. The CHEK2 protein participates in the DNA damage response in many cell types and is therefore a good candidate for a multisite cancer susceptibility gene. Three founder alleles are present in Poland. Two of these result in a truncated CHEK2 protein, and the other is a missense substitution of an isoleucine for a threonine. We ascertained the prevalence of each of these alleles in 4,008 cancer cases and 4,000 controls, all from Poland. The majority of the common cancer sites were represented. Positive associations with protein-truncating alleles were seen for cancers of the thyroid (odds ratio [OR] 4.9; P=.0006), breast (OR 2.2; P=.02), and prostate (OR 2.2; P=.04). The missense variant I157T was associated with an increased risk of breast cancer (OR 1.4; P=.02), colon cancer (OR 2.0; P=.001), kidney cancer (OR 2.1; P=.0006), prostate cancer (OR 1.7; P=.002), and thyroid cancer (OR 1.9; P=.04). The range of cancers associated with mutations of the CHEK2 gene may be much greater than previously thought.

Case-Control Studies↗
PubMed2004

NBS1 is a prostate cancer susceptibility gene.

To evaluate whether an inactivating mutation in the gene for the Nijmegen breakage syndrome (NBS1) plays a role in the etiology of prostate cancer, we compared the prevalence of the 657del5 NBS1 founder allele in 56 patients with familial prostate cancer, 305 patients with nonfamilial prostate cancer, and 1500 control subjects from Poland. Loss of heterozygosity analysis also was performed on DNA samples isolated from 17 microdissected prostate cancers, including 8 from carriers of the 657del5 mutation. The NBS1 founder mutation was present in 5 of 56 (9%) patients with familial prostate cancer (odds ratio, 16; P < 0.0001), 7 of 305 (2.2%) patients with nonfamilial prostate cancer (odds ratio, 3.9; P = 0.01), and 9 of 1500 control subjects (0.6%). The wild-type NBS1 allele was lost in seven of eight prostate tumors from carriers of the 657del5 allele, but loss of heterozygosity was seen in only one of nine tumors from noncarriers (P = 0.003). These findings suggest that heterozygous carriers of the NBS1 founder mutation exhibit increased susceptibility to prostate cancer and that the cancers that develop in the prostates of carriers are functionally homozygous for the mutation.

Adenosine Triphosphatases↗
PubMed2000

Multiple metastases of carcinoma basocellulare into spinal column.

Basal cell carcinoma presents a relatively low potential and local malignancy and very slow growth giving only occasionally metastatic spreading. The frequency of occurrence of metastatic dissemination is estimated in the literature depending on examined population from 0.028% to 0.55%. Metastases are most often found in lymph nodes, lungs bones and internal organs: liver, spleen, kidneys, adrenal glands, pleura and the peritoneum. Authors present a case of a 69-years old female with an extensive basal cell carcinoma of the head convexity, infiltrating the subcutaneous tissue, periostium, bone and dura mater, giving distant metastases to other bone and soft tissue structures of a thoracic spine, which was confirmed by biopsy and histopathological findings of neoplasm tissue in spine. The primary lesion was successfully treated surgically. Despite administered radiotherapy of metastases in spine, progress of the disease during 1-year period was observed. The patient was alive with metastatic tumours present at last follow-up. Basing on the review of the literature and our case report we can distinguish following factors which may increase the risk of occurrence of basal cell carcinoma metastases: the great extent of the primary lesion, deep penetration to stromal tissue, blood and lymph vessel invasion, long history of tumour occurrence and the presence of metatypia in histopathological findings. The above-mentioned case fulfils the criteria of carcinoma basocellulare metastases proposed by Latters and Kessel and may be included to the general registration list of this cancer in the world.

Aged↗
PubMed1997

Prevalence of low back pain among physical therapists in Edmonton, Canada.

Questionnaires were sent to 462 physical therapists in Edmonton, Canada, to determine the prevalence of work-related low back pain (LBP) and to characterize those who reported pain. Of the 311 (67.3%) valid questionnaires returned. 49.2% reported back pain due to work. The occurrence rates of work-related LBP among physical therapists in Edmonton was higher than that of the general population reported in Canada (27%), Great Britain (27%), and the United States (26-29%). There was no significant difference (p < or = 0.05) between those with and without work-related LBP. The initial onset of work-related LBP frequently occurred within the first 5 years of practice as a physical therapist, and before the age of 30. Hospitals and private practices were the most prevalent work settings in which injury occurred. Patient handling, bending, stooping, lifting, carrying, pushing, and pulling were the commonly described activities causing precipitation of injury. The severity of back discomfort had been sufficient to require 13.7% of therapists to stop their work. Despite LBP, 35.3% of the pain sufferers continued to work. Over half (55.4%) of the respondents with current work-related LBP demonstrated little or no disability.

Adult↗
PubMedDate not supplied

[The usefulness of intraoperative high-frequency doppler flowmetry in surgeries for intracranial aneurysms].

The flowmeter enables estimation of blood flow velocity changes in small calibre arteries. The authors examined blood flow velocity patterns in the vessels during aneurysm operations and blood flow velocity and its disturbances inside aneurysm. Evaluation technique, technical data of the flowmeter use are described and the characteristics of the blood flow velocity picture in cerebral arteries obtained by this method is presented. The presented method enables a very precise estimation of blood flow velocity and detection of changes in flow patterns. The method may become very helpful in identification of the vessels in other types of cerebral surgery.

Equipment Design↗