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Biomedical subjects

A Witkowska

Publications and source records attributed to A Witkowska.

At least 19 recordsLinked to original sources
PubMed2006

All-fiber anamorphic core-shape transitions.

We demonstrate low-loss anamorphic transitions between circular and rectangular fiber cores with aspect ratios up to 5:1, and hence improved coupling from a diode laser by using only a spherical lens. Differential hole pressurization and localized heating of a stock photonic crystal fiber inflates the holes at different rates. Some holes are plugged in the fiber end face where pressure is applied, so they remain at ambient pressure. Alternatively, holes of different sizes expand at different rates because the effective pressure due to surface tension differs.

Journal Article↗
PubMed2001

Family with Li-Fraumeni syndrome and no evidence of a germline mutation of the p53 gene or chromosomal aberrations.

Li-Fraumeni syndrome is a rare autosomal, dominant trait of diverse types of cancers in children and young adults, with a predominance of soft tissue sarcomas, osteosarcomas, brain tumours, adrenocortical and breast carcinomas, as well as leukaemias. We present a family with an unusual cancer history fulfilling the criteria of Li-Fraumeni syndrome. Mutational analysis of the p53 gene in constitutional DNA of several affected members of the family did not show any germline p53 defect. Cytogenetic studies did not reveal any structural aberrations.

Journal Article↗
PubMed2000

The evaluation of total dietary fibre content in standard hospital diets during the winter and summer seasons.

The main aim of the study was to determine the total dietary fiber in standard diets for hospitalized patients in winter and summer. In the randomized trial performed in the winter of 1995/1996 and summer 1997, we assessed the dietary fiber content in 12 standard diets with AOAC method. The dietary fiber in the tested hospital diets was derived mainly from grains--average value 12.2 g/day in winter and 15.8 g/day in summer. The second group of plant products to supply fiber in the diet were vegetables. Food portions covered an average of 11.5 g dietary fiber per day in winter and 8.5 g in summer. In spite of the variety of cheap vegetables on sale, a significantly lower content of fiber was observed in summer (p < 0.05). Fruits and fruit products in hospital food contained 1.4 g/day of fiber in winter and 1.7 g/day in summer respectively. We also made a simulation, where white bread, present in every diet, was replaced by dark bread. This let us determine the degree to which the alternative food product influences the diet's composition. The results demonstrate that the replacement everyday of eaten food products may evoke significant changes in dietary fiber contents. The change induced statistically significant differences between diets containing white bread and dark bread (p < 0.001).

Dietary Fiber↗
PubMed1999

[The role of dietary fiber and its preparations in the protection and treatment of overweight].

Optimal amounts of dietary fibre in the diet are regarded as a protective factor against several health disorders such as some alimentary tract diseases, atherosclerosis and coronary heart disease. It is considered that the dietary fibre may help reduce body weight. The preparations of dietary fibre slow gastric emptying and decrease the appetite. However, the reduction of body weight with the application of high fibre diets, but without a change in the eating habits, is not significant.

Dietary Fiber↗
PubMed1998

Nitrate and nitrite content in daily hospital diets during the winter season--comparison of analytical and calculation methods.

A comparison of two methods: analytical and calculation on an estimation of dietary intakes of nitrate and nitrite from six different types of general hospital diets was studied. Studies were performed in the winter season of 1996-1997. It was found that the mean daily intake of nitrates was 85 mg per person in the analytical method, and 65 mg per person in the calculated method. The estimation of average dietary intakes of nitrite was adequate: 1.67 mg per person (the analytical method) and 1.18 mg per person (the calculated method). The main source of nitrates were vegetables, whereas the main source of nitrites was meat and meat-containing products. We suggest that the different methodologies, analytical and calculation methods, for measuring dietary intakes of nitrate and nitrite from diets make it possible to make direct comparisons of intakes.

Animals↗
PubMed1996

The nitrate and nitrite contents in a whole day's hospital diet during the spring season.

It was decided to evaluate the exposition of patients on nitrates and nitrites contained in 6 whole day's standard hospital diets taken in various days. Studies were performed in June 1995. It was found that the mean daily intake of nitrates was 311 mg and the mean intake of nitrites were 2.16 mg per patient. The main source of nitrates were vegetables (85%), whereas the main source of nitrites were meat and meat-containing products. The presented results suggest that the diets containing early vegetables (especially cabbage) may be harmful for human health.

Eating↗
PubMed1993

[ Rhinoplasty in children].

The authors present modern methods of surgeon reconstructions nose's deformation. They analyse transplant material kinds. On the ground of 726 children operated in Department of Pediatric Otolaryngology Warsaw University School of Medicine authors indicate that this operations has not unfavourable influence for anatomical nose's structures and his normal growth. Good present and further functional and cosmetic results of this study points, that this method can be performed in all well-founded cases independently of patient's age.

Child↗
PubMed1981

Pronuclear development and the first cleavage division in polyspermic mouse eggs.

Zona-free F1 (C57B1/10 X CBA/H) mouse eggs were fertilized in vitro with F1 spermatozoa and examined in whole mounts 4.5-5 h or 17-19 h after mixing the gametes. The fertilization rate was nearly 90% with about one-third of eggs undergoing monospermic and two-thirds polyspermic fertilization (2-8 spermatozoa). In all monospermic eggs the sperm head developed into a large pronucleus. In polyspermic eggs either all or only some of the spermatozoa had completed the process of transformation, while the remainder were arrested at the early phase of pronuclear development. During the first cleavage division these pronuclei condensed but separate chromosomes did not differentiate and therefore could not contribute to the genome of the embryo. The condensed pronuclei were passively displaced to one or both blastomeres. The number of decondensed sperm heads present in the egg shortly after fertilization was therefore not always equivalent to the ploidy of the future embryo. The duration of the first cell cycle appeared to be related to ploidy (number of functional = 'advanced' pronuclei), with the monospermic eggs dividing first.

Animals↗
PubMedDate not supplied

Human telomerase RNA as endogenous control in endometrial tissue.

Telomerase is a reverse transcriptase that adds repetitive telomere sequences to the end of chromosomes, which is thought to be essential for cellular immortality and oncogenesis. The enzyme consists of three subunits: human telomerase reverse transcriptase (hTERT), human telomerase RNA (hTR), and telomerase protein 1 (TP1). The hTERT subunit determines the activity of telomerase as an enzyme and is detected in most human tumors and regenerative cells. But many studies have revealed that hTR and TP1 are expressed constitutively. This results suggest that the hTR and TP1 subunits may be potentially good markers of endogenous RNA control. Endometrial dating was determined from the pathomorphology of the endometrium and classified into normal proliferative endometrium, endometrial hyperplasia (simple, complex, and atypical), and endometrial adenocarcinoma. The analysis of the expression of the hTERT, TP1, and hTR telomerase subunits was performed by a quantitative polymerase chain reaction method, based on fluorescent TaqMan methodology (ABI Prism 7,700 Sequence Detection System) capable of measuring fluorescence in real time. The aim of the study was an analysis of the expression profiles of genes encoding hTR and TP1 telomerase subunits in normal endometrium, endometrial hyperplasia, and adenocarcinoma for the estimation of the possibility of once application in endogenous RNA control of gene analysis in the endometrium. The nonparametric Mann-Whitney U test and analysis of variance Friedman test were used to evaluate the variation in telomerase subunit mRNA level between normal endometrium, and endometrial hyperplasia and adenocarcinoma. The results confirm the hTR subunit expression as a good marker of endogenous control in quantitative analysis of gene transcription in endometrial tissue. TP1 subunit transcriptions have not been detected constitutively in our study.

Adenocarcinoma↗
PubMedDate not supplied

Effect of age on creatine, nitrogen and phosphorus concentrations in the skeletal muscles of cockerels.

Effect of age on creatine, nitrogen and phosphorus concentrations in the skeletal muscles of cockerels. Acta physiol. pol., 1985, 36 (3): 201-207. In the studied life period from the age of 1 to 7 weeks the concentration of nitrogen increased in the muscles and that of phosphorus decreased. The relation between creatine concentration and the share of creatine nitrogen in the total nitrogen pool in the muscles, on the one hand, and the age, on the other hand, was curvilinear; the highest values were observed in cockerels aged 3 weeks. No significant differences were demonstrated in the concentrations of these components between the superficial pectoralis muscle and the deep pectoralis muscle. In the muscles of legs the concentrations of creatine, nitrogen and phosphorus were lower than in pectoralis muscles.

Aging↗